For many years, if not decades, power amplifiers were one of the single biggest (component) disappointments. In fact, they had even more serious compromises than preamplifiers. While there were a lot of "good" amplifiers, few were "excellent" and even fewer were "superb". As for "great", I would have passed on naming even one amplifier until recently. However, there are finally a few amplifiers, auditioned in the last few years, that appear to have earned that accolade.


The standards here are higher than others, and this is why you will find only 2 or 3 amplifiers in Class A, not the 50 or more you will find in Stereophile, because "Greatness", even when loosely defined, is never that common in any human endeavor.

I would read this section more carefully than any other, because there are more conditions, caveats and warnings than in any other component category. The only good news about amplifiers is that almost all of the best models weíve heard are under $10,000.

This is the one category where "big money" rarely buys you better sound, regardless of what youíve read elsewhere. In fact, just the opposite is almost always true. There is very good reason for this...

The Missing "Megabuck" Amplifiers

You will not find even one megabuck (over $ 20,000), super-power amplifier listed here, either solid-state or tube. Why?

None of them, regardless of their engineering, execution or reputation, can approach the sound quality of the good low-power amplifiers. The all have signal paths that are far too complex to preserve the subtleties and essence of music, particularly acoustical, but even electronic. They only excel in brute force dynamics, outer detail, soundstage size and low-end control with speakers of inferior design.

With these amplifiers, you are paying (a lot) more for lower quality sonics, and that is one reason why you will inevitably see them for sale at a fraction of their retail price within months of being sold. The other reason is that the manufacturer's markup on these ultra expensive amplifiers is usually much higher than on other amplifiers. Why?

The manufacturers and distributors have realized that "prestige", based on an artificially high price, is much more important to the prospective purchasers of these components than the actual sonic performance. (Loudspeaker manufacturers and distributors had learned this same "lesson" years earlier.)

(For more on the subject of: The inevitable sonic problems of "components with excessive size and complexity", please go to My Audio Philosophy.)


A reader recently sent me an email, with a question other readers have also asked or inferred, either directly or indirectly. Here it is:

"I can intuitively grasp why higher efficiency in a loudspeakers would be a plus. I do not understand why (minimum 6 ohms everywhere) is mandatory to achieve minimalism. Why would loudspeakers (93 db) with lower impedances and first order crossovers violate fundamental principles?"

My Reply- The speaker's impedance ("load") is almost as important as its sensitivity, maybe even more so in some cases.

This is because a speaker with a low impedance, even if it's only at particular frequencies, will usually cause a single-ended-triode (SET) amplifier to either noticeably distort, or even entirely clip. These amplifiers rarely have the current reserves required for such a low impedance load.

If that wasn't bad enough, even if/when the amplifier is not distorting, its frequency response will look like a "mountain range" with a speaker which has a varying impedance. All of these problems are very audible, and they are why some audiophiles feel that all SET models are for "fools", or for the (figuratively) deaf.

I've had direct experience with this problem on several occasions. My prime example: The Wilson WATTS are pretty sensitive compared to most other speakers, but they have/had dramatic impedance dips at certain frequencies, causing all the single-ended amps I had, even those with 20 watts or more of power, to distort. It was this speaker, more than any other, that proved to me that sensitivity was only half the solution. I wish it were otherwise, but it isn't. I ended up building my own custom crossover for my WATTS. It was the only certain method to eliminate the problem.

I believe an easy speaker "load", both in sensitivity and impedance, is the key to putting together a truly great audio system, so all serious audiophiles will eventually have to tackle this issue.

Amplifiers and Speakers-The Cruel and Unavoidable Choice

It's been my/our experience that, in virtually every instance, when you compare amplifiers using speakers that don't require huge amounts of current and/or voltage to drive them, the lower powered and/or simpler designs (of equal build quality) will sound superior; meaning noticeably more natural and less electronic. Within this amplifier hierarchy then; the largest solid-state amplifiers will sound the worst (while having the greatest speaker versatility) while low-powered SET amplifiers will sound the best (while having the least speaker versatility). Why? The lowest-powered amplifiers almost always have the most minimal circuit, causing the least musical damage.

This means there is an unmistakable general "formula" or "rule" to all of this: The inverse relationship between the amplifier's speaker drive capability and its inherent sonic quality. In other words: The more speakers an amplifier can drive without being compromised, the more compromised are its inherent sonics, everything else being equal.

The sonic price for greater speaker accommodation is greater signal degradation. It's that simple.

Analogy- It's like the difference between an all-terrain vehicle and a racing car. Sure, you can always get from any Point A to any Point B with the all-terrain vehicle, but it's no contest when the two designs are competing on a smooth and straight highway.


I recently received a depressing letter from a reader who purchased a VTL Ultimate* preamplifier, on my advice and recommendation, only to see it break down after a few months, with the required repairs too expensive to be economical, at least for this reader, who is in the tube elctronics business no less. So readers, please...

When you are buying an audio component used, especially an older tube unit from an unknown source, make certain there is some previous "feedback" or some resource if there are problems. Either that, or make sure the price you pay is low enough to allow you to still spend something to bring it up to top "stock" performance. (Modifications can come later.) Ideally, you should hear the component in your own system, and check it out personally, BEFORE the purchase. Fortunately, the nightmare this upset reader experienced is relatively rare, at least in our audio world, but always be careful before you make your commitment.

*This preamplifier is generally reliable, so I'm not trying to make an "example" out of it, but the reader informed me that the (VTL) factory won't be of any help (with schematics or parts lists), so be extra careful with it.




Coincident 211PP Dragon MK. II Mono Amplifiers

I finally found the time and assistance that I required to properly audition these amplifiers (which I've had for a year now). I've heard them on both the monitors and the subwoofers of the Coincident Pure Reference Extreme (PRE) (doubled up). I even listened to one of them "mono" (one channel). They were later directly compared to the Coincident Frankenstein amps on the monitors, and to the original Dragon amps on the subwoofers. Relevant Details- This pair of Dragons were fully broken-in by prior parties before I received them (shows and other reviewers, including the late Harry Pearson). They are using the stock Psvane 211 output tubes. This is what I, and my visiting associate, observed:

The Dragon Mk. II is an outstanding amplifier. It is both the finest push-pull amplifier I've heard, of any type and at any price, as well as the finest amplifier within its power range (which is probably redundant to state). Compared to the "original" Dragon, which I've now lived with for more than 8 years, the II is cleaner and more refined sounding throughout the entire frequency range, plus it has a lower sound-floor. The bass is a little more detailed and controlled (like an "iron grip") than the original Dragon. On occasion, it also has slightly more impact. More importantly, the II is more cohesive with the Frankenstein amplifiers playing on the monitors in a biamped system (which is critical for me). The improvements in the bass, in isolation, may not appear to be much, but this is one of those welcome occasions where the sum is greater than the parts.

There are other improvements besides just the pure sonics, though they are directly related. The Mk. II is quieter and cooler then the original Dragon, mainly because it now has a second power transformer, along with other advances in the power supply as well (the details are at the Coincident website, see link below). Accordingly, the II is larger than the original, though much more elegant in appearance with its stainless steel chrome-like covers. The two output tubes run cooler as well, so their life is now extended. In short, the Mk. II is superior in every manner possible to the original model.

The price did go up 10%, which is actually less than the accumulated inflation over this period of time ($ 10,000 to $ 11,000), and the sensitivity seems reduced by around 2 db or so (which means there was a circuit change, though the tube complement remains exactly the same). All of the above improvements were heard pretty quickly and are quite straightforward, which is why I have no interest in providing any lengthy descriptions. What I feel is more important is whether and/or how this component changes the present amplifier landscape. I have given this some thought, especially for the owners of the Pure Reference Extreme speakers, and below is my thinking at this time.

The Dragon or the Frankenstein?, Or?

The Dragon is the closest I've heard a push-pull amplifier come to equaling the sonic advantages inherent in a really good SET amplifier, but it's not there yet. And, to be brutally frank, nor will it ever be, mainly because I don't believe it's technically possible for any push-pull amp to achieve that level of performance. If it were possible, SET amplifiers would be functionally obsolete because, outside of their unique sonic advantages, they have no redeeming qualities with the exception, for a tiny minority, of nostalgia. That said, it is obvious that the Dragon will outperform the Frankenstein on the vast majority of speakers of interest to audiophiles, current or from the past. The Bottom Line here is quite simple: The Frankenstein is a specialist amplifier, designed for those few speakers that are very easy to drive (in both sensitivity and impedance), while the Dragon can drive almost any speaker. This then brings us to a speaker that both amplifiers can drive, the Pure Reference Extreme, which is also ultra-revealing as well, thus making it easier to observe any deficiencies of the sources and amplification, always a bonus for any critic.

Actually, I discussed this exact same issue four years ago in 2011, and while the Dragon has now been improved, so had the Frankenstein somewhat earlier, and by around the same degree. What this means is that the sonic performance relationship between the two amplifiers is still basically the same as when they were first released back in 2007, and so then will be my perspective and advice. Accordingly, I will simply reiterate what I wrote four years ago about this subject, in almost the same words as I used then:

1. When played full-range, the Frankenstein amplifiers are still preferable overall, most of the time. They only demonstrate their shortcomings, in an obvious manner, on the most challenging of records, which require very high volumes and/or demanding bass notes. They are more vivid and present than the Dragons and the harmonics are more natural. The Frankenstein excels in purity, transparency, naturalness, ultra-low sound-floor and a lack of an "electronic character". Even simpler, the Frankenstein is a master of "voices".

2. The Dragon amplifiers, while obviously outstanding performers, are only superior in attaining ultimate volume levels and in the bass frequencies, though the latter improvement is usually subtle and only obvious on music with serious bass challenges. Even simpler, the Dragon is a master of "drums", where "control" is an extra requirement.

In the end, choosing between the amplifiers, assuming the speakers are the PRE or something similar, comes down to "quality versus quantity". If the listener requires the Dragon's extra power for a variety of reasons; an unusually* large room, high listening levels, and extra challenging music, plus "peace of mind" that the amplifiers will never "give up" under any circumstances, then I would get the Dragons. Otherwise, the Frankensteins are to be preferred.

*It must not be forgotten that I have a large room and play large orchestral music on a regular basis, and I still prefer the Frankenstein amplifiers full-range.

However, despite this analysis, I believe the choice between the two amplifiers, both of them playing full-range, is somewhat arbitrary and superficial, if not misleading. In short, if the end goal is to fully optimize all of the potential performance of the Pure Reference Extreme (hearing it at its very finest), then the real answer is "Neither", because there is a third option (see below) and, in my experienced opinion, it is the best option, period.

The Correct Answer is: "Or?"

The best sound I've heard with the PRE, without any doubt, was when they were bi-amplified, with the Frankensteins on the monitors and the Dragons on the subwoofers. For the best of all worlds, which unfortunately comes with a monetary price, we must now discuss bi-amping (which makes more of an improvement than even doubling them up). To make things crystal clear, no single amplifier, at any price, can equal what the Frankenstein and Dragon can do together, and I can state that with absolute confidence even though I obviously haven't heard every amplifier in the world. This is because no one amplifier, no matter what its capabilities, can overcome the technical problems inherent in playing the PRE Full-Range. Only dedicated amplifiers, independent electrically from each other, can avoid those problems, which thus means bi-amping is a necessity to achieve the highest potential performance with the PRE (or any other speaker with a similar design).

The sonic benefits of bi-amping, which are very easy to observe on the PRE, depend on which amplifier is originally playing full-range. If it's the Frankenstein, with the addition of the Dragon not only will the bass obviously have more power, weight and impact, the midrange will also improve to a surprising degree, with extra purity, speed and even headroom. If the Dragon is the "starter amplifier", the addition of the Frankenstein will reduce the headroom, but the various improvements in the midrange will more than make up for it. The bass will remain basically the same. Further, any "theoretical dream amplifier" will/must noticeably compromise the PRE's midrange if it simultaneously drives the subwoofers at the same time. This technical problem can not be finessed, which closes this issue. (A Caveat and Exception- An electronic crossover/buffer can compromise the midrange and bass of the PRE even more than using a single full-range amplifier, which I learned from direct experience.)

So far, I've been focusing on the Dragon and Frankenstein not only because they both come from Coincident, but also because they share a very similar overall design. In effect, the Dragon is the closest amplifier possible to the Frankenstein if the goal is to have around 10 db more power, thus making it the ideal amplifier to use on the subwoofers if the Frankenstein is used on the top. Still, there are other good choices for the subs as well, and they all cost less than the Dragon; The ASL Hurricane, Tutay/Altec 1570, Canary CA-339 etc. (Check Classes B/C of the Reference Amplifiers for other choices), but none of these amps will equal the Dragon for either overall performance and/or cohesiveness.


To summarize everything discussed above, in the simplest of terms:

1. The Dragon II is a very well thought out improvement of the original Dragon, which was already a formidable amplifier in its own right. The II is superior in performance, practicality and appearance, which thus covers every base imaginable, and it costs only 10% more.

2. While the Dragon can drive a far greater variety of speakers, the Frankenstein SET amplifier will still be the better choice, most of the time, on Coincident's own Pure Reference Extreme (PRE) speakers (or other speakers similar to the PRE).

3. However, bi-amping, using both amplifiers, is still the only method to fully maximize the PRE's capabilities. No one amplifier, at any price, can equal their combined performance due to inherent and unavoidable technical factors.

This brings me up-to-date on the Coincident components that are relevant to me. I have no plans to audition any other Coincident component at this time. If a reader requires even more details concerning the issue of choosing an amplifier(s) for the Pure Reference Extreme, I would suggest contacting Israel Blume, the designer/owner of Coincident, who has made many more comparisons than I have. See the Link below.

Relevant Links:

Coincident Speaker Technology

My Audio System



This is, without a doubt, the finest amplifier, overall, I have ever heard. Three of my associates have also heard this amplifier, in my system, and agree with this opinion and evaluation. Since my former "reference" amplifier, the (highly modified) Golden Tube 300B (now in Class B Upper), has previously survived every challenge since 1996, I feel the Frankenstein must receive an extensive and in-depth examination from me at this time.

Accordingly, I have decided to create a dedicated file for this important amplifier: THE COINCIDENT FRANKENSTEIN FILE. This file contains everything I've ever written about the original Tektron/Frankenstein and the Coincident Frankenstein, as well as all the Readers Letters.




Note- There is an updated version of this amplifier (see above) now available. What is below was written in 2007.

I've now listened to these amplifiers long enough, and in a revealing enough manner, to come to a confident assessment about them: This is the finest high-power amplifier I've ever heard. I've already mentioned their superb bass reproduction (see below), and now I've also heard them on the Ars Acoustica satellite, from around 100 Hz and above. That listening session (and another) was relatively short because of a component mismatch, as will be explained below, but long enough for our purposes. Overall, we (my associates and I) have experienced a combination of strengths we've never heard before.

These amplifiers possess three areas of pre-eminence, and one of them is unprecedented in our experience:

1. The dynamic contrasts, shifts and intensity are in a class by themselves. It is the first amplifier I've ever heard that allows a good dynamic speaker to display an intensity (startle, goosebump and shock capability) which is reminiscent of a good horn speaker. Every other amplifier I've heard in my life is compressed, to some degree, in comparison with the Dragon. Certain transients actually sound like their "shot out of a cannon".
2. It has a huge soundstage, maybe the largest I've ever heard, but I've heard nothing larger than it.
3. It is very immediate. More so than any high-powered tube amplifiers I've ever heard, and only equalled by the finest SET amplifiers or rare transistor models.

It is also very neutral, but if you're hoping it can also equal the finest low-powered SET amplifiers, such as the Coincident Frankenstein or the Golden Tube 300B, in their unique strengths of ultimate purity, transparency and an ultra-low sound-floor, I must sadly dash that hope. Just as it took only a few minutes (or less) to hear the Dragon's obvious strengths (above), going back to the finest SET amps I know quickly confirmed that there is still a noticeable comparative "gap" with the Dragon's reproduction of the most subtle elements of music.

However, I want to make my opinion and perspective clear: The Dragon will sound better, on a greater variety of speakers, than any other amplifier I've ever heard, or I'm even aware of at this time. No other amplifier I've heard can equal its unique combination of real dynamic force, purity, neutrality, speed, image size, naturalness and "completeness" on average (and difficult) load speakers. If someone is looking for their "final amplifier", which sounds outstanding full-range, on virtually any speaker, of any type, the Dragons would be my first choice.

I plan to eventually go into more detail about the Dragon's performance. Meanwhile, I have already extensively heard the Dragons on my subwoofers. Here's the essay I wrote about these experiences. I feel it is still relevant.

January 2007 Bass Amplifier Essay

These are the finest amplifiers I've had on my Ars Acoustica System Max Subwoofers. I can not state that they are superior in every single sonic parameter, but they are definitely the best overall. In most instances, such a high level of bass performance would be wasted on a single octave (20 to 40 Hz), but in my case the "subwoofers" go up to around 160 Hz, which is three entire octaves, and thus highly critical to the ultimate sonics of my system.

While I have no present intention of designating an amplifier as a Reference strictly on its bass frequencies (though maybe that's something which should be further thought out in the future), I would like to take this opportunity to discuss my past experiences with the Ars Subwoofers, and the most interesting amplifiers I've used with them. This should be relevant to a wide audience of audiophiles, because it deals with bass reproduction in general. I also would like to post my thoughts and experiences on the utilization of subwoofers, which I've now used in my various systems for almost 30 years. This will all be necessary to set the stage and to put things in perspective.

Experiences with the Ars Acoustica System Max Subwoofer

I've had the Ars Acoustica speakers for almost 10 years now, and I've tried countless amplifiers on them, on both the satellites and the subwoofers, and sometimes even one amplifier driving them full-range. This was easy and convenient for me, because I had my audio store in the same building in which I lived between 1996 to 2001. At this time, I'm only focusing on my most interesting experiences with the System Max subwoofers.

The first amplifier I used on the Ars subs was the Parasound HCA-2200; one pair of them switched into mono operation. The Parasounds were superb bass amplifiers, especially for the money, though they couldn't operate into a really low impedance load in mono. Since the Ars is almost exactly 4 ohms, and very flat, this was not a problem. I had originally picked up the Parasounds for my previous woofer system, the Tympani IV bass panels (in heavy granite frames), which required huge power (500 watts minimum) and control, though they had no real response below 30 Hz, so they weren't a true "subwoofer". I also had the ultra-rare Concentric Speaker "Super-subs" (which I still have, and will discuss later).

I was very happy with the Parasounds, but after a lot of experimenting with a number of amplifiers (now mainly forgotten), I eventually replaced them with a pair of Atma-sphere M-60 Mk. II OTL amplifiers. This was a surprise to me, considering the relatively low impedance of the Ars sub. The Atma-sphere didn't have nearly the power of the Parasounds of course, but they went just as low, were just as controlled, and they passed through more musical information in a natural manner. In effect, I traded some quantity for some quality. This brings us to around the year 2000. Two more amplifiers, both of them using (Direct Heated Triode) tubes, then entered my audio life.

The next amplifier I used, the Altec 1570B, with heavy modifications designed by (the late) Tom Tutay, ended up being my long-term choice (6 years), though it was actually my second favorite. The Altec sounded very similar to the Atma-sphere, but it had more power. It was, in the end, in my room and system, a combination of the best qualities of both the Atma-sphere and the Parasound. Just when I thought I had found my "final" subwoofer amp, another contender arrived out of the blue (literally, since it was metallic blue). This was the Viva Aurora 572 amplifier, imported from Italy, which was also visually stunning.

The Aurora was an expensive amplifier, the most expensive by far I had ever owned, but I was able to get a "super deal" on them. I was lucky, Viva was just then changing this model, converting it from the "obsolete" 572 output tube to an 845 output tube. I first played the amplifier in my store, comparing it to every serious amplifier I had, and could find. It didn't take long to appreciate its outstanding performance. In fact, it proved to be noticeably superior to all of the other amplifiers. It was especially impressive on the Coincident Super Eclipse, even startling highly critical listeners who had never liked that speaker in the past. After this encouraging experience, I decided to put it in my own system, which was the toughest and most revealing test I had, or knew.

The Viva Aurora 572-My Final Toronto Fling

I still remember one of my associates and I, plus a helpful and enthusiastic customer, bringing the Viva Aurora 572 amplifiers into my personal listening room. We were all excited, because we had just heard the Vivas easily outperform the finest amplifiers I had in the store. This time, we were going to compare it with my (highly modified) Golden Tube 300B amplifiers. The Golden Tube 300Bs only drove the satellites of the Ars Acoustica System Max, while the (modified) Altec 1570B amps drove the Ars subwoofers.

It didn't take long to hook up the Vivas, and then warm them back up, while also resetting the subwoofer sensitivity. The Auroras sounded superb. We played a variety of music, all records, until we felt familiar enough with their sonics to go back to the Golden Tubes. The only surprise at that stage, for me anyway, was that the Vivas had only a very slight advantage during the loud passages. I was expecting something much more noticeable in that area.

We then warmed up the Golden Tubes with different records, and after 30 minutes or so, we started playing the same records we had heard with the Vivas. We heard the differences almost immediately, and they were obvious to all of us. As good as the Vivas were, the Golden Tube amplifiers, in comparison, were in another sonic league. They were so natural and pure, while lacking any type of electronic signature, that it felt like nothing was even in the system to describe. In simple terms: It was almost as if they had an infinitely low "sound-floor".

We all had different reactions: I was disappointed, while my associate told me he wasn't surprised at the results, but had kept quiet to avoid influencing us. Meanwhile, the customer was so shocked by what he had heard, that he could hardly speak. He looked closely at the Golden Tube 300Bs, which appeared to be put together with spare parts in someone's garage, and couldn't understand how it could perform at such a high level. I carefully explained the simplicity of the Golden Tube's circuit, and the modifications that had been made. Still, I'm not sure I totally convinced him that it was all "science". Then, wanting to complete the picture, I asked my two assistants to help me with one final experiment; replacing the Altecs with the Vivas on the Ars subwoofers. The results: Paydirt!

The sonic differences between the Altecs and the Vivas were easily noticeable, though subtle at times. The Altec had a little more power and drive, while the Viva was more natural and pure, and also had a little more detail. However, most importantly to me, the Viva had a lower sound-floor. This, in turn, lowered the entire system's sound-floor. It was another "quantity versus quality" choice, and once again I chose "quality". My system had never sounded so natural, and "disappeared" as well. Unfortunately, I only had this combination for a month or so. I soon left Toronto for Florida as planned. I felt that the Vivas were somewhat of a luxury at that precarious moment of my life, so I sold them to a lucky customer. Around 9 months later, now in Florida, the modified Altecs went back into my new system, and that's where they've been for most of the last 4+ years, until now...

Enter the Dragons!

I've had the Coincident Dragon amplifiers in my system for around a month now. I would have written my report earlier, considering it's only bass frequencies being discussed here, but I've also changed my turntable set-up (VTF), plus there's been some (final hurricane related) construction work on my house which caused even further delays. This is all in addition to the normal tube amplifier break-in process, since I received the pair virtually brand new. Let's start with a short physical description of the Dragon amplifier.

It's a push-pull design, using (two) 211 DHT output tubes, with a 6EM7 input tube and a single 300B as a driver (there are no tube rectifiers). I'm using a Svetlana 300B for now, and the 211s are NOS GE. Israel Blume, who created the basic design of the Dragon, claims that this output tube is critical to attain the amplifier's ultimate performance, though they are costly. It has an accessible volume control on the top plate. This amplifier is very well built, with an industrial, heavy-duty "no-nonsense" appearance. It is rated at around 80 watts per channel and weighs around 50 lbs.

It requires absolutely no biasing, which is a serious advantage considering that the output tubes have 1,200 volts on their plates. There is one downside from the high voltage though, the amps do get quite hot, and are painful to touch after they're on more than two hours or so. I looked inside, which I don't recommend to others, and can testify that I couldn't find even one modification opportunity. This is the first stock tube amplifier I have ever known where I could make such a claim. (Since this was written, I now think that the volume control can be improved.)

Compared to the Altec/Tutay 1570B, the largest differences I heard, which anyone can hear, are as follows:
1. The Dragons are quite a bit less sensitive (maybe 6 dB or so), because it has fewer gain stages.
2. The Dragons reach noticeably deeper into the lowest bass frequencies (below 40 Hz)*.
3. The Dragons are purer and have a lower sound-floor.

The Dragons were also better in other areas, though to a more subtle degree; control or tightness, mid-bass impact and drive, and superior retrieval of detail. I can't think of a single area where the Altecs exceeded the performance of the Dragons in the bass, though I don't want to give the impression that there was a "night and day" difference between them. The Altec 1570B is simply too good an amplifier to allow such an extreme expression to be used honestly.

*This made it extra difficult for me to balance the subwoofer with the satellites, since the subwoofer's own balance was now different. I didn't hear this specific problem with the Altecs in my Toronto listening room, because the room itself rolled off the deepest bass frequencies.

The only question still in my mind is something I have no chance of answering: How does the Dragon's sound-floor compare to the Viva Aurora 572's? I have a strong feeling that they're very close, based on my similar gut reactions when first hearing both of them compared to the exact same amplifier. Still, 5+ years is just too long to remember something subtle like this definitively. The only statement I can make with confidence is that they're both "in the same ballpark".


The Coincident Dragon is as good as any other bass amplifier I've ever used in every area of bass performance. This may not be relevant to the vast majority of audiophiles, but it's still important to know, because we're talking about 3 octaves of music. Whether having this level of bass performance is worth $ 9,000 is a personal choice, but I know nothing that equals it for less money. The main qualification of the above claim is the Ars Acoustica Subwoofer itself. Keep in mind that this is the only subwoofer I've used so far with the Dragons, so a short description of the Ars Acoustica is in order.

The Ars is the most revealing (sub)woofer I've ever heard, overall, in this frequency range (20 to 150 Hz). It is made out of a dead (casted) metapolymer cabinet, with three 8" woofers. It is natural, clean, highly detailed and has a very low sound-floor. However, other subwoofers I've heard have greater weight and impact. Its "load" on the amplifier is slightly easier than average. Its sensitivity is around 92 dB/1 watt, while its impedance is a low, though flat, 4 ohms. It will take time, and other audiophiles' experiments, to learn how the Coincident Dragon deals with truly difficult loads, especially those speakers with really low and varying impedances.

Finally, to be frank, I seriously looked for some good reason why the Dragon should NOT be in Class A. I couldn't find any. This search for a "reason" was partly because of the now unusual result; Two separate amplifiers, from the same company, both being in Class A at the same time. This has never happened before. I realize it looks "suspicious", especially since the owner of Coincident, Israel Blume, is a close friend of mine. However, if I didn't report and objectively evaluate what I (and three of my associates) have heard, I would be doing both the readers of this website, and Blume, a disservice. Time will tell whether my judgment about this amplifier is correct, or not.



This is the second best amplifier, overall, I've ever heard. Only the Coincident Frankenstein has proved to be superior. The Vaic, now discontinued, was an all-out attempt to create a state-of-the-art SET amplifier in the late 1990s. (I wish I heard it back then!) Each mono amplifier weighs 65 lbs, and they cost $ 22,000 for a pair. As far as I know, it was built to Vaic's specifications by Mastersound, located in Italy. Its appearance, all chrome, is stunning. Its performance, when it came out, was a "breakthrough" for (SET) amplifiers.

The Vaic is outstanding in every sonic parameter; naturalness, purity, transparency, speed, dynamics, "imaging" and the frequency extremes are not only there for once, but the deep bass has real power (see the Pure Reference essay). This assessment assumes that the Vaic will be matched to the "right speaker", because, as a SET amplifier, it lacks feedback. It uses a VV52B DHT output tube, which is similar to a 300B, but it can handle far higher voltage and bias, so the power rating is over 20 watts per channel. Compared to the Coincident Frankenstein, the Vaic still sounds a little more "electronic" and it's also slightly smeared and veiled.

The (required) modifications are pretty straightforward; Teflon coupling capacitors, film capacitor bypasses on the power supply caps, and improved internal wiring. These amplifiers are rather rare, but worth searching for. There may be a newer version of this amplifier by Ayon, but they cost $ 30,000 (8 years of inflation I guess).

Further- For those "sceptics" who want to know what is the finest amplifier I've ever heard, that also has no association whatsoever with Coincident (whose owner, Israel Blume, is a close friend of mine), the Vaic is that amplifier. In short, if the Frankenstein M300B did not exist, I would be now (desperately) searching for a pair of these Vaic amplifiers.


There are other amplifiers available with even less power (using 2A3, 45, 50 output tubes etc.) that are (supposedly) even more revealing and purer sounding. None of them are References at this time, because we are unaware of a single model that even equals the performance of the Coincident Frankenstein (let alone surpasses it). If such an extraordinary amplifier is ever discovered, it will be reported. However, don't also overlook the fact that only a tiny number of speakers can actually be driven by these amplifiers. That "problem" is irrelevant now, but it's a serious and unavoidable issue that will have to be addressed by any prospective owner/user.





I have not heard these amplifiers myself, at least that I can remember, but one of my "associates" had a thorough listening session with them. This associate has extensive experience with DHT and SET amplifiers, along with countless "traditional" designs, and has a highly revealing system. Here are his observations at the time, April 2006, with some minor editing:

"The Wyetech Topaz 211 Mono amps are the finest sounding high powered SETs I have experienced. They have tremendous drive capability, excellent bass extension and punch and overall purity, while detail and transparency is very single-ended DHT like. They perform like big, pentode tube amps, in those ampsí area of strengths (dynamics, weight, etc.), yet possess the single-ended "magic".

Compared to the best SET 300Bs, or type 50 or 45 based amps, the Topaz yields a smidgen of purity, but it takes an exceptionally high resolution system for this to be noticeable. The Topaz is slightly more forgiving, with transients a tad rounded by comparison to small SETs. The compromise, in this area, is the smallest I have experienced in a high powered amp. The Wyetechs are superior to the Canary CA 339s in virtually in every respect. They are more transparent and more dynamic and gutsy.

Build quality is state of the art. Each amp weighs in excess of 100 lbs. All wiring is point to point, the power supply uses only polypropylene caps etc. Output trannies are the superb Audionotes*. To achieve the performance I am describing, the amps must be modified. The Solen metalized polypropylene caps have to be replaced with V Caps or other top of the line caps. Solenís new polypropylene film and foil caps are excellent. They sound superb and are very reasonably priced. Also, all the power supply caps must be bypassed with .01 mfd Ė 1200 V film and foil caps.

For any speaker requiring more than 20 watts, and yet 45 watts is sufficient, the Wyetechs are the amps to have. Nothing sounds as good amongst the competition, or is built as well. For those who are satisfied with 7 watts, the Topaz will be slightly, but somewhat, compromised. Even under these conditions, if a more forgiving sonic portrayal (by reducing some of the rough edges of poorly recorded material) is desired, the Topaz is the amp of choice."

Personal Note- I trusted my associate's experience and judgment enough to have originally placed this amplifier in the "Medium Power", Class A. Recent developments have now changed its relative status. The superb, and also less expensive, Canary CA 339 (which he also brought to my attention), is also still within this same list, which means it is still a Reference, but it's no longer recognized as the "best of its type". However...

*Caveat- A reader (within an hour of the original posting!) informed me that the current version of these 211 mono amplifiers no longer have Audionote transformers, but are instead now using Bartolucci output transformers. We have NOT heard these latest models, so caution is advised at this time.

Meanwhile, my associate, who owns and auditioned the amplifiers, also sent me a short clarifying note concerning this issue:

"Mine are the older model with the Audionotes. Wyetech switched to the Bartolucci because Audionote ceased production of the output trannies. I have heard from a few sources that the Bartolucci is inferior.

(I) just read an old Vacuum Tube Valley report (Issue 9-1998), where a comparison of output transformers with 211 tubes was conducted. The Audionotes received a rave review, while the Bartolucci was found to be noticeably rolled off in the highs, with a colored, albeit pleasing, sound overall."

Latest Update- I just received this update from my same trusted associate. This entry focuses on the 211 output tubes. Here it is, with some slight editing:

"A couple of days ago, I replaced the stock Valve Art 211s with NOS GE VT-4C (211) ĖManufacture dateĖAug /1944, and the resultant improvement in sound staggered me. ...The leap in sonic performance was greater than any tube substitution I have made. As good as the Topaz was prior to the tube change, the GE 211s wrought a refinement to the sound that was simply not there before. The typical Chinese tube glassiness (apparent with the Valve Art 300Bs), was eliminated and replaced with a silky smoothness that I did not believe a 211 capable. Overall purity and transparency was enhanced, as well as a lowering of the noise floor. A stunning improvement to be sure. There is no question that I have not heard a single ended amp, with this power, sound as good."


Important Note- This was written before the arrival of the (superior) Coincident M300B Frankenstein MKII

The former audio manufacturer, Golden Tube, came out with (at least) three amplifiers using one 300B output tube per channel. Two of them were MONO. One of them, the original design, used a 6SL7 input tube. The result is an amplifier of between 8 to 10 watts in the midrange and upper bass, depending on the brand of the 300B used.

The later mono version had the option, with a switch, of using a 12SL7 or a 6SL7. This model is also a Reference, but not when using the 12SL7. The third version was a stereo amplifier, which also had a different circuit, and didn't sound as good. It had some some good qualities, but it was not the equal of the two monos, and it is not in this class.

The stock performance of the Golden Tube 300B is not equal to the superb Wavelength Cardinal, or even the much more powerful Wytech Topaz for that matter. Fortunately, the Golden Tube can be extensively modified. When that is accomplished, according to my associate who made direct comparisons in his own system, it will not only equal, but even exceed both the Cardinal and the Topaz amplifiers in purity, transparency, immediacy and naturalness.

To describe its greatest, and most important strength in the fewest words and in the most direct and simplest terms:

The Golden Tube 300B has the lowest "sound-floor" of any amplifier I have ever heard.

Unfortunately, it can't come even remotely close to any "normal" amp in sheer power, bass extension, control and impact.

It is still in this class only because of its (potential) state-of-the-art midrange and highs and its (relatively) very low price, $ 2,000 or less used. This means that it can exceed the performance of any amp I've ever heard in a "bi-amp" situation, If extra power is Not required. Virtually the entire insides must be gutted and then replaced with the finest quality parts available. The entire procedure and the better tubes will cost another $ 1,000, or more.*

Most important, it must be used with high sensitivity speakers (minimum 92db and preferably higher) with a benign (above 6 ohms) impedance. The size of the listening room may also become an important factor because of the limits of its power. The good news is: If you do find speakers that work with them, and I have, than virtually all other amplifiers will sound unsatisfying in comparison. This company is now, sadly, out of business, but the Reference designation stands.

The Golden Tube requires either the KR 300BXLS output tubes to reach its full potential.

* I am planning to describe the modification of this amplifier, in detail, within a new section on Modifications to be posted in the future. It should also provide a "blueprint" and general overview for modifying other tube amplifiers.

CAVEAT: In practical terms, this amplifier, and virtually all the other similar 300B designs of 7 or 8 watts, is an upper bass, midrange and tweeter amplifier only. Even then, it will still only work with certain, high-sensitivity and high-impedance designs. The only exception may be the Wavelength Cardinal, which has considerably lower measured bass response. This means, that with very few exceptions, another amplifier should be used for the frequencies below around 80 to 100 Hz. 'Reviewers', manufacturers and dealers who advise otherwise are doing a true disservice to audiophiles.

Below are now posted two pictures, outside and internally, of my personal Golden Tube 300B amplifiers, taken just before they were sold, which should assist a modifier.

GTA 300 B 001

GTA 300 B 003


According to my associate, this amplifier combines this second greatest overall amount of purity, delicacy, control, weight and authority of any amplifier he has ever heard in his 30+ year audio life (including the CAT JL-1 above). These are his own (anonymous) words, verbatim:

"The first amplifier that seems to do it all. The 'iron fist in a velvet glove'. 50 watts of 300B sound. That is, all the finesse, purity, transparency and low level detail retrieval combined with weight, impact, explosive dynamics and incredible bass. This amp does everything at the highest levels of excellence, Beautifully built, ( brushed aluminum face plate- finest trannies, choke filtered, Hovland caps, huge power supplies) and extremely reliable.

Output Tubes Ė 4 300Bs in a push-pull parallel configuration
Input- one 6SN7
Driver Ė one 6SN7
Rectifiers- pair of 5U4Gs

On sensitive speakers, this amplifier sounds gutsier and more dynamic than the ASL Hurricane, and destroys it in every other parameter of performance. The CA-339 will successfully drive virtually all but the most insane speaker loads (i.e. Thiels, Martin Logans, Avalons etc).

Might not equal a superb SE PX25 amp at its greatest strengths, or a SE 300B, but it comes frighteningly close. In all other areas, the CA-339 is an order of magnitude superior. $14,000 US/pr ainít cheap, but this is one of those rare instances in audio where it is actually worth it."

Personal Note- I haven't heard these amplifiers yet. Canary has another amplifier that is supposed to be even better; the Reference One Mono Blocks. None of us has heard them. They also make a number of preamplifiers, which we haven't heard. Unfortunately, they are all line-stages. No phono-stage is available according to their website (See Links File).

It must be stressed that these amplifiers have only been auditioned, as described above, on "easy" loads, meaning both high-sensitivity (above 90 dB) and high-impedance (above 6 ohms). Speakers that are insensitive, and/or with low/varying impedances, may not be suitable.

Further Notes- A reader has sent me three letters with his observations about them. I find his letters particularly relevant because he has other highly regarded amplifiers and he has compared them directly with the Canary. Here are his three letters, with only minor editing:

Letter 1- June 21, 2004

"I just saw an update on your web site about the Canary CA-339, and I thought I'd get my oar in on the subject.

I've owned a pair of (Coincident) Total Victories for about a year... As my aspirations for my system have grown, I've started looking for the perfect amps to drive them. So far I've gone through a Sugden Au51P, a KR 18 BSI, a pair of Coincident MP300Bs, a pair of Wavelength Tritons and a pair of deHavilland Aries 854s. About two and a half weeks ago... I took delivery of a pair of CA-339s.

I never imagined an amp could be so wonderful. Their sound is "complete", in every sense of the word. They have complete frequency response, complete dynamics, complete resolution, complete tonality and complete soundstaging. Their sound is completely natural in every regard. In fact, one of the things I've noticed about them is that the sound is so natural you don't even notice it, until you suddenly realize that what is making the music so breathtakingly real is the fact that the amps are doing everything right.

The source is an Audio Note 4.1x Balanced Signature DAC, and I'm currently using an Audion Premier two-box line stage... I have a CTC Blowtorch on order to replace the Audion, and I suspect that will tell the tale of the ultimate quality these amps are capable of.

...Anyway, at this point I completely agree with ...(the posted) assessment of the Canary amps - they are a match made in heaven with the Total Victories."

Letter 2- July 5, 2004

"I'm in the middle of re-tubing both the (deHavilland) 845s and the Canaries, and I'll provide more thorough impressions once all the tubes have arrived and settled in. Here's a preliminary look at where things sit right now:

The Canary CA-339s have their factory stock ElectroHarmonix 300B's, EH 5U4GBs and a set of black base RCA 6SN7GTBs. The deHavilland Aries 845Gs came with Russian 6AU5s, Russian 6SN7s, and Chinese 845s. In these configurations the Canaries were decisively superior in most regards to the 845 amps - better macro and micro dynamics, much better transparency, better frequency extension (especially in the bass), more precise imaging, a more open soundstage and more harmonic development.

I have since retubed the 845s with RCA black base 6SN7GTBs and KR 845s. It is now a much closer contest, and for the right listener the 845 is now the better amp. The dynamics of the Aries are now close to the Canary, the imaging is almost as good, the frequency extension in the treble is as good while in the bass it's not quite there yet. The soundstaging of the 845 is better than it was with the stock tubes, but still doesn't have the openness of the Canaries. In the area of harmonic development and density, however, the 845 amps are now decisively better than the Canaries. The sound is richer and fuller, with a very satisfying "big" tone. In addition, their sound is more relaxed. In comparison, the Canaries are revealed to have a slightly thinner tone, with a touch too much sparkle (verging on a bit of edge).

At the moment I'd characterize the 845 amps as "music-lovers' amps", while the Canaries are more "audiophile" amps. There's no question that the Canaries produce more venue information, develop a more explicit image and have more "balls". On the other hand, the Aries make listening to most classical, jazz and all folk music an unalloyed pleasure. With them I just sit down and sink into the music.

This is all subject to change over then next two weeks, though. I'll be completely retubing the Canaries with Philips ECG 5U4GBs, RCA red base 5692s and KR 300BXLS, which should dramatically change their sound. In addition, the KR 845s in the Aries are still brand new, and probably need about another 48 hours to really start showing their chops. I'll let you know how things go."

Letter 3- August 4, 2004

"I have some more observations on the Canary CA-339 following two months of break in and extensive listening.

I re-tubed them with KR 300BXLS power tubes and RCA 6SN7s. They love the KR tubes, and are now by a wide margin the best amps I've heard on the Total Victories. They achieve this through a combination of exceptional dynamics, total clarity, complete tonal neutrality, and a full realization of both the tonal and spatial properties of the recordings. They are completely at the service of the music, whether it be rock, jazz, blues, folk, classical of any sort from solo instrumentals to full orchestra, or anything else. They do both intimacy and scale with equal conviction. They sound utterly effortless. They impart a sense of realism to the recreated soundspace that is just plain spooky.

I've compared them to my deHavilland Aries 845G, which I have retubed with KR 845s. To be blunt, there is no contest. While the 845 is a very pleasant amp, it is obvious at all times that is is imposing its signature on the music. In contrast, listening to the CA-339 amounts to simply listening to the music.

While there are better amps out there for some applications, I can't imagine anything much better for use with the Total Victory or any other reasonably efficient, transparent speaker. My search for reference quality amplification is unequivocally over."

Personal Notes- Unfortunately, the KR 300BXLS is an expensive tube, but it appears to be a requirement if the owner wants to maximize the performance of the Canary amps. Considering the retail cost of the Canarys themselves, and the build quality and increased longevity of the KR tubes, I feel the extra cost is still reasonable and well warranted in the long run for the improvement the reader describes.

So far, it must be kept in mind that all the above accolades heaped on the Canary amps are by audiophiles who are using high-sensitivity speakers with a high impedance. I'm still waiting to hear some observations by owners of other types of speakers.

Based on the reader's second paragraph of his third letter, which is what my associate also told me in almost the same exact words, I can't remember the last time I've looked so forward to hearing an amplifier. Now I'll have to talk my associate into also getting those KR output tubes.

Most Recent Canary CA-339 News- One of my associates has informed me that the Canarys require high quality 300B output tubes to reach the performance that has been described previously, and which enabled them to be one of only 3 amplifiers within Class A. The lowest performing 300B tubes which are recommended are the Electro Harmonix Gold Grids. An alternative 300B, the Valve Arts, also available from Canary, is NOT recommended. My associate informed me that the Valve Arts seriously compromised the performance of the CA-339. On a similar note, the stock Chinese 6SN7s must also be changed to high quality NOS types, of which there are many choices. Without both of these tube optimizations, the CA-339 will not perform at the highest level, and is not a Reference. (2/05)

Most recent communication (3/05)- Below is some important information concerning these amplifiers, from "the horse's mouth" no less;

"I read your latest posting on our CA-339 and wanted to address the 300B position. A few customers have emailed and called me asking whether or not we supply output tubes with our amplifiers. On our website it clearly states that we do not supply them but apparently a little confusion exists.

For the record, all tubes (including output tubes) are supplied with our EL-34 based amps. With regard to the 300B amps, no output tubes are supplied and we neither recommend nor supply output tubes for any of our 300B amplifiers. As a convenience to our customers, we sell a number of 300B brands but do not endorse or recommend any of them."
Bill Feil
AudioFeil International

"Sound Products/Sound Solutions"
716-400-6177 Days/Evenings/Weekends

Personal Note- My associate highly recommends the Electro-Harmonix Gold Grids, especially for the money, while one reader, who has used a variety of 300Bs, feels that the KR300BXLS, which is much more expensive, is definitely superior to all the others he's heard, including the Gold Grids, and will elevate the amplifiers to a new performance level.

Further- I received this letter from Bill Feil, owner of AudioFeil International, who is the Canary distributor in October 2005. I feel this information will be important to the owners of these superb amplifiers. There's very little editing:

"...I want to call attention to both you and owners of the Canary CA-339, a moderately inexpensive (vis a vis very expensive premium 300B tubes) way to kick up the performance of these amps. Having just brought another pair of them into my showroom, I decided to leave the stock Electro Harmonix 300B as is. However, I installed a pair of 1960 Mullard CV 378 rectifiers and a pair of 1952 Sylvania 6SN7WGT in each amp. For less money than a pair of KR 300B's (these amps take 2 pair each keep in mind), the changes were breathtaking. Transients, soundstage, and articulation were noticeably improved. I thought your readers might be interested to know that, although these amps benefits from premium 300B tubes, these changes are a great cost effective compromise."


The Wytech is one of the finest overall amplifiers that we are aware of at this time. Its power rating appears "modest" (22 watts, 90 watts peak), and it does not break any new sonic grounds, but the "good news" is that this amplifier can virtually equal most amplifiers we know of in most areas of music reproduction.

To be specific: This means that it has much of the pure, natural, immediate and liquid qualities of the finest of the ultra low-power (under 10 watt) single-ended amplifiers, while still sounding as "gutsy", dynamic, and controlled as many more powerfully rated amps. Despite the standard "BS" regularly written in audio magazines, exceedingly few other amplifier have ever been able to legitimately make this claim in the past.

In short, this amplifier has excellent overall performance, especially at its price of $ 9,250, direct from the manufacturer. It is exceptionally well built and it is also ultra-quiet during operation.

Now for the "negatives":

1. This amplifier uses 1150 volts on the plate to get all its power from just one output tube (the main reason for its purity), so this isn't the amplifier to "play around and experiment with" inside.

In short: Touching the wrong spot would be the final mistake of that person's life.

2. This amplifier is dual-mono, but on just one chassis. It is very large and bulky, weighs around 120 lbs., looks industrial, and it is much more difficult to place (and hide) than mono amplifiers. (This is the reason that I was not able to use it in my own system.)

3. This amplifier will not sound as described with the many low-sensitivity and low-impedance speaker models that are on the current market. This is just one more good reason to avoid those frustrating and self-defeating designs.

4. These amplifiers are custom made, one at a time (by owner and designer Roger Hebert), so there may be a waiting period for them. As far as I've been told, only the earlier (and inferior) model, using 845 output tubes, was ever sold "retail".

5. These amplifiers can be improved with better tubes, particularly the 6SN7 input tube and the 6BX7 driver tube. The 572 output tubes have no superior replacements at this time.

MONOS- There are also Wytech's own mono amplifiers, the 572M, which are a unique single-ended design using two 572 output tubes and two output transformers per channel, to minimize inductance.

They are 45 watts per channel and are $ 18,500 for a pair. None of us have heard them at this time. Other listeners, who have made the comparison, have reported mixed messages; some of them preferring the monos, and others describing the only advantage being the increased power. Some have even mentioned that there was an actual sonic (along with the obvious theoretical) disadvantage caused by configuring the two output transformers in "parallel" or in "series", depending on the speaker impedance.

One of us has compared two of the stereo amplifiers to just one. Despite the fact that the two stereo amplifiers had the advantages of both biamping and total mono separation, there was virtually no sonic improvement. This means that the stereo version sounds the same as the mono versions of the same amplifier. That is quite an accomplishment.

CAVEAT: There is actually more than one version of the Topaz amplifier from this company. The "original" Topaz used the 845/211 output tube. That is the model to avoid. It was still "excellent", but nothing "special". I know, I heard it in my own system. For some inexplicable reason, the manufacturer decided not to change its model number when he changed its design.

The current models only use the 572 output tube. This is the only model that is a Reference. Accordingly, it is safest to order a brand new amplifier and simply ignore any used models that come up for sale. This company also makes a "budget" amplifier called the Onyx, which also has decent sonics and good build quality, but it is also nothing "special".

FURTHER- I recently received news from a reader about two interesting components from Wyetech Labs, who have one of the finest audio "track records" in the last decade. One of them is new, while the other is an update of its most famous model. Here's the letter, with minor editing:

"Maybe you already know this, but there is a "new" amplifier from Wyetech Labs. It is the Sapphire 300B monoblocs, (Parallel) SET based on 300B tubes. Here's the link:

Also, there is a new version... of the Topaz, the Topaz 211C. The 572 tubes have been replaced by a new brand of 211 tubes."

Personal Observation-First Viva, and now Wyetech, has replaced its flagship model using 572 DHT tubes with a 211 DHT. I was under the impression that the 572 was the superior tube with more potential. So what's up? Well, readers should be made aware that the Svetlana 572 tube is now DISCONTINUED, and the remaining stock is both drying up and now rising in price. I think these two manufacturers are simply reacting to the reality of what is practical to build today. (12/05)


This amplifier is similar in design and competitive with the Topaz. It is made by the Italian manufacturer VIVA. The model is called the Aurora. It also uses a single 572 output tube, but these are "all-out" mono blocks, using in-house output transformers and they have the further advantage of using another 572 as the driver tube. Even more surprisingly, two more 572s are used as rectifiers, but that can be a mixed blessing.

There are some "downsides". The power supply is not as large and sophisticated, and the passive parts don't equal the quality of those within the Topaz. Both of those disadvantages can be addressed with various modifications, which should not be that difficult to do within such a large amplifier.

These amps are custom made only, and cost $ 22,000 a pair. This means that they will probably never be a Reference new, because the price differential with the competing Topaz is just too large. A used pair, with modifications, is another matter, because these amplifiers sell for half-price or less on the second-hand market. Their cosmetics are stunning.

VIVA now makes a very similar amplifier, using the more powerful, but usually less accurate and pure, 845 output tube. It is still called the Aurora, believe it or not. (Is there a fashionable trend to confuse potential purchasers?) An associate and I heard this new 845 amplifier at the 2004 CES and were very impressed with it, so this model may be something to look into.

Auditions- We auditioned the 572 Vivas a number of times with mixed results.

First Audition

I auditioned the Vivas (stock) on my (now former) store system (CD based and with Coincident Super Eclipses) and on my own system (analog, and with the Ars Acoustica System Max).

On the store system, the sound was the best I ever heard with it, by far. Several customers, who were very familiar with that system, agreed with me. In fact, one of them, a very critical listener, said that it was the first time he had ever enjoyed the Super Eclipses. The sound was far superior, overall, than with the Manley Retros or the Altec/Tutay. It was incredibly natural and full bodied. It retrieved a considerable amount of musical information, which was almost always lost with other amplifiers.

I, and every other person who heard this system, couldn't have been more impressed. However,...

Second Audition

I then put the Vivas in my own system. First on the subwoofer, where it didn't have the best impact I have had, but it was superior in the most important areas; harmonic structure and the retrieval of low-level information; ambience, decays, space etc. (The Vivas on the bottom, and the Golden Tubes on top, was the best sound I ever experienced at that time. Every person who heard this combination, agreed with me.)

Next, I connected them to the main speakers, where it competed with the Golden Tube 300B mono amplifiers (above), which are highly modified. This time they didn't have the purity, immediacy, transparency and the ultra low sound-floor of the Golden Tubes (neither does any other amplifier I have ever heard). The Vivas had more of an "electronic sound", though they still demonstrated their previously described strengths. I, and another of my associates, preferred the Golden Tubes. One of my customers then purchased the Viva amplifiers just before I moved to Florida.

Prior to this...

Another one of my associates had the same Viva amplifiers at his house and also compared them to the Altecs, the Manleys, the Golden Tubes and the Topaz. He preferred the Vivas to the Altecs and Manleys, just as we did and for the same reasons. He also preferred the Golden Tubes to the Vivas in the midrange and highs, again agreeing with my conclusions. As for the Topaz...

He preferred the Topaz overall. He felt the Topaz equaled the Vivas in its strengths, but had more dynamic power and was also noticeably superior at the frequency extremes. He was so impressed, that he ended up purchasing the Topaz.

I then heard his system with the Topaz, twice, but the sound was not as good, overall, as what I heard with the Vivas at my place, though I agreed with him that the Topaz had better frequency extremes and more dynamic power. (Two of my other associates agreed with my assessment of his system compared to the system in my store with the Vivas and Super Eclipse.) He explained that the problems we all heard were caused by his speakers (Coincident Victory and Total Victory) not being broken in yet. So this is my problem.

If I take this associate at his word, where do I place the Viva? Probably "Class B", with a caveat that it is a Reference only at a used price, since the Topaz is much less expensive new, and it is better.

However, what if he is wrong? Because he couldn't hear the strengths of the Viva through his speakers, which were not yet broken-in, or for some other reason. Also, the Vivas have room for serious improvements, while the other Class A amplifiers do not. Additionally, the Vivas are noticeably superior to even the finest of the current Class B models.

The Temporary Solution: I am going to place the Viva (used only) in Class B. I know they are at least worthy of that designation. They may be a Class A amplifier, but I would like some confirmation, based on a thorough audition. So far, they came in second to the Golden Tubes in my system, and, according to my trusted associate, second to the Topaz in his system.

They will have to be superior, or at least comparable, to one of these two "Kings" in a serious "shoot-out" before they, or any other low to medium power amplifier, can join this very exclusive club. (See "The Reference Policy" within The Reference Components "Introduction".)

MANLEY 300B RETROS/NEO-CLASSIC (Used or "On Sale" Only)

The Retro/Neo are superb, but do not have the ultimate transparency, naturalness and purity that the finest single-ended amplifiers possess; like the Golden Tube (modified) or the Wavelength Cardinal. However, their bass reproduction is superior to those simpler designs and they will work with a larger variety of speakers.

There are two requirements for optimization; the speakers must be sensitive (90db or higher), and also have a benign impedance (minimum 6 ohms, preferably above 8 ohms).

These are the amplifiers to consider if you still require more power than the 300B Single-Ended amplifiers (8 watts) can give you. Unfortunately, the Neos have a retail cost of $7,200 a pair, which is only $ 1,700 less than the superior Topaz. That is the reason why they are a Reference "Used" or "On Sale" only. The Topaz is still easily worth the extra $ 1,700, and more. (However, don't forget the Topaz's problem with size and placement.)

The Neos are mono, with two 300B output tubes per channel. They are very versatile: They can be switched from single-ended (12 watts) to push-pull (24 watts). They also have adjustable feedback, from 0 to 10db in 1db steps. They even have two inputs; a standard RCA and the other balanced.

They easily outperform all the Jadis single-ended designs that cost far more, and are even better than the Original ($14,000) Topaz. I sold and lived with the Retros, though I haven't heard the latest Neos myself, but one of my associates has, and in depth.

The most serious competition for these amps are the most recent (and now final) version of the Coincident 300B mono blocks (please see below), which have almost the exact same design, cost far less, and, according to at least one reader, even outperform the Neos. (I obviously never made a direct comparison myself, but I've been overall more impressed with the Coincident models than a highly modified pair of Retros. This was because they sounded closer to my Golden Tube 300B amps than the Manelys.)

The Retros were the previous model, now discontinued, and are very similar in sound and design. They had a retail price of $ 5,500 a pair. They were not quite as well built, and their sonics are not the equal of the Neos, but they are very close. (In fact, I now understand that some listeners prefer the more immediate sonics of the Retros.) The Retros are still a Reference because of their overall performance and excellent value for the money. The Retro must be used with the KR 300BXLS output tube, or else the amplifier will have both reliability problems and less than optimum sonics. They are expensive, but worth it. There is also a "bonus"; the Retro sounds its best with this tube.

The newer Manley NEO design is not as hard on its output tubes, so virtually any 300B will work with it, but the KR is still an excellent choice because of its sonics. (7/03)


This "vintage" Altec is a fantastic amplifier. It could be the "dream amplifier" for many audiophiles. I didn't list it initially because of the many hurdles to get an optimized working pair, and the potential danger in using them. Let's discuss the sonics first, and then tackle the remaining issues.

This amplifier, after it is fully modified, can compete with virtually any push-pull amplifier in the world. It uses only two 811A direct heated triode output tubes, but it can still generate over 150 watts per channel. It has a very high quality power supply with chokes, tube rectification, separate input and output supplies etc. The end result is a combination of tremendous power along with a lot, but not all, of the purity and transparency of the single-ended designs.

Other "high-power" tube amplifiers, that use multiple output tubes (8, 12, 16, or 20 per channel-especially pentodes) to create their power, can not compete with this simpler (and much less expensive) design. As usual, it is at its best with high-impedance loads, but it can still sound excellent in normal impedance loads as well, though it is not a good match with very low impedances.

Now for the inevitable "hurdles":

1. The original Altec 1570 series of amplifiers were designed and built for "commercial" and "industrial" applications; The U.S. military, sports stadiums, factories, auditoriums etc. They are very reliable of course, and are also downright ugly in appearance. There may have been many made 50+ years ago, but now they are difficult to find. Their sonics, stock, are simply horrible. They sound "dirty" and have no bass. So they must also be modified.

2. There are very few people who can modify these amplifiers. The person who had, by far, the most experience, and has achieved the finest results we've heard, was (the now late) Tom Tutay, a talented engineer who lived and worked in Florida. However, there may now be another technician who also has the required knowledge and skills. According to some posts I read on Audiogon, the modifications performed by John Tucker (Exempler Audio) may even be superior to those by Tutay.

So after a pair of these were found in good condition, they were sent to Tutay for his (very extensive) update. There were some options, but the standard modification cost at least $ 3,000. Considering the enormous amount of work involved, that was a very fair price. The total cost, including the amplifiers themselves and all the shipping, was in the $ 5,000 range, unless you "scored" on the Altecs.

To put things in perspective, if such an amplifier were built in North America and marketed today, it would sell for a minimum of $ 15,000 and much more likely $ 20,000 or more.

3. After all the above has been done, there is another important issue to ponder. The reason why these amplifiers can generate so much power with only two output tubes is simple; there is more than 900 volts DC on the plates. This voltage itself comes from the rare, high voltage power transformer, which has somewhat louder than average "mechanical noise". (The extra expense and difficulty in finding and utilizing very high voltage components is the primary reason why contemporary amplifier manufacturers haven't just copied this design.)

Unfortunately, there is a potential danger to this design. The 811A output tube receives this high voltage from an (easily accessible) cap on the top of the tube, and not from the usual, inaccessible tube pins within the chassis. This means that anyone (or anything) who removes this cap while the amplifier is "on", or even "off" for a short period of time, and touches the internal metal part, can be electrocuted. I realize only a reckless fool or someone incredibly ignorant would do this, but I felt it should still be mentioned.

The Altec came with a perforated, protective cover which made it impossible to reach the cap, but it may be missing, and some people may prefer not to use it because the 811A output tubes look "cool" when they are "on" and all "lit up". This is highly unadvisable.

My advice is to do whatever it takes to make these plate caps inaccessible to others; a replacement cover, screen etc. Don't worry about "ruining" the appearance of this amplifier, it can't be made any worse than it already is (see pictures of the Altec below). Once that is done, this amplifier is as safe as any other tube amplifier, and very reliable.

One final concern also deals with the Altec's very high voltage. A reader has informed me that an electronics designer warned him that the amplifier can "emit high radiation levels".

The designer's advice to an Altec owner is simple: "He will want to distance himself as much as possible from those amps..." This advice is also applicable with any other electronic device using high voltages; such as televisions, some older computer monitors and even "typical" tube amplifiers etc., so this information doesn't compromise the Altec 1570's Reference designation except in very highly unusual circumstances. (The now late) Tom Tutay, the modification expert and engineer, also feels the amplifier is "very safe". (20 or more of these Altec amplifiers were used in the Astrodome and they were on 24 hours a day. The engineers who worked in near proximity never had any problems with them.)

Further (2/05)- A reader sent me some information and observations concerning these two very different amplifiers. Here they are, slightly edited;

"Did you know the Altec 1570 is an ALL class B amplifier;-) What a sweetheart. Wish I bought a pair years ago. The first time I heard them (was) on a pair of MBL 101's. I couldn't believe it.

Also the CAT JL2 is definitely better than the JL1 with one reserve, the bass is better on the JL1. For the bass, you move up to the JL3."

Personal Notes- I had no idea the Altecs could drive the MBLs. All I can add is, despite my best efforts, I haven't found a better bass amp for my own system, at least so far. I do have a new "contender" in the works. If everything goes to plan, I'll compare them this Fall, after the Hurricane season.

FURTHER (11/05)- I received some important information from an "associate" concerning this excellent amplifier (which I still use myself as a subwoofer amp). According to my associate, Magnequest is now building an updated version of the Altec's output and interstage transformers.

The output transformer is the real news, since it will be flat to 20 Hz, and will even have a 4 ohm tap. This is excellent news for people who will use the Altec with full-range speakers and/or low impedance loads (like me!). I'll post more information when I find it. I checked out Magnequest's website myself, but I found nothing on these transformers. Finally, they are supposed to cost $ 200 each, which sounds reasonable to me. I don't know the cost of the interstage transformers, or any sonic or practical advantages they have over the "originals".


A reader just sent some information on how to further improve this already unique and excellent amplifier. It is simply a tube replacement, but this time it's not just the brand of the tubes, but the actual model of the (output) tubes that are changed. Here's the letter with some editing:

"...the true copy of the ("Taylor") 572b, made by the Chinese (Penta Labs), not Svetlana, are direct drop-ins for the 811A. The bottle is 'ST', and not straight walled like an 845/211 transmitter triode. Tom Tutay said to use it and wrote this in his hand written manual which also gave the general history of the Altec amp along with upgrades, etc.

Biasing the tube is easy and a direct drop in for the vintage 811A...All we know is that after all the tubes were dialed in, it was like going from a weak V-8 to a big V-12, with lots of head room or reserve just setting there. We liked the change for its bottom end and over all extension."

Personal Notes-This may be really good news. I will verify all of this with Tom Tutay myself, and then try this "modification" on my own Altecs to see what results I get. I only use the Altecs with my system's woofers, but the improvements, especially in the entire bass frequency range, should still be easily noticeable if this reader is correct.

Caution- Audiophiles who already own the Altecs should NOT simply replace their currrent tubes with the 572B. Be patient until you find out exactly which brand(s) of 572B is/are recommended and the correct biasing for that tube. We're talking 900 volts here, so don't do anything until you know for certain that it's safe.


I recently asked Tom Tutay, the person most intimately familiar with this amplifier, about switching the output tubes from the stock 811A to the 572B. Tutay informed me that it's no problem to make the switch; the amplifier just has to be re-biased, as with every change of the output tubes. The actual bias, and everything else, remains the same.

Tutay also informed me that he felt the amplifier's resulting sonics, with the 572B, were "different", and not necesssarily "better", depending on personal priorities. Still, considering the relative ease and small monetary investment involved, I feel the enthusiasts of this amplifier should try it out for themselves if possible. (But please, never go inside the 1570B unless you know what you're doing- The potentially lethal 900 volts remain on the plate.)


I received further information about the 572B output tubes for this amplifier, which can be replacements for the stock 811A. Here it is, with slight editing (My Bold):

"(I) wanted to respond about the current production 572b. There is an eBay tube seller that offers a year warranty, fully understanding they may be back-up tubes, and not be used imediately. Penta and all the rest only offer a 30 day warranty from the day of purchase. BTW, all the 572b tubes are made at one plant in China, but some sellers will take the time to burn them in and really test them because short-wave radios put a lot more current on the tube than audio use does.

The eBay seller is: k5svc, and has a store with tons of parts and tubes for short wave radio people. His email address is: "

Altec 1

Altec 2

Altec 3

Altec 4


The "Hurricane" is a large, heavy (65 lbs) and powerful (200 watts per channel) mono power amplifier built in China. It uses 8 KT-88 and 3 6SN7 tubes per channel.

It is a "push-pull, ultralinear design with point-to-point wiring (no circuit boards), two power transformers (one 'push' and one 'pull') and 0 NFB". The latest models use special oil and paper capacitors (more on this below). The biasing is very easy with a large LED readout. Amazingly, the price is $ 4,400 for the pair! (Compare that price to equivalent models from Audio Research, Conrad Johnson, McIntosh, Jadis, VAC, Manley, VTL etc.)

This amplifier has been extensively auditioned by the same associate who owned the rare and expensive CAT JL-1 mono blocks, now in "Class A". A comparison of the two models was made on his own (very high resolution) system. The results are...

The CAT still has some advantages, but my associate also claims that the Hurricane is close enough to be "competitive", and it is only around 1/5th the cost of the CAT. He was impressed enough to purchase a pair.

Paraphrasing his description of them: "Tremendous dynamic range and control, huge and focused soundstage, along with a surprisingly natural and refined sound, especially considering its size and power. A breakthrough for the money."

I have also heard them myself, on my associate's system, and can now verify his above description. In addition, I was able to observe that it still obscures some "inner, fine detail" and loses other important musical ("low-level") information, which is the strength of the finest single-ended designs I've auditioned. Its "sound-floor" is also very low for a high-power tube amplifier, but it's still higher than the best of the simpler designs.

Three Different Models

Since our initial Reference designation of this amplifier in May 2002, and my later audition of them in September 2002, another version came out with oil and paper coupling capacitors, which are made by the same factory that designs and manufactures the Hurricane. (There were a few other minor changes, but they are sonically insignificant.) My associate had a pair of this new model and has made extensive comparisons with the original amplifier.

(The "original" version of the Hurricane used metallized MIT polypropylene capacitors. These are best described as "utilitarian" and are both the cheapest and worst performing caps within the entire MIT line-up. Their film and foil polypropylene and (top-of-the-line) polystyrene are both much superior. I know this for a fact, because I have more than a decade worth of experience with all of their capacitors, including within my own systems.)

To my associate's surprise, he much preferred the oil and paper capacitors, despite their generic reputation for normally being "soft, weak at the extremes, blunted, veiled etc". He informed me that these new capacitors were either equal or noticeably superior in every area of music reproduction to the budget MIT equivalents. The overall improvements he heard are one of the reasons why this amplifier was originally moved up to this higher class (the other reason is that I was initially cautious because of our previously unsatisfactory experiences with some other components manufactured by this company).

TAS Enters

Meanwhile, The Absolute Sound (TAS) (Harry Pearson no less) gave this amplifier a rave review, calling it, in effect, "the best amplifier in the world". They then went on to badmouth the new oil and paper caps. They are wrong on both counts.*

While this amplifier is most likely the best value for a high-power amplifier now available, which is why I listed it in the first place, it does not equal the better single-ended-triode designs in their important sonic/musical strengths. I know this for certain, because I compared this amplifier with a superb, but not "state of the art", SET amplifier myself (the Coincident MP 300B-see below). My associate also felt that the Tenor 15 Wp was superior in its primary sonic strengths, and he now prefers the Antique Sound Lab's own AQ1009 in overall performance (see below).

Yes, this model has its own important sonic advantages over the best of the SETs, which just simply means that it is impossible for there to be a single "best amplifier in the world" (at least as of today).

As for the capacitor issue, I trust my associate's hearing and competence much more than I trust Harry ("120 dB") Pearson. The fact that Pearson can't even easily hear the sonic downsides of the Hurricane is alone enough to seriously question his present hearing ability. Fortunately, the distributor and manufacturer appear to have solved this issue themselves. (See below)

* While I have a serious disagreement with Harry Pearson as to the Hurricane's ultimate merit, I do give "HP" (and TAS) credit for finally bringing recognition to this amplifier. Recognizing "unknowns" and "little-guys" may have been typical behavior 20 years ago, but that is no longer the case today for the the major magazines.

Further TAS Controversy- In the "Reviewing the Reviewers" file, within The Absolute Sound sub-file, please read the correspondence between myself and the late Randy Tomlinson for more information, opinions and experiences concerning this amplifier and compatible speakers etc. (3/04)

More Information

My associate has now extensively auditioned the latest (March 2003) version of the Hurricane. It has a "Triode switch" plus it uses new, multi-layer, paper and oil capacitors, which cost 20 times what the older MIT capacitors costs. He has informed me that (when it's operating in triode) this new Hurricane noticeably outperforms the two earlier versions. He claims it is superior in virtually every sonic parameter, including dynamic intensity, transparency and purity.

These significant improvements are the reason why the Hurricane has, once again, moved up in these listings. However, it still does NOT equal the finest SET (or OTL) amplifiers in their greatest strengths. Of course, many, if not most, listeners may still prefer the Hurricane's own strengths. (In fact, a number of listeners preferred the Hurricane to the Wytech Topaz in a recent shootout, even though they acknowledged the Topaz's superiority in its sonic "upsides".)

Output Tubes

A few of my associates have had an opportunity to try out different output tubes. They prefer the Svetlana 6550C. The output tubes that come with the Hurricane, the Valve Art KT-88, are warmer in character, which many listeners may prefer, but lack some detail, purity and transparency. Actually, changing the 6SN7 input tubes will probably make more of a difference. NOS tubes from the World War II era are preferable. Unfortunately they are expensive, $ 50 or more, but they last a long time.

Bottom Line- Readers must demand only the latest model of the Hurricane, which includes the Triode switch and the latest multilayer oil and paper capacitors..

Further Listening- In early June 2003, I heard the absolute latest version, with the triode switch, for six straight hours, with a system, room and software (all LPs) that I am very familiar with. The results actually surprised me.

To put this bluntly; the more I (actually we) hear this amplifier, the less I'm impressed with it. It is a "breakthrough" of sorts. For an amplifier using 8 power tubes per channel, 4 "push" and 4 "pull", it has amazing performance, especially for the money. It is relatively clean, transparent, dynamic, neutral, "big sounding" and has excellent frequency extremes. It is competitive with, or better than, any other "big amplifier" I know, and at any price.

The Hurricane's problems become evident when you begin to compare it with "small amplifiers". It just doesn't have the immediacy, transparency, inner detail, purity and low sound-floor of the finest low and medium powered amplifiers I've heard. This is easily noticeable to any experienced listener.

Audiophiles who don't require the power of the Hurricane should seriously consider low-powered alternatives, but for all those many audiophiles who do need the power (50 watts or more), the Hurricane is the best amplifier news I can remember in my now long audio career. That is why it will remain in Upper Class B.

Finally, the Hurricane sounds much better when it's operating in the Triode mode. There is really no comparison. I write this only because I was told that some owners actually prefer listening in the standard Pentode model. This preference is a mystery to me, so it's safe to say that I don't share much in common with these listeners. (7/03)

Some Readers Weighs In

Further- Here is a short note from a reader who owns a pair and who shared some of his recent experiences:

"You're right, triode is the only way to listen to the Hurricanes. Also, it helps to substitute Sylvania 6SN7 GTBs for the Chinese tubes. I also tried RCA red base 5692s, but I didn't care for them. In the Hurricanes the sound became darker with less detail. I was surprised.

One other note about the Hurricane's tubes. I found that changing to the Sylvanias sharpened up detail and definition enough to make up for the warmth of the KT-88s. I tried the Svetlana 6550Cs but found when used with the Sylvania 6SN7 GTBs, they made the midrange too forward, so much so that the vocals and instruments, such as tenor sax, seemed detached from the rest of the music. (In my system.)" (9/03)

"I am your reader with a pair of Hurricanes with Sylvania driver tubes. Well, that was then. Now I've found a combination of V-11 (driver) Tung Sol "Black glass, Round plate" 6SN7GT/VT-231,.... V-10 (driver) Sylvania "Stagger plate" 6SN7GT (both 1945 Vintage)... and in V-9 position (splitter) an RCA "Gray glass" VT-231 is pure magic. While I am sure there are other combinations that will yield good results, I now have tried 12 sets of vintage 6SN7 types in various combinations and have concluded that this combo is the best I have heard. Mixing tube types enhance the good properties of each tube type while minimizing their week points."(1/04)

Hurricanes and Electrostatics-First Take

This letter is from a reader who has the latest Hurricane and is using it on an electrostatic speaker. These are his edited observations:

"I have purchased the new Hurricanes and use Acoustats [heavily modified 2+2 with Medalion transformers, plus after market resistors and caps, impedance down at 3.5 ohm at 20 Hz, rising to 6 ohm, then down to 2.5 ohm at 20kHz]. ...I have had them for only one month, so what is still in store I am not sure; first impressions as follows: I noticed the bass to be extended although somewhat loose, the cellos are warm and full, the guitars are tactile and sing, the violins tend to lack air or extension, the pianos have good weight but again the high notes lack the last bit of clarity (that pearly ring of the upper mid and high open strings), the organs sing but are a little overfull in the bass. Power and impact are impressive." (5/04)

Note- Since this reader is using an unusual load for the Hurricanes, I asked him to continue to forward his observations which will also be posted here.

Caveat- There is also a 100 watt version of this amplifier, but my associate informs me that "it has none of the magic of the Hurricane". This is another example (and important reminder) of this company's inconsistency in performance.

Hurricane Mk. II and Summary of Above

There is now a Mk. II version of the Hurricane, which has two chassis. None of us has heard it yet, but it must be assumed that it is superior, in some fashion, to the "original" Hurricane, discussed at great length above. Of course, the introduction of the II will inevitably mean that the original model will be discounted. This then provides a great opportunity for those waiting to buy a Hurricane at a great price.

In fact, the original Hurricane, when purchased used at a good price, may be the best value of any amplifier ever made, considering the three conflicting goals: highest power, highest performance and lowest price. I know of no other amplifier that would score as high as a pair of used Hurricane when attempting to optimize these three goals at the same time.


This is a report from some of my associates.

First the facts: It is a push-pull amplifier using (2) 845 output tubes. The other tubes are (per channel) two 12AU7 and two EL-34. You can replace the EL-34s with KT-66, but the sonics will be degraded. There are five (5) transformers per channel! (Output, high voltage power, low voltage power, input and coupling.) The price is (a very reasonable) $ 5,300 for the pair.

The early models, stock, were superb in some areas, but "somewhat lean and not fully, harmonically fleshed out". They also used the same cheap MIT capacitors that the original Hurricane used. My associate replaced these MITs with the latest oil capacitors, built by Antique Sound Labs, and also used in the latest Hurricane. According to him; "big difference". The sound was fuller, purer, more detailed and with better bass.

This amplifier is only a Reference if the new oil capacitors are used. (The latest models may already include these oil caps, see below.)

My associate also made some direct comparisons, after replacing the capacitors, to two of the highest rated amplifiers on this website; the latest Hurricane and the Wytech Topaz, which is currently in Class A. He also had the help of several friends for verification. The comparisons were made on high efficiency speakers, playing at both high and low volumes. The results were:

AQ1009 Vs. Hurricane- The Hurricane had slight advantages in power, dynamics and bass, but they were not significant. The AQ1009 was noticeably purer, more detailed and more transparent. Almost everyone* preferred the AQ1009.

AQ1009 Vs. Topaz- This time the results were exactly the opposite. The amplifiers were "similar" with "undemanding" music, with the Topaz now having a slight advantage in purity and transparency etc., but the AQ1009 was noticeably more dynamic and also had superior bass. This was especially noticeably with "demanding" music. This was a trade-off of giving up a little, and getting back a lot. Everyone preferred the AQ1009. The AQ1009s are also just half the price of the Topaz, and are real mono blocks.

*Further- Since that initial comparison, one listener, my associate, says he still prefers the Hurricane overall. It is his favorite amplifier, with the possible exception of the CAT JL-1, which he hasn't heard for a while, and is not available for a direct comparison.

Along with the mentioned advantages in dynamics and bass, he feels the Hurricane has more body and sounds more "right" than the AQ1009. He says he just "enjoys" listening to Hurricane more than the AQ1009. He stresses this is only true of the latest Hurricane with the latest oil and paper capacitors. (5/03)

Future- The above is based on only a few intense weeks of testing. More listening and comparisons are scheduled. Meanwhile, I was told that the latest models of the AQ1009 will contain the new oil capacitors. If true, no modifications will then be necessary.

More than a year ago, I forecast the future domination of Asian tube amplifiers within the North American audiophile community. The future may have arrived earlier than I thought, if not in market share as of yet, certainly in performance, especially for the money.

Tube Rolling- A reader has written to me since the above has been posted. He has more experience with the AQ1009 than anyone I know. This is what he informed me:

"As you may remember - I have these amps--the best tubes I have found are; the KR845---E80cc for 12AU7---and National Union (first choice) or Western Electric 350b. These are by far the best amps I have heard. The inputs/outputs need to be changed (to Cardas). I also changed the internal wire to JenaLabs. All the tubes, wire, connectors have been Cryo treated by Jenalabs ( With the changes stated above, better amps by 50%..........."

This same reader later added this information concerning the Western Electric 350b tube and the bias; "they can be dropped in---bias should be set 350 max..I run at 300-325" (7/03)

Further- After a request, a reader provided his (edited) observations concerning some of the finest amplifiers ever made; the ASL Hurricane, the ASL 1009 and the Altec 1570B (modified):

"...The Altec 1570B is maybe slightly leaner, the Hurricane more full-bodied. A slight edge in clarity might go to the Altec, and they are about even on power- both are extremely ballsy. Reliability DEFINITELY goes to the Altecs- these things have been champs in my system (I would NOT have sold these had I not needed to finance the ASL 1009s, and in some ways I still prefer the Altecs- an interesting toss-up...). Further on reliability, I am learning of some problems with the Hurricanes (blown resistors, etc.), and as compared to the Altecs, further issues also due to all those extra tubes. The ASL 1009s have been FAULTLESS however- in my opinion THEY are the champs of the ASL lineup- improved clarity and low-level detail over the Altecs, albeit with a smaller power output. Ultimately, if cash had not been needed for the Total Victorys in my large ~20' x 20' main room, I would be putting the ASL 60-watt 1009s on top, and the Altecs (or Hurricanes) on the bass in a bi-amp setup, and I would have a second, smaller, den-type listening room with the smaller Victorys and a pair of 12-watt Wavelength Cardinal X1s- THIS would be my ultimate setup..."

Extra- There is another amplifier from Antique Sounds Labs that uses ONE 845 output tube per channel, making is a true SET. It is the AQ1006. My associate has auditioned it extensively. The result: It is not that good. The problem is that it is not an "all-out" amplifier like the AQ1009 or the Hurricane, which both have large, stiff power supplies. Avoid it for now. (5/03)


I used to be a dealer for this company. This amplifier, and a simpler stereo integrated version of it, came out the year I left the retail business (2001), so I never had a chance to purchase one for the store or even audition it. The proprietor (not surprisingly) raved about it, and I heard other good things from a number of owners, some who had wide experience with amplifiers, but I wasn't in a position to do anything more than mention its "potential" to the readers of this website.

I finally had a chance to hear these amplifiers on a system I was familiar with, for a period that allowed me to hear it "in-depth", and also afforded me an opportunity to compare it with some of the other amplifiers on this list, including the Hurricane. In short, this is a superb amplifier, and very similar in basic design and performance to the Manley Retros/Neos.

It has exceptional low-level information and purity, noticeably more than the Hurricane, though it's not equal to what I've heard with the Golden Tube 300B, which is in Class A of course. It has excellent dynamic qualities, especially for its power rating, and unexpectedly tight and impactful bass, but the speaker I heard it with (the Coincident Victory) is an "easy load", so speaker choice is critical with this design. Of course, the Hurricane (and even the Topaz) is considerably more dynamic, "controlled" and impactful at higher volumes, and can be used with virtually any speaker.

This amplifier is very easy to bias and is very well built for the money. I think it is manufactured by the same company in China that (ironically) makes the Hurricane. In effect, it is an enhanced version of the Antique Sound Labs 300B amplifier.

2003 Update- I heard the most recent version of this amplifier when I visited Toronto in October 2003. I was very impressed. It was a significant enhancement over the earlier version, which was already excellent. The most obvious sonic improvements were in the areas of immediacy, transparency and purity. There was still a problem in the bass frequencies, which was blamed on the output tubes being used at the time.

The owner of Coincident, Israel Blume, informed me that he was now using superior coupling capacitors (oil and paper), input transformers and output transformers. These amplifiers should still be used only with high sensitivity and high impedance speakers, like most of the models from Coincident themselves. That's the only type of speakers I have auditioned them with.

While there, I also heard these amplifiers with very expensive ($ 125 each) and rare NOS 6SN7 input tubes. The improvement was only modest, so the stock (Chinese) tubes must be excellent. The output tubes were a different story. Blume first offered an optional update, but has since replaced the original tubes with the latest Electro-Harmonix 300B. The new retail price for a pair is now $ 4,000.


I made my semi-annual visit to Toronto, where I lived and worked for more than 30 years. I was there 10 days for mainly business reasons, but I did spend one entire day at an associate's house, where I had a lengthy, fascinating and highly productive listening session. I actually had some unprecedented experiences. One of these experiences, my/our observations and the final results and conclusions are discussed below.

An Important Comparison- Stromberg-Carlson AP 55 Vs. Coincident MP 300B

Prologue- I've heard the Coincident amplifiers a number of times now, at great lengths and with both equipment and software I am intimately familiar with. The last time I heard them, in October 2003, they were simply superb, though they had problems in the bass, due to (according to the importer, Israel Blume) their (then) stock 300B output tubes. This time I heard them with the (now stock) Electro Harmonic Gold Grid 300B. There's no question they're a noticeable improvement over the former 300Bs. The bass is better defined, deeper, cleaner and with more impact and punch. There may be other improvements in the mids and highs, as Blume claims, but I couldn't confirm them in these limited circumstances.

I made this comparison myself. After a proper (30 minute) warmup, it soon became obvious that the MP 300B was to the AP 55 as the AP 55 was to the (described and remembered) Hurricane. (See Vintage Amplifier File for description.) In short, the MP 300B was cleaner, more transparent, more immediate, and less electronic than the AP 55. In turn, the AP 55 was still a little better in the bass and dynamically. This was all easily noticeable, but a particular comparison of two records demonstrated the sonic superiority of the MP 300B in a manner I've never experienced before.

An Uniquely Important LP Comparison

The two LPs were:
1. John Klemmer-Touch-Mobile Fidelity, and
2. Dom Um Romao-Saudades-Water Lily.

It must be first emphasized that neither of these LPs is "demanding", in the sense that a Mahler symphony would be, since they're both "light Jazz", so the difference in power of the two amps was irrelevant. Also, I didn't intend to compare the recording quality of these two records, it just ended up happening because of the totally unexpected initial results. It all started innocently...

Both records sounded predictably excellent on the Stromberg-Carlsons, but I was immediately faced with a serious dilemma because, in a number of ways, the Klemmer/MFSL sounded better than the Romao/WL. This should not have been possible. Why? This was my dilemma:

How could the Klemmer LP, which I had placed in "The Honorable Mentions" (the lowest category of my record list, The Supreme Recordings) sound better than the Romao LP, which I had placed in "The Divinity" (the highest category)? My personal thoughts at the time were; "What the hell is going on here? How could I have been so wrong in assessing both LPs?" Then we played both of the LPs again, back to back, using the Coincident amplifiers.

Both of the records sounded better, but this time the Saudades LP "wiped the floor" with the Klemmer. The respective sonics were now the same as when I originally played the two LPs on my own system (where almost all of the posted LP evaluations were made); the Klemmer was still excellent, but the Saudades was simply incredible; a great record. Just as I remembered. What could have happened that would mask the previously obvious qualitative differences between them? (And to such an extent that their qualitative rankings were reversed?)

My Interpretation of this Incident

I've long felt, and have now finally confirmed to my own satisfaction, that to hear, and appreciate, the finest recordings requires an audio system that does "the least harm" to the sonics. To achieve this goal requires an audio system with a simple, well executed and matched signal path. Anything less will pervert the audio signal to such a degree that the subtle musical qualities, which distinguish "excellent" from "great" recordings, will essentially disappear. This will then leave only those relatively gross musical qualities which, depending on the peculiarities of the system, could be fortuitously enchanced or, just as likely, even further compromised. Thus the inevitable result; fruitless and endless disputes about which recording is superior, based entirely on how well the recording matches the unique strengths and weaknesses of that particular audiophile's system.

In this instance, the Stromberg-Carlson's pentode output tube, push-pull circuit, as good as it was, was not able to pass all the exceptional amount of subtle musical signals on the Saudades LP. In effect, only the lowest, common denominator parts of the signal remained to compare to the Klemmer LP. The Coincident 300B parallel SET amps, however, were able to pass on that previously missing musical information, which then reversed the LPs' respective rankings.

Prior to this experience, I've never before heard such a clear demonstration of the superiority of an (single-ended) amplifier using D(irect) H(eated) T(riode) output tubes in such a definitive manner. This was much more than a simple "improvement", since both records sounded "better". No, the qualitative improvement in performance was so fundamental, that we couldn't even make accurate evaluations of the LPs' ultimate musical recording quality without incorporating them within the system.

This defining experience that WE had (my fellow listeners were also equally amazed by this LP comparison) was something I wish I could have shared with the multitude of fellow audiophliles who are still looking for a perspective, direction and strategy that will not fail them in the long run. Once you find the correct strategy, and I strongly believe that I/we have, the components themselves are much easier to evaluate and eventually become "secondary", which is their proper place to begin with.


The CAT is the most versatile, "powerful" and expensive amplifier we have ever made a Reference. It is also one of the finest in overall performance, though that will obviously depend on speaker matching and personal listening priorities and tastes.

Only one of our (tight knit) group as heard this amplifier in depth. However, he has an "all-out" analog system and extensive experience with every other amplifier on this list, plus hundreds of others in his 30 year audio "career". Still, I will add a personal "caveat" at the end.

The Facts

These are mono amplifiers that weigh 190 lbs. each! The "standard" model, which was both auditioned and purchased by my associate, costs $ 20,000 a pair. The "Limited" version costs $ 50,000 a pair. The output transformer weighs 55 lbs. by itself. The power transformers are even larger. This is a serious amplifier. The designer and manufacturer is Ken Stevens.

The JL-1 doesn't use (direct-heated) triode output tubes, like every other amplifier that has ever been in this class. It is also the first "push-pull" amplifier ever listed in this class. Instead, it uses (8 per channel) pentode tubes that are wired in triode. It is, like the more recent Jadis JA-80/200, able to work with 6550s, EL-34s or 6L6s. This particular model, used by my associate, was operated with 6550s.

(Important Note- A reader, who is also a distributor, informed me that this amplifier sounds best with the KR Enterprises KT-88s.)

The input tube (and phase splitter) are a 12AX7 and a 12AU7, plus there are two 6DJ8s used as driver tubes (which is unusual). The input tubes, as this is written, are still stock EIs from Yugoslavia, which will allow further sonic improvements to be made when the finest NOS tubes are used as substitutes.

A Short Sonic Description

According to my associate; "the JL-1s are the most emotionally exciting amplifiers I have ever heard". He feels they provide an overall "visceral" experience that is unique.

While they are rated at "only" 100 watts per channel, he claims they have more "impact, solidity, weight and control" than any other amplifier he has heard, and that includes many of the 500 watt (Jadis, Krell, Classe, Pass etc.) "monster" amplifiers, and the Altec/Tutay 1570 and Wytech Topaz tube amplifiers already on this list.

What about "refinement"; especially considering the CAT's triple disadvantages of a push-pull circuit, and 8 (pentode) output tubes per channel? He claims that the amplifier is still very pure, but not quite the equal of either the (also Class A) Wytech Topaz or the Golden Tube 300B in their greatest areas of strength; liquidity, purity etc. This observation is not surprising of course.

He felt that on digital sources, the differences were virtually inaudible, though on the finest analog sources, the above mentioned SET designs still had a noticeable advantage, but only on the best recordings, and even then, only where the music is simple and uncomplicated. On the other hand...

On high-power, complex orchestral works; he feels the JL-1s are so far superior in their (dynamic) strengths, that any "downsides" are "relatively trivial", and aren't worth talking about. This is the reason why he much prefers these amplifiers, overall, to any rival he has yet heard.

What about "value"?

Are they really worth $ 20,000 (in parts, labor etc.)? My associate has taken the amplifiers (not literally) apart. He feels they are very well built, but still somewhat overpriced. Of course, we don't know what the unique and gigantic output transformers actually cost to build, but he felt they should sell, in an ideal world, in the $ 15,000 to $ 16,000 range. They still offer equal, or better, value than most of the amplifiers in the $ 20,000 range. (Of course, considering their sonic achievement, they are the best value we know of in that price range, or above.)

Personal Caveat- I only "heard" these amplifiers once but, if I remember correctly, it was in show conditions, which is basically meaningless. My associate's "taste" is slightly different than mine. I favor purity and low-level information somewhat more than he does, but those qualities are still high priorities for him also. I believe his "taste" is more "mainstream" than mine is, so most readers of this website will probably agree with his assessment and feelings concerning these amplifiers.

What I know for certain is - knowing him as long and as well as I do - if a picky person like him is so impressed and enthusiastic about these amplifiers as he is, they must be damn special, and that's why they are here.

Further- Since the above observations were posted, the Antique Sound Lab Hurricane became available. According to my associate, it is "competitive", though still not quite equal to the CAT. It is now, in Triode operation, in Class B (Upper). It is only $ 4,400 a pair.

CAT JL-2- This is their current model. It is a stereo amplifier, in triode operation. None of us has heard it, but I have received appraisals of its performance from some readers, and everyone of them has been very impressed with it. One reader recently wrote that he actually preferred it to the JL-l in a direct comparison. Here is the relevant part of his letter:

(The JL-2)..."drives my Soundlabs M-2s like no other amp ever has. If your colleague loved the JL-1 monos he would find the lower priced stereo version "purer" with a lower noise floor but still outstanding bass (but not quite as good as the JL-1s). I had the chance to compare them directly as I wanted the JL-1s to sound better. As I am a monoblock type of person. ...They only looked more impressive, sounded fantastic but not as fantastic as the JL-2. The JL-2 reminded me more of the single ended triode sound."

More Recently- I just received a letter from Ken Stevens, designer and owner of CAT, which describes the differences between the "stock" JL-1 and the (more expensive) "limited edition" version of the amplifier.

"a) we bias the output transformer like an SE amp Biasing greatly improves low level linearity and IMO is the reason for the greater immediacy and vibrancy of SE amps.(when the owner sets the bias to read "0.0" it is then optimal inside the transformer).
b) We use a low loss core material - 12 times lower hysteresis than silicon steel and also better linearity. The net result with BOTH improvement above is 90 TIMES (no typo) greater linearity between small and large signals in the output transformer. Our current amps, the JL2 and the JL3, also use this technology..." (4/04)

Further Thoughts on the CAT Amplifiers- I have nothing new, but fortunately, a reader with extensive experience, particularly with all-out phono reproduction (he's one of the ELP contributors), has forwarded his observations concerning CAT's latest amplifier design, the JL-3. Here they are, with all personal references edited out;

"I have switched amps to the JL-3's... Naturally there was a 'trial' period in which I could return the amps if they didn't better the Wavac's. Happily (for my back, they weigh a ton!) they did beat the Wavac's. The immediate impression 30 seconds into listening is that they are both more transparent and smoother (in the hi freq) than the 833's. The second impression, the one that is something of a shock, is how well they do bass. The bass is full, powerful, controlled and well articulated. The bass of the Wavac's is anemic by comparison. While the Wavac's are still marvelous in the midrange, the JL-3's take those qualities and extend them to both extremes. The Wavac's sound more like a good tube amp while the JL-3's sound more like live music. In that respect the JL-3's remind me of the ELP is the way that it brings life to the music and increases the listeners indolent with he music. Too bad the ELP is in Japan being repaired as I can't wait to see if the ELP still sounds as good with the JL-3's. For sure the JL-3's will reveal any shortcomings in the ELP. For 3 years I've assumed I would never own another amp beyond the Wavac's. After all, how can you improve on 100 watts, Class A, SE triode? (I) guess CAT has figured a way."

Personal Note- Every person I know of, including one of my associates, who has lived with these various CAT amps has been "knocked out" by them, and that even includes veteran audiophiles who have already successfully used the finest single-ended triode amps in their system. The CAT amps obviously have some special qualities, which other (pentode output tube based) designs are missing.



The Atma-sphere is an Output TransformerLess (OTL) amplifier, and the best sounding of its type that any of us has heard, so far.

Its power rating is a nominal 60 watts per mono amplifier, but is highly dependent on the impedance of the speaker. It cannot* be used with speakers with a 6 ohms (or less) impedance, and it is at its best only with an impedance of 8 to 12 ohms (and above), regardless of what the 'reviewers', and even the manufacturer's literature, state.

At its best, meaning with a high impedance speaker, it has many of the qualities of the Class A amplifiers; neutrality, transparency, detail, excellent dynamic qualities and superior bass because of its direct coupling advantage.

The feedback used in this design is deliberately low and, if it is connected to high-impedance speakers, can be entirely removed, which further improves its performance. In fact, if this amplifier is totally stable with no feedback, that is the definitive sign that it is an optimum match with that particular loudspeaker.

It fails to make Class A because it lacks both the last degree of low-level musical information and the sense of immediacy that allows the listener to believe there is a direct connection with the performer(s).

Despite its appearance, with 8 output tubes per channel, the M-60 is actually a very simple design. The 4 input tubes are the amplifier's only gain stage, and they also double as phase-splitters. The output tubes operate as simple impedance matching devices, like a cathode-follower, and they have no gain.

This amplifier has a near cult status and there are countless ways to improve it. There was a kit available at considerable savings, but it was very difficult work and not for the beginner. It was discontinued at the beginning of 2001. There are a number of custom upgrades available from the manufacturer.

This company also makes larger and more expensive models, but their only advantage is greater power, otherwise they are not quite as clean, liquid, transparent and immediate as the M-60.

*Further- A reader has informed me of an accessory that may allow the owner of the M-60 to use it with a greater variety of speakers. Here is the information he sent me:

(The M-60) "mates well with speakers of low or uneven impedence when the "Zero autoformer" made and sold by Paul Speltz (see his web site) is connected between the amps and speakers. This may be done without speaker cables if the amps are located within 36" of the speakers. This raises the impedence by variable amounts so that the amp see 16 ohms or more at all frequencies. It is recommended by Atma-Sphere." (6/03)


The JA-80 is a classic design and the very first component that Jadis ever made. It is in this class only if it is highly modified and purchased used at a good discount (at least 60% off retail). The modifications include converting the unit to triode operation, in which case the power will be reduced to around 30 watts per channel.

The choice of tubes is also critical to reach Class B performance. I advise using the EL-34 with the only alternative being the Svetlana 6550C. With all of the modifications and updates you will have an amplifier similar in quality to the Atma-Sphere with noticeably superior micro-dynamics and a richer sound, but the JA-80 is inferior in the frequency extremes. However, it can be used with a wider variety of speakers. Unfortunately, the JA-80 requires a few hours of playing music before it sounds its best, which is longer time period than any other amplifier I know of or have ever used.

Jadis, of course, makes other amplifiers. Iíve heard most of them. The larger ones, each with two or more chassis per channel, have the same very desirable qualities that the JA-80 posesses, but they are all too slow and veiled to be a Reference, even with extensive modifications. Their prices are astronomical as well.

The smaller one, the JA-30, is actually superior to the JP-80 in precision and high-end extension, when both are equally modified, but it lacks the JA-80's power, bass extension and dynamics. It has around 15 watts in triode operation, which puts it in direct competition with the deadly Manley Retro and Neo 300B. The JA-30 is better built (hardwired), more reliable and less expensive to re-tube than either of the Manley amplifiers, but it also has a noticeable disadvantage in sonics.




This class should have around double the amount of amplifiers that are presently listed (7), since the standards of entrance obviously aren't as difficult to achieve as the top two classes. This will take some time, because I don't want to place an amplifier here and then have to remove it shortly thereafter. That would be unfair and unproductive to the readers.



The VAC is an excellent amplifier that can be switched from pentode to triode. This Reference designation assumes it is in triode operation. The VAC is similar in basic sound to the Atma-sphere and JA-80. It gives up a little in midrange purity to the (lower) Class B models (where it was originally listed), but it is still outstanding from top to bottom and it can drive a wide range of speakers.

While it is possible to improve the stock VAC, it doesnít require any "extensive" modifications. VAC has made a wide variety of excellent amplifiers for years; but these are the best value we have heard from them when considering the combination of cost (used only), power, build quality and overall sonic performance.


The best amplifiers ever made by VTL (with the possible exception of their rare and expensive direct-heated-triode models). These are real sleepers with excellent speed and detail like good solid-state amps, but they also have the natural body and richness of tube amps. Even the bass is excellent, with the right speakers. They donít have a lot of power, only 25 watts per channel, so speaker choice is critical.

They can be improved quite a bit with modifications.
1. Changing the coupling capacitors.
2. Adding power supply shunts.
3. The feedback capacitor can probably be completely removed
4. The feedback resistor can probably also be changed (increasing the value reduces the amount of feedback.)
5. If you can get away with less power, you can even remove one push and one pull output tube per channel that are closest to the chassis. (the bias must then be changed).
Don't attempt these modifications unless you know what you are doing!

These amplifiers are far superior to others we have heard using the EL-84 output tube. Donít be fooled by their small appearance, they sound "big". They are an incredible "tweeter amp" too. Manley Labs also has its own version of this amplifier that is supposedly even better (both in sonics and build quality), though it costs a little more. We haven't heard that model yet.


The Lumley amplifiers are manufactured and designed in England. The M-100 is now discontinued, but, as far as I know, the M-150 is still current. Both are excellent, combining power with finesse. They must be modified to reach this Class. We assume they will further improve if placed in triode operation, but we never got around to the procedure.

The M-150 has a noticeable edge in sound quality, output power and looks, but they will cost more. Both will work very well with a wide variety of speakers, but beware of dynamic speakers with either a very low impedance or poorly damped woofers. The M-150 is a particularly good match with the Martin-Logan CLS. "A poor man's Jadis."


The Rogue amplifiers are available new for around $ 2,500 per pair. They can be switched from pentode (120 watts) to triode (70 watts). They sound quite a bit better in triode operation and with no downsides.

They are excellent performers excelling in every way, with exceptional control of woofers and superb dynamic capabilities. The passive parts are mediocre* (that's being kind), but they can be easily upgraded after the warranty expires. They are also well built for the money. This is one company that looks like it can take on the Asian tidalwave.

Their stereo amplifier (Model 88) is also an excellent value for the money, but itís worth the extra cost to move up to their monoís.

CAVEAT: There appears to be unit to unit variation with these amplifiers, so check them out before you commit.

* I have been recently informed by a reader that there is now a factory upgrade (The "Magnum" Series) using higher quality passive parts and that this upgrade is also "reasonably priced".


Believe it or not, the Sakura is a solid-state amplifier! It is an extremely simple design with 25 watts per channel. There are a few areas of concern.

Great care must be taken with the choice of speakers. It is best left on 24 hours a day, since it only uses 10 watts or so of power. A breakthrough, finally, in transistor electronics, and it was achieved by simplicity and proper execution, not by brute force and overkill. This amplifier is even more natural than some tube amps.

Donít be fooled by its very tiny size, this amplifier is for real. It is overpriced though at $ 3,300 including its separate power supply. I hope someone in North America will make an equivalent amplifier, which would sell for half the price, or even less.

This company offers excellent service.

Further #1- There is also now a new 50 watt version of the Sakura, and it only costs $ 700 more. According to my associate, the 50 watt amp isn't as good, but it still may be worth the extra $ 700 if you require the extra power.

Further #2- A reader has informed me that he replaced the stock power supply of the Sakura with a pure DC battery version of it. He claims to have heard a significant improvement in sound quality. It is even possible that this battery power supply may become a commercially available product. Stay tuned.


These models were all overlooked when I first put this list together. These are the finest amplifiers, overall, for the money, that I have ever heard. Every single model they made is a Reference, except those from their First Generation.

The models I consider References are the: SA-12, SA-20, SA-100, SA-220 and (all) the Natural Progressions. All these models have similar strengths and weaknesses. They all have exceptional detail and musical information for their power ratings. They are the perfect choice for those audiophiles who need both power and "musicality", and don't want to pay "big bucks" for it. (They embarrass most of the more expensive amplifiers from Krell, Levinson etc.) Their weaknesses are not serious for their price point; a small, though noticeable amount of dryness and thinning of timbres (or loss of low-level information).

Counterpoint is now out of business. This is a tragedy considering that many other manufacturers, who made inferior and/or overpriced components, are still around. Fortunately, the original founder and designer of Counterpoint, Michael Elliot, is still in business to repair and update most of the models, but he is not "cheap". (See the "Links" section to reach him.)

For those who can't afford the expensive updates by Michael Elliot, all the above models can be improved by simply replacing the (now obsolete) coupling capacitors along with some judicious "tube rolling".

Caveat: The SA-20 model, unfortunately, used very rare MOSFETS that can't be replaced, so make absolutely certain that it's working properly. It can still be "updated", by Elliot, even if it breaks (or is broken) down, but at a much higher price.


A reader sent me a letter, below, which inspired me to focus on these amplifiers once again. I realize now that I should have made these amplifiers "References" when I first created this list back in 1999. When I finally remembered them a few years later, I was too hard on them, because they did have problems with a lot of speakers, at least those designed and built years ago. They sound their best with speakers that are both efficient and easy loads. These speakers are much easier to find now. The Quicksilvers are also hard-wired and easy to modify, which I highly recommend, since I modified a number of them successfully myself.

I was a dealer for this amplifier back in the 1980s. It was an exceptional performer, especially for the money, though it was overrated somewhat by The Absolute Sound; coming in "third place" in their superb amplifier survey in Issue 36 in 1985. (Read that survey if you can, and then compare it to the garbage they publish today for absolute confirmation of the full extent of their "fall".)

The Quicksilver was very natural sounding, with good separation of instruments, and an excellent sense of immediacy and transparency. The high frequencies were rolled off and transients were softened somewhat, though these areas could be improved with capacitor changes. (Which I did myself on several occasions.) The bass was noticeably mushy, like most tube amps, and lacked real impact on most speakers. One practical downside was that their output tubes were run harder than normal, so they had to be replaced more often than most other tube amps. (They changed the output tubes, and their was (is?) a dispute about which tube sounded better. I never came to a definitive judgment about that.)

I remember them beating out most other amps anywhere near their price point (on suitable speakers), but they were no match for the Jadis JA-30, even when they were modified, operated in triode and the Jadis was stock. Of course, the price difference was also huge. I would seriously consider these amplifiers if you can find them used, in good condition and at a reasonable price, 40% (or more) off their former retail price. They may be even more desirable in a bi-amp situation; handling only the mids and highs.


These are truly unique amplifiers, with unlimited current, and true (no B.S.) Class A operation. As an example, they are rated at only 25 watts per channel in 8 ohms, but each mono amplifier delivers 400 watts in .5 ohms! They are a marriage of both quality and quantity, at least in low impedance and ultra-challenging loads. They are best known as the amplifier of choice for the original Apogee Full-Range speakers, which had a .3 ohm load, making it the ideal speaker for the ML-2.

Also, don't overlook the Mark Levinson ML-3, a contemporary of the ML-2, which was totally different in design. It was stereo, with incredible power and weight at higher (and more typical) load impedances (4 to 8 ohms). I heard it a few times in my old retail store, and I can confidently state it was the most impressive "high power" amplifier I heard in its day, and I heard them all back then.

For further information, and for some of our anecdotal experiences with the ML-2, see The Original Apogee Speaker, Mark Levinson and Krell Amplifiers essay below.


Sunfire 300X2 (Load Invariant) Power Amplifier

This particular Sunfire model (and I assume the 600X2 "sister" version, which has twice the power) is an exceptional amplifier. In fact, I believe it is one of the most important and imaginative designs in the entire history of amplifiers. While it definitely is NOT even close to being one of the best sounding amplifiers I've ever heard, it does have good (and better than expected) musical performance, plus two other important virtues, making it an unique component from my perspective. The details are important, and "the big picture" regarding amplifiers is also something that I feel must be discussed in this instance, because the Sunfire may be a highly useful and desirable component for many audiophiles.

First the set-up I heard in my own system: I used two Sunfire stereo amplifiers (4 channels in total), with one stereo amplifier dedicated for each L/R channel. In effect, I had complete separation, as with mono amplifiers, using one channel of each Sunfire only for the monitor and the second channel only for the subwoofer. I used the "Lab Direct" RCA inputs and the "Voltage Source" speaker outputs, which provide the least* amount of "filtering", and thus are the most accurate options. My Reference System, otherwise, remained exactly the same. Now on to the sonics.

*There is still one more filter requiring an internal modification to remove. See below for further details.


The Sunfire doesn't have the typical problem of an obvious "transistor sound" (a "commission"), but it does subtract musical information (an "omission"), and lots of it (compared to "the best"). It can play extremely loud, and cleanly at that, but it still compromises true dynamic intensity ("explosiveness"). The bass goes deep, but it's not as impactful, detailed and controlled as the finest I've heard (and that includes even some tube models).

The Sunfire does have a somewhat more natural and full-bodied sound than average transistor amplifiers, which is the critical factor for those audiophiles who consider non-tube amplifiers as a viable option, but are still highly discriminating when evaluating them. As for myself, I feel too much of the music is lost to live with them, but that is also probably true (for me) with any transistor amplifier, at any price, at this time. So why do I feel the Sunfire amplifiers are so special?

Simple, when considering its unique ratio of Quality, Power and Cost (QPC), I believe the Sunfire could be a great value, possibly unprecedented, particularly if it fits into an audiophile's priorities. To better explain this position, I created an easy to understand chart, with explanations below it.


There are three fundamental amplifier categories (QPC), and five Levels in this chart. I realize that everything in the chart is subjective and even arbitrary on my part (including the number of Levels), but it's required to help me illustrate a larger concept, so please bear with me. (Readers can always create their own "Levels" if that makes the chart easier to understand and more practical.)

$ 1,000 (AND BELOW)
$ 3,000 RANGE
$ 5,000 RANGE
$ 10,000 RANGE
$ 20,000+

*An "indulgence" (?), maybe, but I've never heard another amplifier design equal an outstanding SET ("at its best") at reproducing music.
**This particular Apogee is the single most difficult speaker I know of to drive properly.
***I'm equating transistors and pentode tubes in this particular instance, even though each has many adherants that would never consider the alternative.


First, it must be understood that all three categories are almost always in direct conflict with each other, or "mutually exclusive" (just like a battle tank's armour and speed are mutually exclusive). Examples- Reduce the cost and both the power and quality are adversely affected. To increase the quality means both increasing the price and reducing the power. Increasing the power will reduce the quality and and increase the price. This is why no amplifier has been, or can ever be, a "1" in everything (such a theoretical amplifier would be three X "1"; a perfect Total "3"). In fact, it's extremely difficult to even come close to a 3. However, there are some exceptions, and it's these amplifiers that are (or should be) the models that serious audiophiles focus on.

Finally, I used the number "1" as the "Most Desirable", instead of number "5". This is because it is easier to demonstrate the differences between the Total QPC of the amplifiers using smaller numbers.

Some QPC Examples

So, how do some well known amplifiers fare on this chart? The Coincident Frankenstein, which is my "Personal Reference", starts off really well, getting a 1 for Sound, but it gets a 5 (or at best a 4) for Power and a 3 in Cost (Total 8 or 9). What about the classic Dynaco Stereo 70* (with some economical updates)? It gets a 3 for sound quality, a 4 for power and a 1 for cost (Total 8). Then there's the well known Counterpoint SA-12/100, long-time favorites of mine, and for good reasons; a 3 for both sound and power, and a 1 in cost (Total 7).

*The date of the chart may change the numbers. In the 1960s, the Stereo 70 would have received a 2 for sound, 3 for power and still a 1 for cost, giving it a Total 6.

Another favorite of this website is the ASL Hurricane, which can be purchased used at a very decent price; It gets 2 for both sound quality (in triode) and power and (now even) cost(!), so that's a Total 6. In short, a used ASL Hurricane could be an incredible value. Finally, what about the amplifier(s) now under discussion, the Sunfire? Well, here it gets very interesting, and maybe even unprecedented.

I would give the Sunfire a 3 when it comes to sound quality, placing it in the same general sonic level as the Counterpoint and Dynaco, though (far) behind the Coincident Frankenstein and also noticeably behind the Hurricane, but then lightning strikes twice. The Sunfire gets a (very rare) 1 for power and another 1 for cost, making it a Total 5! That is an incredibly low number, and I've been racking my brain to find another amplifier to match it. It certainly won't be easy.

Here's an example: Let's imagine that a brillant audio designer, who is also prepared to work and live on the smallest profit margin possible, creates an inexpensive version of the Frankenstein amplifier, with sonics almost as good and costing only $ 1,000 a pair. This imaginary amplifier would receive a 1 in both quality and cost! However, there's still the power factor to take into account, where it gets a 5, bringing it to a Total 7, demonstrating again how difficult it is to get to a honest low number.


I was impressed enough with the Sunfire to create a new Reference Class just for it; Class C (Lower). I did this to distinguish it from the "Entry Level" amplifiers. However, no amplifier is suitable for all the members of any sub-group of serious listeners, and that includes the Sunfire. Audiophiles will have to judge for themselves whether its unique qualities are a match for their needs. Further, the Sunfire has some practical "features" that I do not like and which, even worse, compromise its sonic performance. This leads us to the next inevitable (bonus) topic...

Upgrading the Sunfire(s)

For a period of time, I was seriously considering keeping the Sunfire amplifiers as my system "backups". During this period, I came up with some simple and economical "modifications" that would make them more practical, and safe, to use on a daily basis, while also possibly improving their performance. I will now share these modifications, with the usual caveat that all modifiers are on their own, especially since, in this case at least, I have not performed any of these modifications myself. To make things easier, I have provided a picture of the inside of one of the Sunfire amplifiers I used in my system.

Sunfire 002

The upgrades, or modifications, to the Sunfire are in two general categories:

1. AC Power Upgrade

Explanation- The Sunfire has an attached power cord instead of an IEC jack. Even worse, it has NO on/off power switch. Thus the Sunfire's performance is being compromised, while also wasting unnecessary power at "Idle" (45 watts), and it's even highly vulnerable to power surges (let alone unexpected lightning strikes). So I would make these two changes:

A. Remove and replace the built-in AC power cable with an IEC jack, which will allow the Sunfire to use any type (and length) of power cord.

B. Install a heavy-duty/high current power switch (on the back).

2. Capacitor Removal and Upgrades

Explanation- The Sunfire has a capacitor on the speaker (output) binding posts, which rolls off the highest frequencies. It also has (unremovable) capacitors which can be upgraded. So I would make these changes as well:

A. Disconnect the output capacitors, one per channel, attached to the speaker binding posts (just cut the wire, so you're certain they can be easily resoldered if necessary). These yellow capacitors can be seen at the lower and upper right corner of the picture.

B. Upgrade the 6.8 uf film capacitor to a higher quality type of the exact same value, something like a Solen Teflon. The voltage should be the same as, or higher than, the original cap. It may be also possible to increase the value from 6.8 uf, but I am not certain of this. I believe these capacitors are on the circuit board seen on the left side of the picture. There are two of them, one per channel. I would also add a .01 uf capacitor, of the same type, in parallel with the 6.8 uf replacement capacitor.

C. Add two film capacitors to the main B+ power supply reservoir (the two large blue capacitors seen at the upper left corner of the picture). Use the largest value possible, probably made by Solen. The voltage should be the same as, or higher than, the capacitors already installed (which will remain in the amplifier).

Important- These capacitor changes should always be done, and auditioned, one at a time. While I do not expect any problems, a mistake could be made and it is important to know which step caused the problem.

Final Thoughts

I believe that the (original Load Invariant) Sunfire amplifiers, because of their unprecedented combination of above average performance and almost unlimited power capability, at reasonable prices, constituted a "breakthrough" of sorts. Unfortunately, this was generally unrecognized at the time by almost everyone in the audiophile community (including me). That's in the distant past now, and I realize that this belated review is a poor substitute for the injustice of their prior neglect (in which they are not alone), but it's all I can do at this time.

Still, I am an optimist at heart, at least with audio, so I will finish this review with a suggestion that is easily achieveable: It's now way past the time for "all-out" versions of the Sunfire amplifier to be designed and marketed; by Sunfire, or someone under license or even by Bob Carver himself. What I mean by "all-out" is this: Mono amplifiers; a completely unfiltered signal path; with the highest quality power supply. Two versions; one of them ultra high power (suitable to drive anything) and a second model that is "minimalist" in design (the highest quality, and fewest possible, components in the signal path), but still possessing enough power (and headroom) for most speakers.

These theoretical amplifiers would not get a "4" or even another "5" (because of their extra cost alone) on the "Value Chart" above, but I believe they would still offer a unique choice, and outstanding value, for those many audiophiles who are looking for high performance, along with serious drive capability, and without paying a fortune for it. They might even be "buy it and forget it" components, that are used and enjoyed for many years and even decades, which, in the end, is just another way to define audiophile "Classics".


Other Interesting Power Amplifiers

Wavelength Cardinal

This is one of the finest stock, single-ended, 300B amplifier that any of us has heard. In fact, this amplifier was originally in our Class A when this list was originally posted in 1999. It is superb right out of the carton. For those who want the basic performance (for better or worse) of the discontinued and modified Golden Tube 300B (in Class B), and without the hassle and the work, this is the closest and easiest approach we know of at this time. However, the obvious and painful downside is the extra cost. The Cardinal does have one sonic and practical advantage over the Golden Tube, in tests in Stereophile, it had the lowest bass per its power rating.

None of us knows if a modified Cardinal would equal, or even outperform, the (highly) modified Golden Tube. The problem arises from the fact that the (stock) Cardinal is very well built in the first place, and uses excellent passive parts, so that a modification will most likely only achieve modest results. There is also a more recent Napoleon model, which is more expensive and is supposed to be even better, but it is rare and none of us has heard it.


This is a Canadian company whose components I am very familiar with. They have been around for decades now, and while I was never a Bryston dealer when I was a Toronto retailer, I received dozens of them as trade-ins over the years. I also heard them countless times at customers homes. I even owned a few of them myself, the original 2B, 3B and 4B.

Despite the many amplifiers they have come out with over the years, it is easy to generalize with this company, because their (very popular) components are similar in basic design and evolution. In the early 1980s, their models were noticeably "above average" (for solid-state) and very good value. Today, they are still "above average" in performance (for solid-state), but only slightly.

Their later models are cleaner, faster and more transparent than those of decades ago, but their competition has improved even more. They are still "good value", but they should be purchased used, especially considering how many are out there. The risk is small, because reselling them is usually easy.

Bryston's greatest strengths are its virtual "bullet-proof" designs and good build quality. Even more impressive is their factory service, which is probably "the best in the business". A good number of their (extremely satisfied) customers informed me how Bryston repaired their amplifiers (for free), even some "out of warranty", while they had a coffee, and the repaired amplifiers sounded even better than when they were new. Such dedication is rare in any business.

I advise seriously considering these models mainly for people to who need a place "to park", before they make their serious committment. They are in the "Entry-Level" section for their practical nature, but their sonic performance, on its own, can not be compared to the superior Class C amplifiers above.

Audio Research (ARC)

I realize some readers may feel it is unfair to describe around three dozen "different" amplifiers from one (very famous) audio manufacturer but, as is the case with Bryston above, ARC has had a pretty basic design philosophy and "sound" for more than two decades now. This makes things easy for both the prospective purchaser and any person attempting to describe the "house sound" and their reaction to it.

In my case, I've had a number of their more recent models in my (now former) store as trade-ins. I also heard a number of others in private homes, audio shows, etc. The sound of these models was very consistent.

The ARC amplifiers, not counting those from the 1970s (meaning the amplifiers up to and including the D-79), are all fast, clean, neutral, detailed, dynamic and with increasingly tight, detailed and impactful bass. They are also harmonically lean and dry. In effect, they sound similar (though still superior) to the finest solid-state amplifiers I've heard.

Most people will probably not be bothered by this type of sonic "character", but anyone who has read this website in any depth knows that I am bothered, "big-time".

From a long-term perspective, ARC was challenged, around 30 years ago, by the new (at the time) Jadis models, which had the multiple advantages of being hardwired, with Class A circuits and custom made output transformers. Ten years later came the direct heated triode revolution. ARC never really took up either challenge, but they survived and even thrived anyway. This success has always been a surprise to my associates and I.

I could never live with any of these amplifiers, though I do recognize their strengths and continuing popularity. Many audiophiles love their combination of virtues, but from my personal perspective, the best I can say about them is that they may make excellent bass amplifiers for those in a bi-amp situation, who also require the unique qualities of tubes.

Further- I believe in "audio synergy", and I've noticed more than once that ARC amplifiers, especially their latest models, work particularly well with Vandersteen speakers. In fact, they're one of the best synergisitic matches I've ever experienced, with both the speakers and amplifiers sounding the best I've ever heard them.

Manley 250 Neo-Classic

This is a high-power tube amplifier in the $ 9,000 price range. It is also well made, with 10 output tubes per channel, and with an interesting appearance. I haven't heard this model, but an associate has, and with equipment he is intimately familiar with. He compared the amplifier for me to the Antique Sound Labs Hurricane, another amplifier he is familiar with.

Unfortunately for the 250, the Hurricanes are less than half the price and, according to my associate, noticeably superior to the 250 in virtually every area that matters in music reproduction; transparency, dynamics, control, image size, bass etc. On the other hand, this same associate claims that the Manley is still more satisfying overall than any of the recent ARC models he has heard (which is everything but the "Reference" models).

It's going to be extremely tough for typical North American audio manufacturers, with typical "conventional" designs, to compete with high-quality Asian components, which sell for a fraction of the price. Manley, with their track record of innovative designs and their commercial customers, is much less vulnerable than most of the others.

So far the magazines have done a pretty good job of protecting their "local buddies" by simply ignoring the Asians (except for cartridges and accessories) and avoiding any free publicity (serious 'reviews'), but that will not stop them in the long-run.

The word on these Asian components is already out on the Internet. The Asians are also learning English. Now it's just a matter of time.

Tenor Audio Models 15 Wp/75 Wp

These amplifiers, from Quebec, use tubes, the Russian 6C33C-B, but have no output transformers. They are OTL designs. Both of them are dedicated power amps, though there are two other models that are the same but also include a selector switch and a volume control, so they can bypass the preamplifier.

More than one experienced listener has claimed they are the finest amplifiers they ever heard. We were not able to get a loaner, but one of my associates finally had a chance to hear both of the two pure power amplifiers in his friend's system, which he is very familiar with, for many hours. This is his report:

He feels that the 15 Wp is "superb". It has exceptional inner detail and transparency, plus it is very clean, though it doesn't equal the finest SETs in those areas. For 15 watts or so, it has more sense of power than one would expect, but it was not even close to being competitive in that area to the Hurricane, which is, in turn, inferior to the Tenor in its strengths. The real problem with this amplifier is its price; $ 18,900 a pair, around double the price of the (equal or superior in almost every way) Wytech Topaz. It is very well built, but not hard-wired like many of its less expensive competitiors.

The 75 Wp doesn't cost much more. It is $ 20,900 for a pair. It is very similar in design except that there are twice the amount of output tubes, and the power rating goes up to 75 watts. Unfortunately, it is a step back from the 15 Wp. According to my associate, not only does the 75 Wp not sound much more powerful than the 15 Wp, it also doesn't have quite the exceptional purity, inner detail and transparency of the 15 Wp. He much preferred a number of amplifiers to it: The Antique Sound Labs "Hurricane" and AQ 1009, the Wytech Topaz and a number of 300B amplifiers. He told me, "Sure the 75 WP is a good amp, but there's 'no comparison' to the others". All these direct comparisons were made with high efficiency, high impedance speakers that my associate was very familiar with, allowing the Tenors to be heard at their best. The other components in the system were also familiar, and constant.

We suspect that the (relatively subtle) sonic problems of the 75 Wp, and even the superior 15 Wp, are caused by their use of feedback. However, as far as I am concerned, these amplifiers will always be fatally handicapped by their retail prices, which are totally unjustified considering they are OTL amps with a few, inexpensive tubes. They should be selling for less than half their current price. The competition from Antique Sound Labs, especially the AQ 1009, the Topaz 572 and (from what I hear) the new deHavilland 845, all selling for less than half to a quarter of the price, makes the Tenor amps, as good as they are, a dubious and high-risk investment, at least at their current retail price. (See the LAMM amps below for a "deja vu" experience.)

Important Note- I want to make it clear that I don't hold Tenor fully responsible for the pricing of their amplifiers. Many manufacturers, especially those new to audio, are forced to price their high peformance models to ridiculous levels to fit into the existing "industry standards" set by the audio magazines' editors and reviewers. It's either that or be ignored, period. Why? The magazines don't want potentially superior components to be significantly less expensive than the models they have previously raved about. It's too embarrassing for them and it would also immediately threaten the viability of those more expensive models, along with any of their equally high-priced replacements. I should add that most retail stores also don't like "overachievers" either, which is why the current state of "establishment audio" is where it is.


This veteran (1934!) company has come out with a number of amplifiers over the years. I have limited experience with their line, mainly a few models from the 1970s and 1980s that came in as trades. The models I heard, now more than decades ago, had more problems than their North American counterparts, and they cost more because of the extra expenses of importing them. I also found them visually very unappealing, though that is, in the end, irrelevant.

Their main sonic problems were basic and very noticeable: lack of power, poor bass, rolled off highs, lack of transparency and precision and compressed dynamics. Their midrange and refinement were competitive, but not superior, to their equivalent U.S. models.

Trilogy 958 Triode Reference

This was an amplifier from England, which never had distribution in the U.S. Now it is discontinued and unobtainable. It is push-pull and uses EL-34 output tubes. In the recommended triode operation, it has around 60 watts per channel. Listening was done by one of my associates, who was so impressed that he ended up purchasing a pair. He had heard most, but not all of the amplifiers that were References in the highest classes. I have not heard them yet.

It has strengths in many areas including; superb highs, speed, dynamic shadings, immediacy, low-level musical retrieval and accurate tonality with body. It doesnít get that last bit of directness that the best single-ended designs do, but itís close. It works with a wide range of speaker loads, like the JA-80. The cost in England was around $7,500 for a pair. I have been told that the "secret" of this amplifier is its very unique output transformer.

According to my associate, this amplifier has Class B performance, and it was located there until recently. It still competes with the other Class B models, but it is essentially impossible to find, especially in North America, and no more will ever be made, so it has become more of a dream than a practical choice. For those fortunate enough to stumble on a rare pair of them, take immediate advantage of your luck, and don't let them go without checking them out.


I heard the Lamm amplifiers three times that I can remember. Once in New York for an afternoon (with Vladimir Lamm, president, designer, and nice guy, present), another entire afternoon in the home of (now late) reviewer Lars Fredell, and once in a customer's home. One of my associates is much more familiar with them than I am, since he shared a room with Lamm for at least one or more audio shows, and heard them on a number of other occasions, including the afternoon with Fredell.

Neither one of us was excited by the hybrid model we heard (circa 1996), but the ML2 was clean, natural and detailed. It was about as good or better than anything around with its modest power rating, including the Trilogy 958 above. As usual, it only gave up something to the finest (DHT) SET amplifiers, but it still had the typical advantages in power and bass control.

Its "secret" advantage lies in its unusual output tube, the 6C33C (also used in the ML2 for voltage regulation, the original function of this tube). It has an exceptional amount of current, so it requires less transformer windings, which in turn means a purer, more extended and more transparent performance. On the downside, since the 6C33C was designed for voltage regulation, and not amplification, it has some inherent instability. Whether this is audible has not been established, but the certain problem with the ML2 was, and is, the retail price.

Nothing that I saw, and I looked at the amplifier very closely more than once, justified the huge retail price of the ML2, almost $ 30,000. Since then, I have been able to view pictures of the inside of the amplifier. My initial judgment was only further verified, and the amplifier is not even hardwired. With normal industry markups, a pair of these amplifiers should be selling for less than $ 10,000. (Of course, like Tenor above, these crazy prices are required by most audio 'reviewers' before they will take an amplifier, or any component for that matter, "seriously".)

The ML2 has since received "raves" from a variety of sources. Unfortunately, and despite what they think, most of these highly impressed reviewers have had limited experience with the finest amplifiers around. (These "finest amplifiers" are rarely from the "well-known" companies that can both advertise and "loan" out their components for extended periods.) Furthermore, not even one of these reviewers questioned the retail price of the ML2, which makes their overall perspective, "critical nerve" and their final assessment, all highly suspect. Even when they were right concerning just the sonics, there has been a change since then.

The competition for the ML2 has profoundly changed. First there are the Canary CA-339, deHavilland 845 & GM70 and Tenor OTL amplifiers. Even more pertinent, the Antique Sound Labs AQ1009 is only around 20% of the cost of the ML2, a more than $ 20,000 savings.

I advise listening to these alternative amplifiers, and especially the latest AQ1009, before purchasing the Lamm, with direct comparisons preferable. At least you will know exactly what you are getting, if anything, for the extra $ 20,000. There's little doubt that the Lamm ML2 is an exceptionable amplifier, since it has impressed virtually everybody who has heard it, including the most picky, but at its current price, there are plenty of viable alternatives, most for far less money.

Request- If anyone, or preferably a group, makes such a direct comparison (ML2 Vs. AQ1009, Canary CA-339 or deHavillands etc.), I would like to know the results, with all the details.

Musical Fidelity

This English manufacturer has received an incredible amount of attention and hype from Stereophile, with a prominent mention and/or a full 'review' of their equipment in nearly every single issue. MF also, quite predictably, has many of its components included within Stereophile's so-called Recommended Component List. It is very tempting to write that all this "superhype" is totally undeserved, but that is not the case.

I've had a number of lengthy experiences with their integrated amplifiers, and their CD players. In each instance, the result was favorable, offering "above average" performance for the money. This is especially true of their earlier models, which were co-designed by Tim De Paravicini. The sound was cleaner and more natural than typical solid state. The components were also well built and had a "solid feel" to them. While they are not quite good enough to meet the standards of "Class C" in this list, they are certainly good enough to be included in the Reference Entry-Level components.

Look for them used only, which should be easy considering their somewhat contrived and excessive popularity, mainly caused by Stereophile's embarrassing surplus of (mainly) accolades, and the fact that they are continually coming out with new models, and subsequently discontinuing their older models. (5/03)


Over the years I've been repeatedly asked to comment on the components from Sonic Frontiers. I must first disclose that the two people who started Sonic Frontiers were once my employees (Chris Johnson and John Sloan). That's actually how they met each other. They began by selling mainly parts and kits and finally fully manufactured components. I was never one of their dealers. The final two owners (one of them was Johnson) were marketing men, not engineers or designers.

I've only heard a few models from Sonic Frontiers, mostly from their early days, and I wasn't impressed with any of them. The one exception was their final CD player (the SFCD1) before they went bankrupt, which was excellent. It was designed and built by outsiders, as far as I know. Their power amplifiers, both early and late models, are to be avoided. This advice is based on the experiences of my associates, who feel they are below average in performance for their cost. I, and my associates, heard the earlier preamplifiers, and found them veiled and mechanical (dead). None of us has had any direct experience with their later preamps. There were also reliability problems with some of these components.

I have no experience with either the Anthem or Assemblage line. As for all the "rave reviews" they received in the past, especially from Stereophile, I would totally ignore them. It should be remembered that until they had financial problems, Sonic Frontiers spent more money on advertising than any other audio company I'm aware of in the "high-end".

There was one important and telling indicator of the true quality of most Sonic Frontier's components; The fact that they would almost always show up in the used marketplace within a few months of coming out; in quantity and at huge discounts. The owners couldn't wait to sell them off, and at any price. That harsh reality means infinitely more than all their 'reviews', hype, claims and flashy ads. (9/03)


Here's the latest information about these interesting amplifiers, and the history of the particular pair that ended up as the "Coincident Frankenstein". It is from Robin Wyatt, owner of Robyatt Audio Products. With some minor editing:

"I am very aware of those ("Frankenstein") amplifiers, as they actually changed hands many times. A gentleman in Chicago had them and tried to sell them back to me after the mods, probably the guy you mentioned. Then they went to an existing customer of mine in Baltimore. He had a Tektron integrated on Avantgard Duo's. Firstly, we found them overly noisy on the super efficient Duo's. I agree, in some areas, there were some improvements to the stock TK50M's. However I found that changing tubes, both brands, and types, made more of a sound change! The Tektrons are unique in the fact you can run three different tubes by switching filament voltage.

We did have serious problems at first with the US versions of the amps, because I specified a switch instead of internal hard wiring, as in the Italian versions. Those amps were early production. The original switches melted shut at 5.0V, allowing the use of only the 50 tube unless the switch was disabled, and hard wiring adopted! That is no longer a problem, as we use a $35 super switch from Japan!! Then we put a Sophia Electric "Princess" tube in the Tektrons, running at 3.5V, with no other modifications needed. This is the only amp I know that will run this tube apart from a now discontinued Sophia model. If you liked the "Frankenstein's", you would have been blown away with this combo!! I had to sell the tubes to the gentleman, he would not let them go. Note- These were the "Princess" tube Sophia sells, that is a cross between the 300B and 105D, and Not the new 300B "Princess". I believe the Brennemans were sold shortly after...

I will be demo'ing these amps at VTV Show, at the Embassy Suites, in Piscataway, New Jersey, May 6th and 7th.

Michael Lavorgna, of 6Moons, has one right now, and has heard how the "Princess" tube far out perform any new or NOS, 2A3, 45, 245, 345, 300B, 300BX, 50, 250, 350, 463, VT52, I put in the amps, be they EML solid plate 45's (his) or RCA Cunningham 1930's mesh plate 50's (mine)!!!

I will demo a stereo amp and pre, and will be using RL Acoustique Lamhorn 1.8's with AER MKII drivers, as well as the intergrated Tektron, with an Ipod type set-up, (must not forget the young crowd, our hobby is getting older!).

...Yes, the Sophia Princess is still available at Sophia Electric, and I believe existing 300B type amps can be modified!"

Personal Notes- I'm particularly intrigued by the Sophia Princess output tube. If Wyatt is correct, it could be a serious development, and the required modifications are probably not extensive, nor expensive. There's no question that the Tektron is an unique amplifier, especially suitable for those audiophiles who want to try a variety of low-power SET designs, while avoiding a huge initial investment in both time and money. They're also compact, attractive and have a proven history of successful modifications.

Symphonic Line Amplifiers

I'm familiar with these amplifiers, because I heard them on a regular basis during the early/mid 1990s, in an audio store located in the same building that I lived in. I even had a chance to hear them once in my own system. They were among the finest sounding transistor amplifiers I've heard, with a natural, non-fatiguing character, plus they were clean and had good detail. They were also well built and have a simple, elegant appearance. They weren't "crazy priced" either, so a used model, at a reasonable discount and in good condition, could be a very desirable purchase.

For those audiophiles who appreciate the performance of the better tube amplifiers, which I still obviously prefer, but can't use them for whatever reason, the Symphonic Line is a good alternative.


I just found out about this new stereo amplifier from the veteran manufacturer, Music Reference (Roger Modjeski). It uses the 6EM7 (or a 13EM7) dual-triode tube, which they use as both the driver and output tube. It's not very powerful of course (2.5 watts), but it should sound very pure, dynamic (for its power) and complete. Its "introductory price" is $ 800, going up later to $ 950. This is the same tube that's in both the Coincident Frankenstein and Dragon. This is why it is also here, along with this company's excellent track record.

Exact URL:

Esoteric Audio Research (EAR) 509 Amplifier

I've been also asked about this amplifier a few times by readers. This is what I wrote back:

I had a number of EAR 509 (and other models) in my store in the 1980ís. In fact, I think I was even an EAR dealer for a while, and modified at least one pair of them. The 509 had two big pluses (and maybe more); an amazing dynamic impact/intensity and their outstanding bass reproduction (especially for tubes). They made most other amplifiers of that time sound like anemic wimps. However, I also felt they were ďdirtyĒ sounding and somewhat unnaturally bright. I preferred the earlier Michaelson and Austin TVA-1, which had the same sonic advantages, but was more natural and cleaner sounding. In conclusion, I would seriously consider these only for the bass when bi-amping. I've never done this myself, but based on what I've heard in the past, the results could be well worth the investment. (4/08)

Naim Electronics

I am asked about the Naim line from time to time, so this is how I feel about them.

I am quite familiar with the Naim models from the 1980s and early 1990s (and if there has been a significant change in design philosophy since then, I haven't noticed it). I had several Naim trade-ins over the years in my former store (which were always very easy to resell), along with some loaners. I also heard them in customers homes and at audio shows. At the time, I considered them "better than average" in sound quality, but never "outstanding". Naim components have some good performance qualities, but they don't do very well in what matters the most to me (and many other audiophiles); retrieving low-level musical information. (You will need good tube electronics for that.)

Naim was special for a while, but only until the late 1980s. They had (and have) excellent current and drive capability, making them unusually stable and versatile. They sounded more natural and dynamic than most solid-state amplifiers. They were also better built and more reliable. Further, Naim has a history of matching their components better than most other companies. A lot has happened since then.

Transistor equipment has become more sophisticated in design, especially with power supplies. The circuits, on many models, are now less complex. The result is that Naim is no longer near the transistor top in performance. While Naim has never been known for providing real "value" (like NAD), they have never charged "crazy prices" for their basic components, and they also have good resale value. If you need solid state to drive your speakers, and the (used) price is right, you can't go really wrong with them.

I would be remiss if I didn't mention that (like Linn) Naim also has a decades long "cult following". These cultists truly believe that Naim are "the best amps in the world", and always will be. I'm obviously not very popular with this group (or the "Linnies"), but their fanatical loyalty make Naim amplifiers an easy resale. Thus, purchasing a Naim component "used" is usually not a serious risk. (7/08)


This is one of the finest 300Bs I've ever heard, and this company actually makes an even better version, the "SE", which I have not yet heard. I originally felt this tube was even superior to the KR 300B tubes that have been my "References" for many years, but I am now having some second thoughts. I would like to perform more extensive A/B comparisons, and this time with experienced and objective listeners. Until then, consider this 300B a serious contender, especially for its typical selling price.

I have found that there are four potential "downsides" with this tube, but I consider only one of them to be serious:

1. They take somewhat more time to warm-up than the KR tubes, or any other output tubes I've had.
2. They are also less sensitive than the KRs, or other 300B tubes I've had. I would guess they are down around 1 to 2 db.
3. I'm concerned that they might have a noticeable high frequency roll-off, at least compared to the KRs.
4. Finally, and I admit that this is pure speculation, or "intuition", on my part, but the 300B/c may sound its best in amplifiers that have a higher plate voltage and/or bias.

Disclosure- I received a small discount when purchasing these tubes. I did not hear them before I purchased them. (12/08)

Radford STA-25 Tube Amplifier

I heard the original Radford STA-25 amplifier in my store for an extensive length of time during the late 1980s, and on several speakers. It was a trade-in. I did not like it, and felt that it was overrated and that its "reputation" was unwarranted. I felt it was veiled, colored, slow and compressed sounding. The best I can say was that it was well built and reliable, but was ultimately mediocre in performance. I haven't heard any of the "reissues" of this same amplifier.


The Original Apogee Loudspeaker,
Mark Levinson and Krell Amplifiers

I recently received this letter from a reader, which has finally provided me an opportunity (and excuse) to relay some interesting experiences that I, and an "associate", had around thirty years ago. Here's the letter, with only some minor editing and my bold:

"...I notice you are perhaps not a fan of large power amplifiers, notably Krell, however this does throw up a slight paradox. Simply that you have the Apogee Scintillas listed as one of your Class A* loudspeakers, which poses the question of what is your most suitable amplifier to drive them? As at present, I have the baby! Apogees ie Calipers, and have long been led to believe that only the Krells were man enough for the job, since they have an impedance of 3 ohms, an even more unfriendly load than the 4 ohms of the later Scintillas! Some people have suggested valve amplifiers, but I think these are the variety which would render the use of lights as meaningless, and could only be used on cold days in winter! I would greatly appreciate your advice on the matters."

*The reader is mistaken. No Apogee has ever been included in my list of "Class A" Reference speakers. The only Apogee I have ever designated as a "Reference" is their Original Full-Range model, which has always been in "Class B" (since it was added in November 1999, for the reasons explained at the end of this essay).

My Response to this Reader

This question brings up a number of subjects I've wanted to discuss for a long time. First on deck: The initial experiences that my associate and I had with the Full-Range Apogee ribbon speaker from the mid 1980s, when it first became available.

Our Early Experiences with the Original Full-Range Apogee

My associate/friend heard the Apogees first. He was vacationing in Florida, and visited a well-known audio store where he knew they were already set-up. The said store was then operated by (the famous recording engineer) Peter McGrath. The Apogees were being bi-amped with two pairs of Mark Levinson ML-2 Class A amplifiers, while the source material were copies of actual master tapes recorded by McGrath. The system was in a dedicated room, and the results were...

My friend was stunned to the point of shock with their performance. He felt it was, by far, the best sound he had ever heard in his life, and he had heard virtually everything out there by that point. Even though more than 30 years has since passed, I still have not heard my friend demonstrate that same degree of excitement for any other component (not just speakers). He became almost obsessed with the Apogees and, of course, I soon caught the exact same "disease" by audiophile osmosis. I was going "crazy" myself, until...

I finally heard the Apogees a few months later in New York City, at Lyric Audio. Unfortunately, I wasn't really impressed with what I heard. At this time, more than 25 years later, I've long forgotten the specific amplifiers and the front-end, though I think I heard a Goldmund turntable. I remember the speakers sounding super clean, fast and immediate, but the listening room was lousy (both small and heavily cluttered), and the sound came right off the panels. There was also no deep bass or dynamic impact. Still, you could easily hear their great "potential", and that's all that truly matters in the long run. So I was still excited and optimistic about the speakers, and I eventually decided to approach Apogee about becoming a dealer for them.

However, this was not to be. Another store in Toronto picked up the Apogee "line" (by then the original Scintilla was also available) on an exclusive basis. As it turned out, this other store was also a Krell dealer, and back then these two audio companies had some sort of unofficial "relationship" between them. I was out, indefinitely, and pretty depressed about it, but fate was soon to intervene...

A potential customer came into my store one day. He had apparently come into some serious money (I think it was an inheritance), and now he wanted to satisfy his long-time fantasy of putting together an "all-out" audio system, even though he was close to being an audio novice. He first asked me what system I would get myself, if money was "no object". Unlike all the other Toronto retailers he had visited, I provided him with an extensive overview of the then current audio world, but more important to him, I mentioned some components that I didn't even carry. This both surprised and impressed him, so he offered me the job of putting together this system for him. I accepted, and I have no regrets at this time, but this "job" ended up being both extremely frustrating and financially unrewarding, though also highly enlightening.

Our Toronto Apogee Adventure of Total Frustration

The "customer", mainly in order to save a considerable amount of money, purchased the Apogees, and a pair of Krell KSA-100 amplifiers, from some store in the Midwest (Ohio?). I forget by now what he purchased from me at that time, if anything, but he also had a Sota vacuum turntable and (I think) a CAT preamplifier. I was soon invited over to hear the preliminary results of this set-up and to see if I could improve on it. I came alone that night and I'll never forget that visit, because I experienced something so amazing, that it has actually never been equalled since then. (And was it ever different from my first experience at Lyric.)

The customer's record "collection" consisted entirely of a few dozen "audiophile" LPs, which weren't very enjoyable to listen to, especially for the umpteenth time, but they were edifying. The one record I heard that night, which I will never forget, was: Symphonie Fantastique on the Reference Recordings (RR-11) label. It was extremely popular back then. The RR is a 45 RPM 2-LP album, with tremendous bass impact* on both the 3rd and 4th sides (they have exactly the same music). Now I had already heard these dynamic sections literally hundreds of times before, on a wide-ranging variety of serious systems; in my retail store, other stores, in my own system, in customers homes and at various audio shows, so I assumed I had heard everything there was to hear. Boy, was I wrong!

*There's even a "legal disclaimer" on the back cover that RR can't be held responsible "for any damage caused by overdriven amplifiers or speaker elements".

The degree, intensity and quality of the mid-bass focused impact was something I had never heard before in my audio life, or since that evening for that matter. The most telling description, and example, of my gut reaction to what I experienced that night is this:

Since I had heard this particular dynamic section so many times, I was not only thoroughly sick of it, I also knew, exactly, when the next great impact would come. So after the first shock, I assumed the next shock(s) could not come as a "surprise", because I now knew when and what to expect. Well, they still did! Each impact, in its turn, was one more shock, without any diminution. Even when I braced myself for the next impact, I was still stunned by it. To be honest, at the time, I didn't think what I was hearing had been even possible to achieve with an audio system. And it wasn't just the pure degree of the impact I'm talking about, the quality of the impact was also amazing. If I had to use one other expression to describe what I heard, it would be this: "Awesome and Scary".

Unfortunately, that was the only sonic "highlight" of the evening, though I was to hear another "quality" that was also unprecedented. During the other sections of Symphonie Fantastique, and all the other records that were played (Jazz at the Pawn Shop, Amanda McBroom, Opus Three "Test Record 1" etc.), the sound was mediocre, at best. The sound was dry, mechanical and dead at medium and especially low volumes. Even worse, and the most unforgettable negative aspect I heard; The voices and the instruments, as well as the entire image, was as thin, literally, as wallpaper. I even used the descriptive term "wallpaper" to the customer that evening. He agreed with my assessment, good and bad, and decided to move the entire system to a dedicated room, in the basement, before my next visit a month or so later.

I looked forward to my next visit, and this time I came with my "Apogee obsessed friend", who was hearing them for the first time since his memorable Florida trip. Well, my friend's excitement didn't last very long. In fact, he was profoundly disappointed by what he heard, because the sound, believe it or not, was even worse than what I had heard during the previous visit. In short- The sound was even deader than before, while the amazing impact had virtually disappeared. I can't say even one positive thing about what we heard that evening.

For the record, the customer, who was easily influenced by either the last person he talked to, or article he read, was by then really into the "dead room/live room" magic formula, which was all the rage at the time. I tried it myself, but found it didn't work, and quickly gave up on it. The customer didn't, and all he received, for all of his efforts, was the "dead" part. In fact, I had heard dozens of budget systems (Spica/Nad/Rega etc.) that sounded much better than what I heard that second evening. Incredibly, the system's sales tax was more than those budget systems. So, after undiplomatically informing the customer of our negative evaluation, which he sort of suspected himself, we decided to then try some different amplifiers and make some serious changes to the "dead room". This would all happen a few months later, and those quarterly visits would then become the norm for the next year or so, until my friend and I (plus one or more of my employees) eventually gave up.

The Comedy Ends

To finish this story, we tried the Ray Lumley M-100 mono amplifiers, which did much better than any of the Krell amps with the midrange and high frequencies. Despite our objections, the customer purchased (traded for) an assortment of increasingly powerful, and expensive, Krell amplifiers. The room was also periodically changed, along with the phono cartridge and various cables. This process continued until the customer finally (I assume) ran out of money. The result of all of this effort and expense...

The sound did improve somewhat, though hardly in line with all the effort and expense, but at no time was the performance even close to being really "special". Needless to say, it also never approached what my friend heard in Florida. Over time, our visits became less and less frequent, until they stopped. Then, a year or two later, the customer called to inform me that he had sold most of the the system, with the Apogees going to someone in Japan.

CES Chicago 1990- The Apogee/Krell Room "Incident"

Shortly thereafter, I heard a rumor that Apogee may be looking for a new Toronto dealer. Actually, by that time, I was no longer that excited by the line, since the original Apogee speaker, their one truly great model, was no longer available, and I wasn't really that impressed with their current models. Still, I decided to visit their showroom at the Chicago 1990 CES (which turned out to be my last CES visit for 14 years), and see if something was possible between us. I never did become a dealer, but I did have a highly memorable experience while in their showroom, which is relevant to this discussion about Apogee and, much more importantly, Krell electronics.

Apogee had an extra large room that year, with seats for around two dozen people. They were playing the Divas (I think), their "flagship" model at the time, and the most expensive Krell electronics, both amps and preamps, were driving them (I can't remember the source). The room was large enough to have a private "tent" in the back, where the man in charge, Jason Bloom, served food and drinks and talked with his best customers. I sat in the second row, almost directly behind Leo Spiegel, the designer of Apogee, as well as Bloom's partner and father-in-law. There were maybe a dozen people in the room, all quietly listening to the system. Thanks to Bloom, we heard a constantly changing variety of interesting music, some of which was familiar to me. (I can't remember any of the musical selections.)

Eventually, Bloom, coming out of the tent once again to change the music, noticed me. He knew me from previous years, when I virtually begged him for the line, but he always politely turned me down, insisting that Krell dealers had first priority, and I wasn't a Krell dealer, in the past, or then. Bloom turned down the volume, greeted me by name, and asked me what I thought of the sound of the system. With everyone in the room now looking at me, I gave him a generic, non-committal response: "It was good". Bloom frowned, and apparently disappointed with my lack of enthusiasm, pressed me, in front of everyone, to tell him exactly what I "really felt". Now I felt that I had no choice but to be totally frank.

So I replied with the best of my modest diplomatic skills: "I hear some good things, but I'm mainly hearing the Krell electronic sound, which I don't like". Then I added (since I was in for a penny, so why not a dollar): "I wish I could hear the speakers with different electronics." Bloom was silent for a few seconds, as his face quickly turned red, and then he shouted at me: "That's bullshit, bullshit! You don't hear any Krell sound because Krell doesn't have a sound!" With the room then so silent you can hear a proverbial pin drop, and with my heart pounding, I calmly replied that "Krell does have a sound. It's dry, gray, lean, electronic and mechanical. I hear it every time, including now, in this system." Bloom shouted "Bullshit!" one more time, put on some music, and left the area to go back into the rear tent, theatrically closing the flap door after he entered. Like a tennis match, everyone's eyes then returned to me.

Then, something really surprising happened, which made the entire incident worthwhile, and totally unforgettable, for me. Shortly after Bloom was out of view, Leo Spiegel turned around with a smile and offered his (huge) hand. As we shook hands he told me: "Thanks, I agree with you". Next, before I could reply with more than a simple "Thanks!" to this most unlikely source of public support, I felt someone behind me tapping my shoulder. I turned around, and another person offered his hand to me. We shook hands and he said: "I agree with you too". I looked at the name on his show badge: Clark Johnsen* (now with Positive Feedback) of "Absolute Polarity" fame. A few other people also thanked me for stating my opinion and not backing down. Then, somewhat embarrassed by all the attention I was getting, plus seeing no other reason to stay, I decided to leave. As I reached the door, I felt someone tap my shoulder. Turning around, it was Jason Bloom. He apparently wanted to talk to me one more time.

To my (second) great surprise, Bloom was now calm and polite! He graciously thanked me for coming and giving him my honest opinion. He also told me he hadn't made up his mind about what he was going to do in Toronto, but promised he would take my store into serious consideration. We shook hands and said goodbye. That was the last time I ever saw Jason Bloom alive. Tragically, he died in 2003, a man still in his prime. Thankfully, we parted on good terms.

*I met Johnsen again almost 14 years later, at the 2004 CES show. He told me that I was somehow familiar to him. When I recalled the details of the Bloom/Krell/Apogee incident to him, he remembered ("aha") it all himself.

Our Next (and Last) Krell/Apogee Experiences

A year or so later (early 1990s), my Apogee friend met a rather wealthy fellow who had put together a truly serious system: The most expensive Krell electronics, both amps and preamps, plus the Apogee Diva. He also had a Versa Turntable, and a large, dedicated listening room, with superb acoustics. Unfortunately, this person had more money than experience, so my friend decided to assist him out of "audio mercy". I eventually became involved myself with this project, and I ended up visiting this person's home a number of times over a year period. The first time I visited, despite the owner's almost manic enthusiasm, the sound was so bad ("dead"), that it appeared that one (or more) of the components was actually defective. So, we decided to try out some different components. After we were through, all the Krell electronics were replaced with tube electronics*.

First up were the power amplifiers. Once again, a pair of Ray Lumley M-100 mono amplifiers replaced the big Krells. The customer bravely ignored the dire warning of his record dealer*, and was amazed at the improvement he received from the Lumleys. Of course, this result wasn't much of a surprise to my friend and I, but the next component comparison proved to be highly enlightening.

*A well-known record collector/writer/dealer, who at the time was selling this person "Original Pressings" from the "Golden Age" (Mercury, RCA, Decca, EMI, etc.), at incredibly inflated prices, and who had also recommended the Krell components, actually warned him that any tube amp would literally "blow up" the Divas. I'm serious!

This person also had the "top of the line" Krell preamplifier, the (four-chassis) KRS Balanced. At the time, it was one of the most expensive preamplifiers in the world ($10,000). If that wasn't enough, an earlier version had received rave reviews from both Harry Pearson and David Wilson (of Wilson speaker fame) in The Absolute Sound. Despite this person's skepticism, my friend next brought over his own Counterpoint SA-9 phono preamplifier to directly compare to the big Krells. The Counterpoint had a few minor modifications, mainly coupling capacitor replacements, along with some judicious tube rolling (my friend's specialty). We all really looked forward to that "shoot-out"; the best tube preamp versus the best transistor preamp! However,...

It didn't take long to pick "the winner", and it was unanimous. The Counterpoint "wiped the floor" with the Krell. There was simply no comparison between them. The difference was so huge*, the Krell's owner was almost in shock ("How can this be!?"). More to the point, he ordered the Counterpoint SA-9 the very next day (our listening session was on a Sunday).

*The Counterpoint was much more natural, less electronic and mechanical, with a noticeably lower sound-floor, and with all of the additional musical information which comes with that critical advantage, as well as having more natural body. Any Krell sonic advantages were negligible (deep bass) and musically superficial by comparison.

Still, after all the improvements we made, which went beyond the electronics changes above, we could never get the Divas to compare overall to my (modified) Wilson WATTS and Entec SW-2 subwoofers, or my friend's (modified) Martin Logan CLS, with Tympani IV bass panels. Within a year or so, the Diva owner, out of sheer frustration, and after hearing our systems, switched to dynamic speakers, and was even a speaker manufacturer himself for a couple of years.

Some Apogee and Krell "Loose Ends"

While I was never either an actual Apogee or a Krell dealer, I still had some trade-ins from both companies. This was during the late 1980s and in 1990. I took in a few Apogee speakers, including the Duetta and the Stage, but the only trade-in that I considered important, and which inspired a serious project, was a pair of the original Scintillas, with the ultra-low impedance. Of all the Apogees, the Scintilla seemed to me the one that was the closest in design, and potential, to the original "Full-range" model. (The Diva was closer only in sheer physical size, and not in design and execution.)

I was so excited by this opportunity, that I actually brought them into my own apartment (which was two floors above my store). For a year or so, I, my Apogee friend, my employees and even some experienced and enthusiastic customers, all made a serious effort to get the Scintillas to really shine. We tried every appropriate amplifier in my store during that period, and that was a lot of different amps. In addition, we also used every suitable amplifier model we could borrow. Sadly, while I remember getting pretty good sound on occasion, we never reached the level where it could be honestly described as "formidable", let alone "magical". I/we finally gave up after a year and I sold them. The person who purchased them was NOT among our small group of "optimizers". I didn't miss them, and neither did any of my associates. Meanwhile,...

I also took in a Krell preamplifier and amplifier in around 1990, the first (and only) Krell trade-ins I ever had back then. I can't remember the preamplifier model, though it definitely was not their "top of the line", but I do remember the power amplifier. It was the KSA-50. The preamp was mediocre. Virtually all of my tube models (MFA, Audible Illusions, Counterpoint), and even some transistor models (Dolan, Perreaux, Spectral), outperformed it, when we made our routine (A/B) comparisons. I sold it quickly thereafter. I decided to hold on to the KSA-50 for a little while longer though, for the purpose of completing a thorough "examination".

I tried it on a wide variety of speakers, but the only area where it truly excelled was in the bass. It had another positive trait though, it was not "offensive", in the sense of adding objectionable and irritating sounds, but it did subtract a noticeable amount of musical information, which other amplifiers, even some that were much less expensive, would pass on. The Counterpoint SA-12 and SA-20, to give just two examples, were noticeably superior to the Krell in overall performance. Finally, a customer who had fantasized about owning "a Krell" for years, and who couldn't contain his lust for the KSA-50 whenever he had visited the store, received a call from me that his dream could now be realized. I had promised him "first-refusal", for the obvious humanitarian reasons, and also because he had previously purchased the matching Krell preamp from me.

Looking back, it's possible that he was the happiest customer I ever had in my 20 years of retail. In fact, I can still remember him leaving the store with his Krell to this day. I wish I had a picture of the ecstatic expression on his face. (Ironically, he was almost hit by a car as he crossed the street, because he couldn't take his eyes off the carton in his arms!)

Final Conclusions and Advice

I have now posted all the major experiences that my associates and I have had with the Apogee speakers, and the main electronics we used to drive them. The (numerous) "minor" experiences we had are not worth recalling (or reading). They are simply repetitive and add nothing to what has already been posted. There are enough anecdotes above, along with consistent outcomes, for a reader to make their own judgments, but here are my final conclusions and general advice.

Apogee Speakers- There were a number of good speakers made by Apogee, but there was only one that was potentially (though rarely in practice) "outstanding". That was, of course, the "Original Full-Range" model. Almost all of the above focused on turning the "potential" of this speaker into "reality". It was only done once to our* satisfaction, when it was driven by two pairs of Mark Levinson ML-2 amplifiers (and I wasn't even there). The bass panel, by itself, was also driven successfully with the Krell KSA-100. So my advice is self-evident:

If you want to put together the finest Apogee system that any of us has ever heard*, you must find both a pair of the original Full-range models, in good working condition, as well as two pairs of the ML-2 amplifiers in good condition, plus all of the additional components (crossovers etc.) which may be necessary for optimization. This information can be found by doing the research on some of the Apogee enthusiast's websites.

*They are in Class B, rather than Class A, because of the extreme difficulty of amplifying them, plus the fact that I never heard them at their best and the now 25 year gap since that first amazing listening session in Florida.

I would be prepared for the fact that it may take years to find all of these components. As for temporary "compromises", the only one I can suggest would be using the appropriate Krell amplifiers for the bass panels, while waiting for the second pair of the Mark Levinson amplifiers. This alternative may adversely effect the image, and even the tonal balance, but at least the dynamic qualities of the speakers should remain intact. Other than that, my only other suggestion is to find an amplifier equivalent to the ML-2 which is made today. That means an amplifier which is truly "Pure Class A" and with almost unlimited current. The end result of this search must be an exceptional amp, possessing an output of over 650 (high quality) watts into a .3 ohm load. Good luck!

Krell Electronics*- I think it's obvious that I am not enthusiastic about any of their components, including their "top of the line" models. Ironically, one of my associates feels that one of their earliest models, the KSA-50 discussed above, was one of the best (most natural sounding) amplifiers that they ever made. My advice concerning Krell components is simple:

If, despite all the above, you are still seriously interested in a Krell component (which is understandable considering their unique reputation, build quality, easy resale, appearance, rave reviews, successful utilization of a particular technology, speaker flexibility and performance, either directly experienced or assumed to be present), then I would:

Immediately go to Audiogon (or Stereophile) and make a search for "Krell" in their Used Components For Sale listings. When I last made my own search (March 2007), I came up with more than 125 Krell components "for sale". The selection was amazingly broad and encompassing. Large discounts from the normal retail prices were routine**. Even more encouraging, it's obvious that with such a large market for used Krells, there will be new replacements inevitably joining this list on a daily basis. In short- You would have to be arguably reckless with your limited funds, or wealthy beyond caring, to purchase any Krell component "NEW", at the typical retail prices.

*Personal Disclosure- I admit I've been offended by the use of the name "Krell" since the day I found out about it. "Krell" originated from the (now classic) 1950s science-fiction movie Forbidden Planet. In the movie, which I've loved since first seeing it as a child, "The Krell" were a hyper-intelligent race of beings, 1,000,000 years more advanced (in every manner) than the people on earth (us). I realize that the manufacturer was simply attempting to "honor" his fond memory of the fictional Krell, but I still view it as display of arrogance. How the Krell, who were almost divine, managed to all die off, is the film's ultimate mystery. The surprising and profound answer to this question is eventually revealed at the end of this must-see movie. (Sadly, inspirational brand names don't effect a component's performance.)

**I always advise buying components "used" if they're from any of the "major" electronic manufacturers: Mark Levinson, ARC, CJ, Musical Fidelity, Classe, Cary, Naim, Rowland etc. It makes no sense to me to pay the full retail price when there are so many used models easily available on-line, and at huge discounts.

Mark Levinson- I have added the Mark Levinson ML-2 amplifiers to the list of Class C Reference Amplifiers, primarily because they are the one and only amplifier that any of us ever heard bring out the full potential of the Apogee Full-Range speakers. In fact, without that one (overwhelmingly positive) experience, the Apogees would be most accurately described as only a "theoretical" speaker, completely impractical in "real life", with its potential only possible to realize "on paper", or in the person's imagination.

Finally, please keep in mind that most of the experiences I've related with the Apogees occurred more than 20 years ago. The analog sources of the day (especially cartridges), were noticeably inferior to today's models. From my optimistic perspective, I think this means that the unforgettable sound my friend heard in Florida, so many years ago now, could be even further improved upon today. However, someone else may feel that the other components back then, including even the ML-2s, may have also been masking problems that are inherent with the Apogee's ribbon design. This is a personal judgment call. My main goal, with this lengthy post, was to help an interested reader make that call.


Conrad Johnson Preamplifiers and Power Amplifiers

I once received this letter from a questioning reader:

"CAT, ARC SP-10 and 11, SA-5 and 5.1 --- GREAT CHOICES for ultimate tube preamps from the past. But no Conrad Johnson listed along side these? I don't understand. I think the Premier 3 preamp is a DEFINITIVE contender for the same level of performance as these other great preamps. Please consider this."

My Response

I was once a CJ dealer during the early 1980ís. I have a lot of experience with all of their models from back then, both the amplifiers and preamps. I have made a Reference of the phono stage of the Premier 3 (along with the Premier 2, PV-1, PV-7, PV-2 and PV-5) for many years now.

I donít consider any of these models as a Reference preamplifier, because I don't think their line stages are competitive (especially the noisy PV-1), along with the fact that their circuit boards back then were cheaper, and deteriorated faster, than the ARC models. I realize some of the CJ preamps may still be a better match in certain systems, especially those using inferior digital sources and/or transistor amplifiers, but I found their general (overly warm and full) "character" something I couldnít ignore in most of the phono/tube oriented systems I had, both in my store, and in my own home.

Itís possible that a modification could have addressed this character problem, but I never got around to it. The stock, polystyrene coupling caps (in the Premier 3 and PV-5) were apparently better than the competition, and I didnít know what else to do at the time. From a strictly personal preference, during that period, I used an ARC SP-8 (purchased used) in my own system (or the Precision Fidelity C-9 or C-7A), even when I was a CJ dealer. I canít overlook my own previous preferences, or I would be dishonest with myself.

This same, highly noticeable, "CJ warmth", is also why I haven't made a Reference of any of their power amplifiers in the past. Though, when I think about it, the CJ amplifiers are still good enough (and very important in my personal audio evolution), to deserve some extra attention. So, I'm going to end this undeserved neglect, and discuss some of my history with their early models; from the original MV-75, the first CJ amplifier I ever heard, to the later Premier One.

The 1980s CJ Amplifiers-Some Experiences and Anecdotes

My First CJ Experience

The first time I heard a MV-75 was back in 1981, at the apartment of my (then new) friend, Israel Blume, now the designer and builder of Coincident Speakers (who was at that time a lawyer). He was using the CJ on a pair of stacked Quads (with stands he had built himself), and the sound was simply superb. It was very natural, highly detailed, ultra transparent and cohesive. I had never heard the Quads sound that good, and I had already owned two pairs of them myself by this time.

But something else (much more important and influential in the long run) happened to me that same day: After I had described an element of the sound that was particularly impressive, Blume informed me that this quality (the separation and layering of the musicians) had only developed after he had modified the MV-75 by replacing its stock coupling caps with some better versions that he had found. Needless to say, this experience changed my audio life.

My Own Store-As a Dealer

Within a year, I was selling the CJ line myself, in my own newly opened store. I picked up virtually every CJ model, including their huge Premier One, which was then the favorite amplifier of Harry Pearson, who had gone crazy over it. Personally, I had also sold my Dynaco Mk. VI amplifiers, which had been a major disappointment for me, and replaced them with an Audio Research D-150. The ARC was another rare and sought after amplifier, and also the Premier One's main competitor at that time for the title of "The Best Amplifier in the World". Incredibly, I had both of these amplifiers at the same time! Which one was better?...

There was no clear-cut winner when I made the comparisons back then. This was done several times, with a good number of serious audiophiles, some of whom travelled many miles to hear both of these amplifiers at the same time and at the same place. However, most of us had a preference, and that was for the ARC, which of course came as a surprise, since we had all read the rave review by Pearson. The CJ had several sonic advantages for sure, but the D-150 was more neutral, faster and cleaner. It disappeared better, or, in other words, it was less noticeable.

I later modified the ARC with better coupling caps (with the help of a friend), and the performance gap with the CJ was even more noticeable. The result of all the ARC/CJ "shoot-outs" was another important turning point for me, and also many of my friends and customers, because the "HP/TAS Halo" was now found to have some serious holes, which we couldn't ignore, since we had experienced it firsthand. In short- We were now becoming our own "Gurus", which is a necessary step in the audio maturity and evolution of all serious audiophiles.

Eventually, both my own ARC D-150 and the store's Premier One were sold. I also dropped the CJ line after the new Canadian distributor raised the prices (I had previously purchased the CJ line direct from the factory). After that (1985/6), the only CJ equipment I had in the store were trade-ins, which were quite common until I finally left Canada in 2001, many years later. However, a long-forgotten and discontinued CJ amplifier had one more unexpected part to play in another important experience I had. Once again, it involved a direct comparison in my store, with several customers present. It's a little lengthy, but the final results were surprising, and even saddening...

The Second Retail Act-A New Generation of Electronics

When I went back into retail in 1996, I decided to carry just one serious transistor line, Pass Labs. I only had 3 of their models, the Aleph 3 and 5 amplifiers, plus the Aleph L line stage, which was actually passive at unity gain and below. The Aleph L and 3 were my main transistor demo components for several years, and, as could be predicted, numerous comparisons were made between them with both various transistor and tube models.

Back then, the Aleph 3 was a "hot item", receiving a rave review in Stereophile/April 1997 (still available on-line). The reviewer, Muse Kastanovich, felt it was "the finest power amplifier I have ever had in my system". He even wrote that, based on the other Class A amps he had heard, "the Aleph 3 deserves an even higher rating than Class A". Shortly thereafter, customers came to my store from all corners to hear this amazing amplifier. It only made sense, Stereophile had made an incredible claim; a transistor amplifier that was even better than the finest of tubes! And the Aleph 3 didn't even cost that much ($ 2,300). In fact, most good tube amplifiers were much more expensive. I would have even been excited myself, but I wasn't. The reason was...

Sometime in the Fall 1996, I (and a few of my friends) had taken the time to extensively audition the Aleph 3 in my own system (actually one amplifier per channel-biamping). We soon discovered that it was not the equal of my modified Jadis JA-80 (which did cost a lot more money). I later compared it to other (relatively) expensive tube amplifiers, such as the Atma-sphere M-60 II, and in each instance the Aleph 3 fell short. It did outperform every transistor amplifier I had compared it to (though not by much), so I still felt the Aleph 3 was a positive development, and an important component in the audio hierarchy.

In the end, selling the Aleph 3 was not a pleasant experience for me. Despite the Stereophile review (and others), and many potentially eager purchasers, most of the customers backed off once they found out that the Aleph 3 was not the equal of the top tube amplifiers (let alone better, as they had been led to believe). Worse, I had the unpleasant job of informing them of this "bad news", either through auditions in my showroom, or from conversations over the phone. Many of them suspected this reality beforehand, already having noticed Stereophile's growing predilection for gross hyperbole, but even worse was to come, though it was highly edifying in the long run. This is where the CJ MV-75 enters the story, almost by accident actually...

Enter the Old CJ MV-75

This particular MV-75 was a real early version, at least 15 years old at the time, and manufactured before any factory upgrades had been made. I took it in as a trade on an earlier trade-in, a big Levinson amplifier. The MV-75 was working well, and the owner, on my advice, already had a technician replace the coupling caps. The replacement caps were "OK", and definitely better than the stock caps, but far inferior to the better types then available.

Well, one day a group of customers came in from another city, traveling a long distance to my store just to hear the Aleph 3. They were prepared to buy one on the spot, but first they wanted my personal opinion (as a fellow "tube lover") directly to their faces, and then make some comparisons. As usual, they were seriously disappointed when I relayed the experiences we had in my own system (and with other more expensive tube amplifiers). Then one of them asked about the CJ MV-75, sitting on a display shelf.

He wanted to know how it would compare to the Aleph 3. I told him that I didn't know: For whatever reason, I had never directly compared the Aleph to an older generation tube amplifier. Maybe I had thought it would be an unfair comparison, since the Aleph 3 was more than 3 times the cost of the CJ, and the CJ also hadn't been played for weeks. Still, I immediately decided to oblige them, and, further, I was curious myself. Could a 15 year old tube amplifier, now considered "obsolete" by most audiophiles, actually compete with the most modern and acclaimed transistor amplifier in the current market place?

The Aleph 3 was already "warmed up", so we played it while the MV-75 warmed-up in another room (with load resistors in the speaker banana jacks). The customers were surprisingly impressed with the Aleph 3 (driving the Coincident Visionary Reference). I could actually notice some of them starting to second guess my opinion of it (maybe Stereophile was right!). After 45 minutes or so, and a variety of music, all CDs, I put in the MV-75, choosing the same CD* we had just heard, to make the comparison as easy and relevant as possible. The music was early Baroque, with a variety of original instruments and voices. It didn't take long to get a reaction...

Out of "Retirement"-One Final Victory

I'll never forget the CD or the male voice we heard that day (Cut 2-Stradella-Esule dalle sfere*). This may also still be true of the other listeners in the room. In short- The CJ MV-75 was much more natural and real than the Aleph 3. To such a degree, that we were all stunned to the point of total silence, outside of some spontaneous grunts and a "My God". We all realized that we had experienced something important, and it would take some time to digest it. In a haze, and by rote, I made some other comparisons, demonstrating the Aleph 3's superiority in bass control, but by then the customers didn't care. They thanked me, and left. As they walked up the steps from my basement store, I could hear them agreeing that the long trip was well worth it, despite the results.

As for me, I knew that any remaining "enthusiasm" I had with the Aleph 3 was forever gone. I sold very few of them after that day. I even wondered whether I had deliberately averted such a comparison in the past, just to avoid experiencing such a result. This comparison bothered me more than I could have predicted, and it still does, even today. I actually felt betrayed. I found the final results not just disappointing, but almost "grotesque". I couldn't get past the depressing implications of what we had heard. Feeling the need to talk to someone...

I later called Israel Blume, who had designed and built the speakers we had used. I told him exactly what had happened, including the vintage and the "modification" of the MV-75, an amplifier he was obviously intimately familiar with. He wasn't surprised (he rarely is), and we both agreed that this was just further proof that even some of the most basic tube amplifiers, long overlooked or forgotten, most selling for "peanuts", were still superior in the most important musical areas to anything using transistors, no matter what their cost and design. It's this type of experience, and there were many others like it, which I remember when someone ignorantly claims that I'm "biased" against transistor electronics.

Of course, we can't forget the Stereophile "review". Why was it so wrong? Was it common incompetence or typical cronyism, or even both? In the end, it doesn't really matter. The "bottom line" is: Stereophile is full of crap far too often, and an audio disgrace, period. They can't be relied on, then and now, and that's all that does matter.

Finally, you can find both of the above amplifiers on Audiogon for under $ 1,000. However, if I had to make a choice between the two Aleph amplifiers I used to sell, I slightly prefer the Aleph 5 to the Aleph 3. Their basic performance and quality is about the same, but the Aleph 5 does have more control, weight and sense of power. It can also be used with a greater variety of speakers. It will obviously cost a little more, but I feel the extra investment is worth it. (Unfortunately, neither of them are "beauty queens".)

Meanwhile, on a positive note, I'm ending my past neglect of the CJ MV-75. It's going into the "Entry-Level Amplifiers", at least with a simple modification (installing modern coupling caps). It's only fitting, considering its relative performance over 3 decades now.

*Musica Oscura-Bringing Light to The Unknown-Sampler Disc- 280826

Conrad Johnson Addendums

I received a letter from Bill Thalmann, of Music Technology, who is located in Virginia (see contact information and Link below). Bill specializes in repairs and upgrades of CJ components, and also does SACD upgrades. Since he was CJ's Technical Director for 22 years (1978-2000), he should be an expert at this type of work.

5418 Port Royal Road
Springfield, VA 22151
FAX 764-0079
CELL 703-501-9419


I can't let the subject of early Conrad Johnson amplifiers end without first relaying the experiences that one of my closest friends (also an "associate") and I had with his Premier One amplifier. My friend first had the amplifier modified to accept KT-88 output tubes. (This was mainly accomplished by changing some resistor values, and quality, in the biasing circuit.) He was just beginning...

While on a modificaton "kick", he decided to also have the coupling caps changed to high quality polypropylenes (.47uf/600volts). Not stopping there, he also converted the amplifier to Triode operation, as well as changing the critical resistors, IEC jack etc. Ironically, after all this effort and expense, he found the amplifier too bulky to live with, and ended up trading it for a pair of Manley Retros. So, let's now address the big question: Was all the work and cost worth it?

Yes, indeed! The Premier One's performance and sound were literally transformed. Its highly noticeable colorations, which made it (in)famous, were basically gone. It was also much more transparent, delicate and immediate, cleaner and faster, and even more dynamic, despite the reduction in measured power. It was even more reliable. Overall, it was one of the most successful modifications I have ever experienced. And the final cost wasn't excessive, especially if the owner is already planning to replace the output tubes in the near future.

To summarize, here's my best memory of my friend's modification of his Premier One;
1. Conversion of the circuit to optimize the use of KT-88 output tubes with wire-wound resistors*
2. Conversion from pentode to Triode operation*
3. Coupling caps changed to high quality polypropylene (or even Teflon caps for extra money)*
4. Film capacitors added in parallel to both the B+ power supply and the decoupling capacitors
5. Critical resisitors replaced with better versions
6. Power cord replaced with heavy duty IEC jack
7. RCA inputs changed to XLR inputs
8. Internal wire changed to VandenHul
9. Bias trim pots changed to film types

*Most noticeable changes

CONRAD JOHNSON PREMIER 8 POWER AMPLIFIERS-I've been criticized by more than one reader that I haven't given enough attention and respect to the Conrad Johnson line of electronics, especially their more recent models (I was one of their dealers in the early/mid 1980s). We did hear a number of them at the 2004 CES, but none of them sounded special to us. However, you generally can't make a negative evaluation from audio shows, because of the inherent variables in practice, which are almost impossible to overcome. Fortunately, fate came to our rescue.

In the last couple of months, one of my associates received a mint pair of the (recently discontinued) Premier 8 power amps to audition in his home system. He was able to compare them to a number of amplifiers already References on this website. The speaker he was using was the Coincident Total Victory II, totally broken-in, which I've also heard in-depth and have already placed in Class B of our Reference speakers. It is both highly accurate and highly revealing, plus it is sensitive and an easy load for most power amplifiers. This meant that the comparisons would focus on amplifier "quality Vs. quality", since the Premier 8's extra power would not provide an advantage in this particular instance. The results...

The Premier 8 was the worst amplifier of the bunch, by far. The superior amplifiers included not only the Canary Audio CA-339 and ASL Hurricane, but also the Altec/Tutay 1570, and a number of SET designs. The CJ was, in my associate's words; "heavily veiled, rounded, bloated, rolled-off, soft and distorted". He felt it was the kind of amplifier that could sound "pleasant" as long as the speaker required its power and/or the listener never heard or was bothered by its problems. While it may still outperform CJ's older and even more colored and veiled models, it is not a Reference for those audiophiles who are seriously looking for "real live sound", for better or worse.

Now, according to my associate, these are not "bad amps", but amplifiers using these "standard" designs (pentode tubes/push-pull circuit), with one or two exceptions, are now one (or more) large step(s) behind the most "modern" thinking and designs, particularly those which have successfully implemented "old technology"; meaning hard-wiring, simple circuits and direct-heated triodes.
Bottom Line- They're no longer competitive to the top (or even just better) contemporary models in performance.

"On the other hand"- Another one of my associates heard the CJ ART linestage and was very impressed with it. He told me that it was the finest and most neutral component he's ever heard from Conrad Johnson. He also preferred it to the Audio Research Reference line stage, which he felt was lean and a little dry. From my perspective, I advise avoiding linestages, but if I didn't, the ART would be near, or even at, the top of those we've heard. (2006)




CAVEAT-Please be advised that the readersí letters posted on this site are solely the opinion of that reader and may not necessarily represent or reflect the opinions of Arthur Salvatore. These letters furthermore, are not to be taken as being endorsed by Arthur Salvatore. They are posted because they may be edifying, thought provoking or entertaining.


845 DHT OUTPUT TUBES For some time now, a veteran reader has been sending me information, along with his observations, about the production of "all-out" 845 DHT output tubes currently being manufactured in China. Here is his latest communication:

"I just finished three hours of listening to 845 tubes on my deHavilland 845-G amps. The NOS tubes were supplied by a friend who helped me listen. What we listened to were a pair of NOS RCAs, two pairs of NOS Uniteds (each pair with different internal structure), a pair of the original metal plate Shuguang (845C) and a pair of the new metal plate Shuguang (845M). We played a variety of music - solo voice, male and female, acoustic guitar, violin concerto, and rock. The rankings ended up as follows:
1. United
2. 845C and RCA tied
4. 845M
5. United with glass rod coming down from top to stabilize inner workings

Despite my high hopes, the 845M did not sound as good as the 845C. The good side of this disappointment is that the 845M has 115 watts of plate dissipation compared to the 75 watts of the 845C. 845s have traditionally had about 90-100 watts of plate dissipation. Thus, these new tubes should last much longer than lower rated tubes. Also, the internal structure of the 845M should be less prone to mechanical failure. This has been a problem with the 845C.

The 845M sounds similar to the Shuguang graphite plate 845B. The internal structure of the 845M and 845B look very similar except for the substitution of the metal plate for the graphite plate. The 845B is not a bad sounding tube. Neither is the 845M. They just do not sound as good as the best NOS. If you did not have NOS tubes to compare the 845M to, you would not know what you are missing.

What you are missing with the 845M is detail, clarity and a three dimensional quality of the instruments within the soundstage. We are not talking night and day differences, but differences that are noticeable on a high resolution system. On a mid-fi rig all the tubes would probably sound very similar.

My guess is that the 845Ms were released without sufficient testing on high resolution systems and that the tubes will be withdrawn from sale until further designs are tested."

Further- This same helpful reader sent another e-mail on this same subject a few days later. Here it is:

"Since my last e-mail to you I have been exchanging e-mails with Mr. Luo Min of Super-TNT, the retailer and force behind the Chinese 845M vacuum tubes. Per Mr. Luo, the yield rates on the original 845M (now known as the 845C) are too low to be profitable. Thus, the need to develop the new 845M. The new 845M has high yield rates and sounds better than the 845B. However, the new 845M does not sound as good as the 845C. The problem according to Mr Luo is the material used for the anode. The best sounding materials do not have a high enough dissipation rate and the materials with the best dissipation rates don't sound good. Mr. Luo thinks they have designed an acceptable compromise, but the factory needs to buy new equipment to make the parts.

What all this means is that the 845C is still the best sounding Shuguang manufactured 845. However, it does not last as long in the field as other 845 tubes due to its lower dissipation rate. The new 845M sounds worse than the 845C, but better than the 845B and will last longer than average in the field. Sometime next year a new new 845M will be released which should have the reliability of the 845M and the sonics of the 845C.

I guess Rome was not built in a day. Stay tuned for further details, but don't hold your breath."

DEHAVILLAND 845 AMPLIFIER- It didn't take long for another reader to send me his observations concerning a potential Canary CA-339 competitor, mentioned prominently above; the deHavilland 845, which is considerably less money. I felt his information is relevant, especially for present owners of the deHavilland. Here it is, with slight editing:

"With regards to the Canary 300Bs versus deHavilland 845s, I have never heard the Canary's, but I do own the deHavilland 845s. I just put in a pair of the new Shuguang 845B tubes. The difference between the stock Shuguang 845s and the new 845Bs is not subtle. Mr. Ed Sawyer has an interesting review of the 845Bs on Audio Asylum.

Comments by other Asylum members would indicate that the Shuguang 845B sounds better than the Kron 845. In addition, the Shuguang factory is supposed to release, by the end of 2004, metal plate 845s. So you might want to drop a note to your Canary correspondent to not sell his deHavillands quite yet. It would be very interesting if your Canary correspondent could try the new 845Bs and report back to you. These are exciting times for tube lovers."

Personal Notes- I agree with this reader; these are "exciting times for tube lovers". I visited the deHavilland room at the 2004 Las Vegas CES, and I was impressed with the natural sound I heard there. They were using 1960s pre-recorded tapes from Columbia. Their 845 amps are also much less expensive than the Canarys. Finally, I forwarded this letter to the "Canary correspondent" as this reader advised.

845M DHT OUTPUT TUBE- Here is the latest information about this interesting tube from a reader; slightly edited;

"You had asked that I keep you posted on developments with the metal plate 845 vacuum tube (845M) from the Shuguang plant in China. Mr. Ed Sawyer, who wrote the nice technical review of the 845B, has posted an excellent technical review of the 845M at the Tube Asylum, January 20, 2005.

Yesterday, I received a matched pair of 845Ms from the first production batch. Today, two friends and I spent a number of hours listening to the 845M and comparing it to the Shuguang 845B, to NOS RCA and to NOS United on my deHavilland 845-G SET monoblocks.

Based on our comparisons, the RCA had the biggest sound stage, but was the least dynamic. The United was the best all around performer. The 845M was the most dynamic, but we felt it emphasized the treble to a slight degree. The 845B had a more even frequency response than the 845M, but we felt the 845B was more HiFi-ish in sound and the 845M more natural in sound, even with the rising top. We all preferred the 845M over the 845B. The margin of difference between the 845M and the 845B is about the same or slightly less than the difference between the stock Shuguang 845 and the 845B. Two of us preferred the 845M over the RCA due to the 845M's superior dynamics. The other person preferred the bigger soundstage and silky smoothness of the RCA.

After the listening sessions we did play some heavy metal LPs, loud. At high volumes, the 845Ms seemed to be running out of steam. No clipping, but they just could not play as loud as the 845Bs. The manufacturer did state that the 845M has only 75% of the power output of the 845 and 845B. Based on our experience it would appear to be true.

So, the wonderful world of vacuum tubes continues to improve with the resurrection of the metal plate 845 which has been out of production since the 1930s. Who would have predicted this five years ago." (2/05)

TOM EVANS LINEAR A STEREO AMPLIFIER-A reader, who has considerable experience with some of the best amplifiers being currently made, sent me this letter about the Tom Evans amplifier. I would normally be more sceptical, but his observations and judgment have been pretty accurate so far. You can read more about his experiences on Audiogon. Just do a search on the "Canary CA-339" to find him. Here's his letter:

"Have you had a chance to hear the Tom Evans Linear A stereo amp yet? If not, you really should. 25wpc from 4 parallel EL84s per channel driven by op amps (!), and it totally smokes my uber-tweak (Audion) PX-25* in every musical and sonic category. I'm convinced this is a revolutionary amplifier."

*According to this reader, the Audion PX-25, in turn, had previously outperformed the Canary CA-339 on the reader's FAB Audio One speakers.

Personal Note-I have no experience with the Tom Evans amplifier. I've liked the EL-84 (pentode) output tube for years, and have used it extensively in my own system (VTL Tiny Triodes), but it's almost unimaginable for me to conceive it outperforming a high quality SET amplifier (I've already made a serious effort to do so, and failed). You have to keep an open mind though, because the EL-84 may be the finest pentode tube ever made, and with the right design (parallel and not push-pull) and execution, who knows its ultimate audio potential.

The same reader sent me a copy of a letter he sent to an "Internet friend", in which he describes the Tom Evans amplifier in more detail, and with plenty of direct and relevant "comparisons". I found it very interesting. Here it is:

The Second Letter

"The (Tom Evans) amp has about 50 hours on it now, and seems to have settled in. I really haven't heard any changes in its sound since Christmas. As it burned in it got more even-handed, tonally speaking. It sounds more unified, it lost a bit of upper-mid prominence which gave it some initial impressiveness. In its place is a sense of wholeness, effortlessness and an even further increased transparency that just gives me shivers. It now sounds tonally identical from top to bottom - it has the same level of clarity, dynamics and musicality from the top of the cymbals to the bottom of the organ pipes.

I had another audio buddy over yesterday. He has big JM Labs Electra floor-standers, an 80 wpc Unison hybrid and a Linn LP12. Not exactly chopped liver. After an hour of listening, his comment was "This is simply outrageous!" So far the amp has had rave reviews from everyone who has heard it, no matter their level of experience with hi-fi.

I just finished playing it against my PX-25 amp using the same Vibe preamp, because I wanted to give you a report of how the two sound head-to-head.

Frankly, there is no contest. In comparison the SET sounds impressionistic, as though it had wrapped a nice thick layer of friendly around the sound. It is too warm, with enough missing detail to compromise its transparency, it doesn't have the clarity or the dynamics - even the microdynamics that SETs excel at are outdone by the Evans amp.

The Linear A is much more immediate and live sounding, the images have cleaner edges (the PX-25's images sound fuzzy in comparison), and transients are much faster. The Evans amp is much faster overall, and gives a more coherent picture of the music than the SET. As a result of course the treble is cleaner and more realistic and the midrange is more open and accessible, but even the bass is better resolved as well. And needless to say, every nuance of a musician's performance - every variation in bow pressure, slight shift in tempo or modulation of phrasing - comes flying out of the speakers with an intelligibility I've never heard from another amp.

This is in comparison to my custom-built Audion PX-25 that is stuffed with over-the-top components and cost me $18,000 US. In my system that amp in turn had eclipsed three solid-state amps (SimAudio 4070, Sugden Au51P and a new Nelson Pass Aleph J), a pair of Coincident MP300B monos, a pair of deHavilland 845Gs, a pair of Wavelength Tritons ($12K+ amps in their own right) and a pair of Canary CA-339s. But the Linear A has killed it stone dead.

I'm still in shock over how good the damn thing is.

By the way, keep in mind that I'm using it with a Vibe line stage. I tried it with my Bent Audio Noh TVC. A couple of other friends who were present remarked that the system sounded broken, and were mightily relieved when I put back the Vibe. So be aware that the amp will let you hear exactly what the preamp and source are doing upstream."

Personal Notes- All I can say is; If this reader is right, then this amplifier is indeed a "breakthrough", or "revolutionary", as he claims in his first letter. I'm not going to hide my innate skepticism, plus my gut fear that this is "too good to be true", but wouldn't it be great to finally have a real alternative to the SET designs? Time* will answer any doubts and obvious contradictions with past results, but, for now, this amplifier can only be described as "exciting news" for serious audiophiles. (It has 25 watts per channel.)

There is also another amplifier from Tom Evans, the Linear B, which is mono, and has twice the power (55 watts). Hopefully, someone will get a pair of them into their system and report back. HiFi+ did a review of them recently. (Their one potential downside is their more complicated circuit.) There is a link to the Tom Evans Audio Design website below, and also in the Link File. Unfortunately, there is not much information on the site, just the "basics".

*2006 is looking like the "Year of the Amplifier", just as 2005 was the "Year of the Phono Cartridge". (12/05)

SET AMPLIFIERS- A reader sent me the letter below about an interesting 300B amplifier by Electra-print, with no coupling capacitors. This can be done with the use of an inductor to ground (as in this case), or an inter-stage transformer (like the new SET amp from Coincident*). Electra-print is also the source of the output transformer used in the "Frankenstein" amplifier discussed at length above (October). Here is the reader's letter, including his links, with only very slight editing:

"There are designs that use no capacitors in the signal path. I provided a link to a 300B DRD amp that I own. It sounds great only on the best recording. Otherwise you hear all the flaws in poorly recorded stuff. (When music is recorded as an instrument or voice in isolation, and then mixed together, that is exactly what it sounds like.) Also a pre-amp can be made without caps too. Not trying to promote these... I must say I have heard a lot of expensive equipment and I am always amazed at how little they do for all the money. Speakers in particular!"

*Personal Note-The new 300B SET amplifier from Coincident, discussed above, arrived late, and is only now being broken in. I'll have more on it in the New Year. The Electra-print amp also sounds exciting, based on both its design and the proven output transformer expertise of the manufacturer. The reader's enthusiastic observations only add to that excitement, especially since I'm probably not bothered by the "flaws" as much as he is. (12/05)

ASL HURRICANE AMPLIFIER-A veteran reader sent me another simple modification which should improve the performance of this Reference amplifier. Here it is, with some slight editing, and don't forget the usual warnings and caveats:

"...I know that we have beaten the Hurricane horse to death in the last two years, but I have a simple modification that has made a substantial improvement in my pair...

The Hurricane has one resistor (for each output tube) in the signal path between the input tubes and the output terminals: (R19-R26). These 8 resistors (per channel) are easily accessible, and worth about $ .08 each. I removed and replaced them with:
Holco 1K ohm/1 watt, 1% resistors (metal film), costing $ .50 each.
They are available from Handmade Electronics (

The mod was cheap, and only took 4-1/2 hours start to finish. This is a very worthwhile easy mod, and it adds a really nice touch of refinement to the amps, but one needs to be comfortable with a soldering iron, heat shrink tubing, have a schematic and be able to understand it. The details...

The resistors are easy to find. There are eight (8) resistors in each amp, and all connect between Pin 5 on the KT-88 tube sockets, and one terminal on the large green square capacitors. (Looking from the bottom, counting clockwise from the locating notch, the fifth pin past the notch.) This is the only resistor running from the big green cap to a pin on the output tube socket. Be sure to insulate all leads with shrink tubing.

If you are an experienced DIYer, with some practical electronic kit building under your belt, this should be a piece of cake. If not, find a competent technician to install the resistors for you.
Caution: Unplug the amplifier 24 hours before opening it, to allow the power caps to discharge (touching a charged cap can ruin your day!).
Disclaimer: I am not reasonable for damage, mistakes, or results, good or bad."

Further Hurricane Modification from the same Reader- "I just installed V-Caps (.10 uf) to bypass the power supply capacitors. Boy, was this worthwhile, better results than I had imagined. Recommended."

ASL HURRICANE AMPLIFIER- Here's a letter from a true expert on this excellent, and now popular, high powered model. Once again, as in the letter above he refers to, it focuses on the resistors found inside the stock Hurricane.

"I would like to add my 2 cents in about the Hurricanes... (See the reader's letter above.) The resistors he speaks of are the Grid Stop resistors. While everyone has their favorites, I feel the better resistors to use in this location are the Riken Ohm pieces. Yes they are a bit more pricey, but are among the better choices for this application. If a Hurricane owner uses his amps in Triode mod, I would also recommend replacing the 100 ohm Screen Grid resistors with the Riken as well.

While we're on the subject of resistors, I have one more highly recommended upgrade. The 10 ohm Cathode resistors, used in the stock Hurricanes, are junk for the application. Upgrading these to the 5 watt Mills non-inductive resistors makes for a great improvement. In my modifications, I also change and upgrade EVERY resistor in the input stage of the amp, but this is for another day.

I guess we will have to see what the latest rendition of the Hurricane brings us. They have redesigned this amp, new look and circuit with better transformers, and is due out in August."

Bill Baker
Response Audio
112 Carl Street
Endicott, NY 13760
607-785-3440 or 1-888-785-9773 Till 6pm Eastern

Personal Notes- I'm confident that Bill's upgrades will work out. However, I only recommend experienced modifiers making these changes themselves. This is the first time I've heard about this "redesigned" Hurricane. Let's hope this isn't an excuse for the price to unreasonably jump as well.

Further- Bill later got back with some more relevant information about the new Hurricanes. Here it is:

"It is estimated that the price will go up about $1k. While I have not yet heard them, I feel this may be a justifiable increase due to the new output transformers they are using as well as providing a balanced input as standard. We all know the new cosmetics would not justify any substantial increase in price."

CELLO COMPONENTS REPAIR - A reader sent me a short letter describing his positive experiences when he had his Cello components recently repaired. Here it is, with very slight editing (my bold):

"Some months ago, I e-mailed asking for your assistance in locating someone to repair one my Cello amplifiers and the Goldmund Reference turntable. In one of the e-mails, I mentioned I had located a former employee of Cello, Paul Jayson, that now works at Viola Audio Labs (203.772.0435), and that I was going to send the amp and power supply in for repair.

You had asked that I give you some feedback after the repair was complete regarding the service. Have the amp & power supply back (1 of 4) and hooked up in the system. Superb! Couldn't be more pleased. The repair cost was reasonable and Paul's knowledge of the Cello equipment is probably unmatched.

I would highly recommend his services and hope this referral will be of help to others."

Paul Jayson's e-mail:

Personal Note- Eventually, I will try to put together a dedicated file with technicians and companies who have good track records for repairs and modifications, especially for rare and esoteric components, where the owners may have particular difficulties finding "locals" who can do the work.

ATMA-SPHERE M-60 MK.II- These excellent amplifiers have been on the Reference list since this website began 7 years ago. There's been some changes since then, and I just received some of the details from Ralph Karsten himself, the designer of Atma-sphere. So, from "the horse's mouth", with some minor editing and my bold:

"I thought you should be brought up to date on a few things...:

The amps you reviewed come from about 1999-2000. We have made some improvements (to say the least) since then. Resistors have been added to the output section to improve harmony between output tubes. There have been several iterations in this regard since 2000. As of this time, we have increased the effectiveness of the resistors by a factor of 10- for this and other reasons, distortion is reduced by about 95% over the model you heard. Getting rid of distortion means more low level detail and smoother sound. We also get the side benefit of radically improved tube reliability.

The current itereation is the M-60 MkIII, which in essence is the same circuit you heard but with the refinements above, plus 50% more filter capacitance in the output section, and 3 times the capacitance in the driver supply. Two types of Teflon coupling caps (including the V-Cap) are optionally available, as well as Caddock resistors (custom built for us) and a power supply filter cap boost option. Bias is automatic- DC Offset is manually adjusted. This allows you to temporarily compensate if you have a minor tube failure. The meter is now a VU meter, which doubles for setting the DC Offset control.

The current amps are thus more reliable, easier to live with and sonically are a transformation over the edition you heard (older units can be fully updated with warranty reactivation)."

Personal Note- I haven't heard this model, but you can almost bet your life it will be noticeably superior to the Mk. II version that I am very familiar with. My confidence is based on my many years of experience with Atma-sphere's different models and updates. My associates' numerous and similar experiences simply confirm mine. So I would not hesitate purchasing this new model, or updating earlier versions, if you have been satisifed with them, and the cost appears reasonable to you.

Meanwhile, a veteran reader sent me his observations concerning the MKIII. Here it is:

"I just read your post on the AS M60 MKlll. Ralph is bang on. I had the Coincident 300b amp for a while. When I moved to the AS M60 MKlll, the improvement was not subtle. The problem was all those woofers (in the Total Victory II). When I upgraded to the AS MA1's, everything got a whole lot better. When listening to Aimee Mann on SACD (on the lowest setting of my Placcette passive), everything is there, very romantic. When I listen to Pink Floyd, Led Zepplin, Dire Straits etc. on my turntable, I am able to shake pictures off the wall. I can listen to Aretha Franklin soft, or I can listen to Annie Lennox at ear splitting levels. Try Nine Inch nails 'Closer', and feel your insides compressing. You need to hear the TVll's with the MA1's..."

Personal Notes- I'm going to try to follow this reader's advice next year, since this year's visit to Toronto is fully booked. The Atma-sphere amplifiers have always been excellent matches with the Coincident speakers, due to those speakers' very easy loads. The Coincident models with multiple woofers should be especially good partners, because the Atma-sphere's (OTL) designs have superb bass (tight, impactful, extended and detailed), when they see easy loads.

Further- Here's another letter from another veteran reader of this website, with more information and observations about the latest changes to the Atma-sphere amplifier line (my bold):

"...I was prompted to write you after reading the recent letter from Ralph Karsten that you posted under "Readers Letters" for September. I wish to add my endorsement of the Atma-Sphere Mk.III upgrades as an owner of an upgraded pair of MA-2s.

I own a pair MA-2 amps that were recently upgraded from Mk.II to Mk.III status; the same changes apply to all the amps in the Mk.III upgrades, so I'm assuming what my wife and I hear in our amps will be substantially similar to what one will hear with the M-60 or MA-1. For us, the improvements have been only just short of stunning. Bass reproduction is deeper and even more well defined and articulate, imaging in both width and depth is improved, and the superb resolution is now accomplished with an overall improvement in relaxed naturalness ("smoothness" if you will) that I'm inclined to attribute to an even lower level of lower distortion. Some of these improvements (bass extension, soundstaging and mid-range "smoothness") were immediately apparent after only 20 hours or so of break-in. However, it was not until the 200 hour point that the top-end came into it's own with the new capacitors finally breaking-in.

And, the upgrade comes with a complete "as new" factory warranty: a standard practice for Ralph whenever any of his products are returned for upgrade to current factory specifications." (9/06)

Personal Notes- This is further confirmation that this upgrade is great news for both current and prospective Atma-sphere owners. Also, it now appears that I'm pretty "safe" after "betting my life" in the first "Personal Note".

QUICKSILVER AMPLIFIERS- I received this informative letter from a reader in May 2005. It made me realize that I should have made a Reference of the (early) Quicksilvers from the beginning. Here it is, slightly edited:

"After reading your description of the Quicksilver amps I have a few points to make. The original 8417 models clearly out performed the KT-88 versions. Even stock they are amazing amps. One caveat that most people don't realize is that this amp can't really drive any load at all. To really hear it in all its glory it must be used with very high efficiency speakers. If it's challenged at all it falls apart and sounds unrefined. Use it with a 95 (dB) or above high impedence speaker and it comes to life. It fits your description of low level detail retreival at extremely low listening levels. I listen to a pair on a single driver pair of older hammer dynamics speakers, which are 97dB efficient and this is an amazing combo for no money. Many who have heard it have compared it to systems costing 20 times more. I was very surprised at the sound myself. I only stumbled onto the combo by accident. I use these amps with an autoformer. Due to their extremely high gain, they are well suited for use with a passive autoformer. This is by far the best Quicksilver amp ever made. The earlier 5 tube versions are the most desireable. These amps are in a different league than some of your Class C amps, but must be carefully matched with speakers to hear what they can do."

Personal Note- My/our experiences and observations are very similar to this reader. I remember the 8417 having the better midrange, while the KT-88 version was more powerful and had better bass, so it could be used with a greater variety of speakers. I don't remember ever hearing any Quicksilver with a really high efficiency speaker (above 92dB).


This letter is from a reader who appears to have quite a bit of experience with tube amplifiers. There's only some minor editing (my bold):

"...I wish to add my two cents for what it's worth. I have listened to dozens of racks of equipment owned by myself and others. I also was good friends with a used high end dealer, who allowed me try whatever I wanted in my home.
1) The Atma-sphere amps are excellent, but have one serious problem. They put a tremendous stress on the tubes causing them to arc, and if not periodically tested will blow your speaker drivers. Trust me on this one.
2) The Luxman 3045s have a serious problem. They originally came with proprietary tubes that are almost impossible to replace. Luxman subsequently came out with a mod that converted the amps to KT-88s. Which, depending on the skill of the local technician, may or may not work. Again, my friend had both versions, and it was a night and day difference. I would suggest looking into the Airtight amps. They sounded excellent when I auditioned them a few years back, and have a similar sound.
3) Finally, I am curious about your site's opinion on Sonic Frontiers. I own an SFS-80 amp and frankly don't see eye to eye with you. Of course, taste plays a factor. I don't like the Power 2 amps at all. I honestly was not impressed with the rest of the Sonic Frontiers line, but the SFS 80 was an exception. It is a particularly tube sensitive amp, especially in the choice of 6dj8 tubes. I can see your point about leaness when compared to Quicksilver amps, which are too sweet for my taste. But switching from 6550's, which tend to be lean anyway, to EL34's, warms the sound considerably.
...I do urge you to warn your readers about the relibility issues with the Luxmans and Atma-shperes."

Personal Notes- Most of the reader's above "issues" have already been commented on within this website, but I'll repeat myself anyway, plus reply to what's new.

1. I was an Atma-sphere dealer for years. I don't remember having any problems with the amps I had in the store (or after they were sold), and there were several of them. Mind you, all of them were the M-60 Mk. II, though with different parts quality. I have heard, but never owned, one of their larger models, which do have considerably more output tubes. A friend had a pair of their original models, with 12 or more output tubes per channel, and he did have some problems with blown tubes, but this was in the early 1990s, so I donít know how relevant that is today.

2. I'm aware of the Luxman amp problems, though not from direct experience. I remember hearing at least one pair of them in my old store back in the 1980s. The only person that I can remember owning them, a customer who I didnít know too well, didnít have any problems. However, Iíve read about other peoples' problems, which is why I put a prominent Caveat in the description of the Luxman in the Vintage file. I canít do more than that. I've heard some good things about AirTight amps, and heard them at audio shows, but I don't have enough experience to make a relevant comment about them.

3. I've never heard a Sonic Frontiers component that I liked, with the one exception of the last CD player they marketed, the SFCD1 (it was actually manufactured by someone else). I realize that one or more of their tube amps may work well in a fortuitous situation, but there are a large number of better amps out there, many for less money, so I wouldn't bother searching for it. Finally, the Quicksilver amps can be improved with better coupling capacitors. I still prefer them to anything from Sonic Frontiers.

Another Observation from an Atma-sphere Owner

This letter from a veteran reader, who owns two Atma-sphere amplifiers, confirms the reservations of tube reliabiity first mentioned by the reader above, though with a somewhat "happy ending":

"I have both the M60, and MA1. I drive the (Coincident) TVll's pretty hard. I have blown tubes on many occasions. Once while listening to Nirvana at stupid levels, I blew most of the tubes on the right channel. I replaced the tubes, did the proper warm up, and continued listening. THERE WAS NO DAMAGE TO THE SPEAKERS."

Wavelength X-2 Cardinals

This was a small part of lengthy letter from a reader:

"I just got a pair of Gordon Rankin's latest and greatest Wavelength X-2 Cardinals and they're fantastic! Yes, even better than the modified Golden Tube Audio 300b monos! Tight deep bass, excellent natural sounding mids with extended highs. Fast with lots of dynamics. Imaging and soundstaging is superlative."

I asked this reader: "Do your Golden Tube amps have the same modifications as mine?" His reply to me was:

"(I) sold my Golden Tubes 300b, but yes they essentially had your mods. Wavelength X2's are as good or a slight step up IMHO."


I've never heard of these amps, but the same reader who liked the Wavelength Cardinals (in October above), went "crazy" over them. So have a number of other audiophiles who post at Audio Asylum (SET). Here's the letter with some slight editing:

"...the absolute finest amps I've heard recently are being made by Don Allen of Phoenix, Arizona. He makes them all: 45, 1626 Darlings, 2A3, PX25, 300b's, EL 84 all for very reasonable prices ($1700-2000 for a stereo, $2200-2600 for monoblocks!!!). His $1700 2A3 amps blew Gordon's Wavelength Cardinals out of the water!!! Better resolution, better dynamics (yup, that's right!), better frequency extension.

Go to the Audio Asylum's SET page and type in "Don Allen"......see what people are saying. The guy is a genius! His trade mark is a lightening bolt on the front of his amps that is backlit at night! (you can get the amps plain as well....) He uses good stuff (James, Tango, Tamura iron; NOS caps and tubes)...This guy amkes amps that high end manufactureers can only dream about. They're that good."

Personal Notes- I read some of the enthusiastic experiences posted on the SET Asylum, and can verify the reader's observations. The prices appear to be very reasonable to me, with little risk involved. There is no contact information or website URL. To contact Allen, you must make a request to a SET member, such as Todd Kreiger, and he will send you the information directly by e-mail.

I later asked this same reader for more clarification on the Don Allen amplifiers, especially how they compared to the best from Wavelength, and here is his reply to me:

"Are they better than Gordon's? Well.......that's saying a lot if its true. What I will say is that Don Allen amps are sonically just as good, including a comparison to Gordon's Jupiter 50s and 45s which most people feel are Gordon's best amps. BUT remember, Gordon's amps cost 4-10 times the cost of Don Allen's amps! So if considering a cost/performance ratio in any comparison, its not even close!

This isn't my opinion, its the opinion of a growing number of people as you can see on the Audio Asylum. I suggest you contact Todd Krieger, a highly respected Audio Asylum member and audiophile, who has several of Don's amps and knows Don quite well. You can find Todd's moniker (his name) on the Audio Asylum in the SET section.

The nice thing about Don Allen is that he doesn't simply go out and buy super expensive parts and throw them together, claiming to make a world class amp. Instead, he very carefully researches the synergy between a wide variety of components and transformers, usually with the help of 6-8 local audionuts in the Phoenix area. In the process, Don may select less expensive or more esoteric iron and other components, NOT based on price but on performance and design criteria.

Once Don and his band of merrymakers agree that a prototype amp (or preamp or phonostage) has "spoken to God", Don offers the amps to the public. The end products speak for themselves. I'm not 100% sold on his signature "lightening bolts" (he offers amps without them) but I'm willing to look past the bolts and enjoy the music."

Personal Note- I endorse the method Allen uses to design his electronics, particularly his reaching out to the local Phoenix audiophiles for help and confirmation. This is a proven method to get outstanding results and avoid mistakes. The more I hear about Don Allen's amplifiers, the more I am intrigued about them.


"I have played my FiX 2a3 amplifier on the Living Voice speakers, and there is no way that amplifier can drive those speakers, not even close. It simply breaks up on just about every type of music. It cannot even really get started.

You may wish to get some feedback on the dnm speaker cable. The best I have heard by a long shot. Also, Omega Speaker systems could be added to your SET friendly list. Audio Zone gain clone is the amp you reference when speaking of the 47 labs model. Canadian built and half the price, at 45 watts it uses the same chip set as the Japanese model. I have one coming in for audition and will let you know the results."

Personal Notes- I have no direct experience with the Living Voice. Maybe it would work with a 300B amp, though that solution doesn't appear hopeful based on this reader's observations. I, and my associates, have some experience with the Audio Zone. We were impressed, but my associate, who heard it in his own system, didn't feel it equalled a good SET design, which shouldn't be a surprise. However, if it is competitive with the 47 Labs, which is probable, than it would be a relative bargain, considering both its power and price advantages.

Counterpoint Amplifier Upgrades by Michael Elliot-Latest News

I received this letter from a reader who may have his Counterpoint hybrid amplifier updated by Michael Elliot. I still don't have any personal experience with any of these upgrades, but based on anecdotal evidence, a lot of the customers have been very happy with them, despite their cost. This is the latest news about the upgrades of their popular hybrid amplifiers, which I always felt offered excellent performance and value for the money. (I was a Counterpoint dealer back when they were sold new.) There's some minor editing and my bold:

"I've been considering having Michael Elliot upgrade a Counterpoint SA-100 for me, and in the process have been scouring his site, asked him a few questions, and of course repeatedly referred to your entry on the Counterpoints. In the process, I've noticed a couple of small points that you might consider updating or adding that I wanted to pass along.

The first is that according to Elliot's web site, he now cannot get the MOSFETs for the SA-12, SA-100, or SA-220, as well as the SA-20 you mention. The Natural Progressions use a bipolar transistor, so they aren't affected. He does mention several option for repair for all these SA models, including a near $300 replacement with a used pair of MOSFETs pulled from a working model he is upgrading for another customer. These are warrantied for 90 days. You can also get them shipped to have a local repair or self repair done for about $80 less.

He also suggests a different MOSFET as a substitute, although he clearly states that he has not tried the parts himself, and is only making people aware of the possible alternative. Of course, you can have the amp upgraded using his basic upgrade (which includes a different circuit board, a different curcuit, many improved passives). The prices seem to range from about $1,100 to 1,650 (lower powered models are at the cheaper end).

(I suggest that you) make the readers aware of a couple points about the Elliot upgrades. The first is that, while the Natural Progression models are all superior stock to their SA progenitor (e.g., SA-100 becomes NPS-200), the upgrade possibilities are far superior for the SA models. Elliot can improve some of the capacitors, resistors, and transformer with the Natural Progressions, the SAs can be improved well beyond what he can do for the Natural Progressions. As Elliot puts it in his FAQ section 'A Basic NP amplifier (upgraded SA-20, SA-220, SA-12 or SA-100) surpasses ALL the factory-stock NPS amplifiers by a long shot. An SA amp that has received even only the Basic upgrade will surpass a fully-upgraded NPS amp by a smallish margin. An SA amplifier that has received the Premium or Premium Gold, or Premium NP upgrade is in a different class altogether, completely surpassing the NPS amplifiers.'

So, if you are considering getting a Counterpoint with the intention of having Elliot upgrade it, you should look for the SAs rather than NPS models (with the added benefit of being cheaper to get used).

The other is that the Elliot upgrades to the SA models make it essentially a different amplifier, as they replace the circuit board with a new and different circuit board based on a different circuit, albeit by the same designer. For instance the SA-100 has two 6DJ8 tubes and three coupling capacitors per channel in a three-stage circuit, uses the MOSFET output, and employs 20dB of feedback (output stage isn't in the feedback loop). The upgrade is a much simpler circuit (single-stage), with only a single 6922 tube and a single Dynamicap coupling capicitor per channel, uses a bipolar output transformer instead of the MOSFET, and employs no feedback.

He also offers a "high sensitivity" alternative using a 6SL7 tube for those who need more gain because of lower preamp output (<4 volts rms [12 volts peak-to-peak] amp input needed) or for those who use a passive preamp (he says it will work with as little as 1 volt input). There is also an alternative "low sensitivity" option for those that would prefer a 12SX7 tube (needs at least 4.3 volts amp input).

Everything I have heard leads me to believe that there is a substantial improvement for a relatively modest investment compared to other alternatives (at least it seems worth the risk), but the point is that you are essentially keeping the chassis, the heat sink, the transformer, and the power supplies from the old amplifier and creating an entirely different amplifier. Whether this elevates its performance along your criteria, and perhaps pushes the 'upgraded' amp into a higher class remains to be heard, but the changes 'seem' to enhance things in the ways you approve. I'll let you know what my ears tell me when all is said and done."

Personal Notes- This is really good news, though somewhat surprising. This means you can go out and find an older Countepoint Hybrid, which has the blown Mosfets, but everything else working well, send it to Elliot and get back an amplifier that's actually better than the later Natural Progession series, even when the NP model is itself modified. Considering the total costs involved (the blown amp should be peanuts), this could be quite a good value.

Still, I wish Elliot would also start manufacturing new amplifiers himself, even in small quantities. The way things are now, and have been for years, only the audiophiles who are upgrading their older Counterpoints are benefiting from Elliot's latest thinking and innovations. That is a real audio tragedy.

Further- Amazingly, it turns out that my above "wish" has already been granted. Here's a follow-up letter from the same reader above:

"(Michael Elliot) actually has started a line of new equipment. He has a couple hybrid amps, and is working on a preamp. He is selling it under the name Aria, Ltd., which can be found at I haven't really looked into these, but they seem to be an update of the NPS amps, including ways that he can't update either the SA's or the NPS's with his mods. There is a 100 watt and a 350 watt amp available in several configurations (high & low sensitivity input, basic & premium), and the 100 appears to be upgradeable later to the 350. They start at about $4,500. I don't know anyone who has heard them, but he does have a 2-week home trial program where you can return some of the amps for a full refund."

Personal Notes- This is all good news. I already created a link to the website below. Also, 6Moons now has a lengthy and glowing review of the Aria 100 watt hybrid amplifier posted on their website.

Antique Sound Labs Hurricane MK. II

Here is the most recent correspondence from Bill Baker of Response Audio about the new version of this now well-known and popular amplifier:

"The new Hurricane MKII has been released. Retail price is $ 6,200 pair and several changes have been made. The transformers are now suppose to be of the highest quality and the circuitry has also been enhanced. The chassis has now emerged into a new vertical design. It comes standard with triode switching (between triode and pentode) as well as balanced inputs. I will let you know my thoughts on any sonic enhancements. Details can be found here:"

Magnavox 93 Series Console Vintage Amplifiers

A reader sent this letter about a vintage amplifier I've never heard of before. This could be a true "diamond in the rough" scenario. (My bold)

"Just thought I'd throw you a bit of a curve-ball vis-a-vis amplifiers. I've owned solid-state, push-pull tube, SETs and whatever else over the past 30 years, never with total satisfaction. For the past year I've been driving my wonderful Spendor 9/1's with a minimally modified and upgraded Magnavox 93-series console amp (PP 6BQ5's) from around 1961. I've never owned such a dynamic, natural-toned, effortless-to-listen-to amplifier before. Instrumental timbres, transients and dynamics are life-like, bass is subterranean and controlled (really!), highs are sweet and natural. Cost me all of $99 on eBay plus $200 or so in parts! Ask your friend (Tom) Tutay about the design of this amp (he knows.)
Might be just the ticket for jaded, bank-account-depleted audiophiles!! (1/07)"

Clayton Audio Amplifiers

I've known about these amplifiers for years, but I have totally overlooked them on this website, and even in my e-mail correspondence. Fortunately, a helpful reader reminded me about them, so it's time for me to make some amends. Now, at least one, and probably two, of my associates has heard them pretty extensively, and were very impressed, though the audition(s) were not structured in a manner that would allow a Reference designation. Still, when you add this to the rave reviews by both Bound for Sound and International Audio Review*, you have a potentially good-news scenario: A growing accumulation of consistent and objective observations and opinions, all from experienced listeners, and all of them highly favorable. Accordingly, these amplifiers should be considered a serious option for all those audiophiles who are open-minded about, or would actually prefer, solid-state electronics.

Yes, the Claytons are all transistor models, but they're very well made and thought out, and fairly priced. In fact, while still built in the U.S. (St. Louis), they sell for a fraction of the price of most of their transistor competition. Unfortunately, Clayton was lax when it came to Internet Protocol, and they allowed their domain name to be lost, but another website has the relevant information on it:

The bottom line for me- If I couldn't use tubes, for whatever reason, the Clayton line would be near, or even at, the very top of my list of the most suitable replacements (along with the Tom Evans amplifiers, but they're, sadly, way overpriced).

*Both of these reviews can be read on-line. Critically, both reviews claim that the Clayton amps are superior to the best of those from the "major" manufacturers (Krell, Levinson, Classe etc). Meanwhile, don't forget that neither of these magazines accepts any advertising. The mainstream press has mainly ignored this line, and certainly has never even hinted that they could actually outperform the much more famous (and expensive) amplifiers that they routinely promote.

The Counterpoint NPM Amplifiers

This is a rather lengthy reader's letter which I felt should still be posted. It has information and observations I've never seen before. I initially attempted to edit it, just to make it shorter, but I soon felt something would be taken out of context in the process. So here it is, basically unedited, because of its length. (I don't have the time to even add bold.)

"I bought my NPMs from an Ebay auction, sold directly by Michael Elliott, the original designer of the amps. Upon winning the auction, I requested the basic upgrade, which according to Mike, would bring the amps to within 90% of the Aria WT amps in terms of sonic signature, and the same degree of musical pleasure as the WTs. The amps arrived in cartons, cosmetically they were in shape I would best describe as fair, with more visible scratches on the side and front panels than I expected.

Upon power up with initial listening, the NPMs do remind me of the specimens I heard back in 1992 1993, buttoned down, very neutral. Compared to the Counterpoint SA220 and NPS400 I had before they are definitely many many classes above them. Definitely kicks the butt of any Audio Research amp I have owned (VT150 VT200 VT130 Classic 150 Classic 120, with the last 3 modified with Infinicap SETI and Auricaps).

Piano solos (Chopin Scherzo Nr.2/Yundi Li/DG and Chopin Valse Op. 34 No.1/Alexandre Tharaud/Harmonia Mundi, Schubert Impromptus/Zimmerman/DG) : very smooth and even, great dynamic contrast and decay but never a really harsh note like other solid state amps. Initially the Chopin Scherzos sometimes push the envelop of evenness to borderline hard, swapping the original Sovteks to JAN Sylvania 6922s alleviated the problem, but reduced the clarity a bit. It probably has something to do with the age of the Sylvanias. I almost forgot to mention the most important, piano music from these amps have BODY to it, something I thought only well-made tube amps, and certain Jeff Rowland amps in the transistor world, could do. I'd personally still like them to have more sparkle and air. At the same time, I still find that very occasionally a transient note in track 16 of the Tharaud/Chopin CD would go borderline overboard.

I have had solid state phobia for some time due to the unbearable steeliness of violin sound from most solid state and even hybrid amps. My fear was allayed when the system played Glazunov Violin Concerto/Gil Shaham/DG, Sibelius Violon Concerto/Midori/Sony, and Vivaldi's Four Seasons/Ozawa-BSO/Telarc. The strings were well textured, and as an added bonus, the woodwinds bloom and have a tube like presentation to it, much like the sound from my other reference amps, the VAC Phi 70 monos and my old BAT VK60 monos. However, occasionally I do notice a slight thinning and coolness to the tone in tracks 7-9 of the Gil Shaham CD as well as various passages in the Sibelius violin concerto.

Part of my solid state phobia has me very sensitive to the often exaggerated and annoying sibilant sounds. No worries with the NPMs. Female vocals like Alfee/Nightclub-Patricia Barber/BlueNote-Premonition, Georgia on my mind/Here's to Ben-Jacintha/Groove Note, and Desafinado/Ana Caram/Chesky) simply shine with the NPMs, lush, smooth, and warm.

Choral pieces often give amplifiers a challenge due to the demands for both low level detail and the ability to hold sonic stability during the loud passages. The sound stage showed very well with Now the Green Blade Riseth (Kornet Har Sin Vila)/Proprius records, with the louder passages showing no smearing or hardening. Misa Criola/Ariel Ramirez-Jose Carreras/Philips throws a somewhat laidback presentation, reminding me of my very first audition on the NPMs with this CD way back in 1993. While the soundstage was stable without any smear, and the choir was smooth with no wows, I could use more air and perhaps the very last bit of detail.

I kept wondering if that can be tweaked easily by replacing the driver tubes or coupling caps. I understand that the dynamicaps are Mike Elliott's favorites but I have an inclination towards the now pretty rare Infinicap silver SETIs. After playing the amps for 2 months or so I started experimenting with Infinicaps (now with the red coat which makes them look identical to the Dynamicaps) with little audible difference, then the obliggato caps from diyhifisupply in Hong Kong, which warmed up the sound a teeny bit at the expense of top end. Somehow I never liked the overly "fast" sonic signature of the Dynamicaps.

With the more complex pieces like Firebird Suite/Stravinsky/Telarc, Beethoven Choral Fantasy/Ozawa-BSO/Telarc, etc., I appreciate the neutrality and control of the NPMs. It's all about control, from the low registers all the way up to the top end. While I do miss the low level detail offered by my most favorite tube amps, the dynamic stability from the NPMs while maintaining body and musicality makes them quite enjoyable. I have heard solid state amps like the Pass X350.5 which offers both bass oomph (even more so) and stability in playing the grand passages. While driving a friend's Avalon Ascent IIs (which I use to own), the NPMs bass pales compared to his X350.5. Even when driving my Avalon Eidolons, the NPMs still exhibit occasionally an ever so slight tendency to dryness when loud complex passages are played.

My dilemma with many amps (especially solid state ones) has been that I miss the utmost inner detail and in an attempt to compensate, I crank up the volume only to realize that I had them playing too loud, resulting in the breakdown of soundstage and thinning of the instruments. The NPMs never had their soundstage breakdown, but somehow I feel that when playing music with a lot of dynamic contrast I am either missing something or I am cranking the volume just a tad too loud.

Regarding my affinity for top end air and the utmost detail and low level finesse, perhaps I am too used to the very spacious presentation of my reference VAC Phi 70s which has 4 300Bs per side, and to a lesser extent the Bat VK60 Monos. Maybe I am asking too much tube sound from a pair of hybrid amps. With that, I left the amps idle and went back to my long term reference the VAC Phi 70 monos.

Perhaps it's time to sell them and move on, I told myself. After 2 unsuccessful listing on Audiogon with one quite frustrating experience, I decided to keep them for a while and attempt to make some mods myself. My "other" set of tube amps are very early pair of Canary 309s with the stock multicaps replaced with Hovland Musicaps. The Canarys sound extremely nice, flavorful, spacious, and detailed, but simply don't have enough power to drive my Eidolons when playing loud symphonic passages or piano like Chopin Scherzi. With the belief that Hovland Musicaps might give the NPMs a fuller texture and musicality I decided to give them a try. My gut tells me that by slightly increasing the value I might get a fuller sound, I opted for 0.15uF replacing the stock 0.1uF. I'm very glad I took the leap. Violins sounded fleshier and piano music sounded more coherent during transients. I like the harmonics of the Hovlands better than the Dynamicaps. Fortunately it did not come at the expense of the "air" department.

I'm now on a roll to try to further improve the sonic capabilities. After reading Mike Elliott's pages on in which he mentions some details of the different stages of modifications (it was very kind and generous of him), I decided to swap out the probably-aged power supply filter caps and the bridge rectifier supplying power to the output stage. I purchased the service manual from Mike just to make sure I can identify the parts correctly before I operate on the amps.

It was about $550 in parts, some time figuring out how best to clamp down the new capacitors (they don't have screw on connectors like the old ones) and many trips to the electronics surplus store. With the help of my friend we got everything swapped in and it was time to see if tweaking the power supply makes a difference.

After about 30 minutes of warm up time I decided to one by one play the "reference" CDs I am most familiar with, starting with the ones mentioned earlier. I cannot believe what a difference this "DIY-partial-premium-upgrade" has made to the amps. I guess I don't have to write anything myself to describe the improvement. Everything that Mike mentioned in the Premium Upgrade paragraph of is true. The amps are now in a totally different class than before. They sound warm and sweet, preserve unbelievable low level inner detail, with lots of dynamic headroom and tonal stability to spare. They play loud and complex passages with no hint of coolness, hardening, or "nervousness". Bass is much faster, deeper, and significantly more articulate. The slight glare of the clarinet when playing certain passages in I'm confessin/Jazz at the Pawnshop/Proprius is eliminated. Piano music has never been a problem but I am talking about playing violin concertos right (I have never gotten a solid state amp playing violin right) with the dramatic emotion conveyed only by the Canary 309s, with bass oomph that gets close to the Pass X350.5.

I guess I should have gotten the premium upgrade in the first place. But it's more fun going through the process."

(The current system they are in now:
Sonic Frontiers SFCD1 with I2Se mod
Sonic Frontiers Processor 3
Audio Research Ref 1 with Auricaps and Tesla NOS tubes
Reference power amp: VAC Phi70 Monos
Avalon Eidolon)

T-Amps- A Preliminary Assessment

A veteran reader and contributor has sent me two letters concerning these potentially revolutionary components. Here they are, with some minor editing and my bold:

Letter One:

"The Sonic Impact T-Amp II (as at ref) arrived yesterday as did some new albums. I put the T-Amp II into my system, replacing my Wright Sound 2A3 SETs, to start breaking it in get an initial impression of it. I left the Wright Sound line stage in place.

My initial impression was an unmistakable presence of 'solid state' background, or that which causes listening fatigue. And that the sound wasn't bad at all for such a diminutive little amp. By the 3rd new album - Brubeck's Time Out - I really sat up and took notice. It had a better sound-floor than the 2A3 SETs, deeper sound stage and was all around more articulate. High frequency extension was noteworthy. It was good enough to have me pulling out several albums to hear what they would sound like. The solid state background was there, but the T-Amp II did so well that it wasn't too hard to live with for an evening. Because my Audio Nirvana Super 8 full range drivers are still in the small open baffles I built, I can't say much about the bass other than what was there - upper bass, mainly - was quite good. Controlling the volume from the T-Amp II appeared to be at least as good as from the Wright line stage, and possibly a bit better.

My sense is that the 6moons review is essentially correct. I'm going to leave it running for a week to break it in more and fully charge the capacitors (as per your advice for solid state) before thinking about a proper A/B, but I already suspect that this amp may re-define value in audio. Having started with your Entry-Level Adcom 535 II, slightly modded with a better (sonically) ceramic fuse, I can say that I would probably use the 535 for a boat anchor after hearing the T-Amp II. I will have spent about $500 for the T-amp and my AN Super 8 speakers (98 db/w/m in cabinet, in room) when all is said and done. It is an obvious approach to building an initial system.

Since the T-Amp II is solid state, it is supposed to like 4 ohm loads better than the AN Super 8's 8 ohm load. The AN speakers have dual driver variants. If the 2 drivers are in series, I believe there is a 3 db/w/m gain for the driver array but the impedance halves. Thus, such a speaker would be 4 ohm / ~ 101/db/w/m, arguably an excellent match to the T-Amp II. Come to think of it, used Klipschorns might not sound too bad either, for all their faults.

I would also advise that serious audiophiles with highly revealing systems purchase and audition this amp. At less than the volume of a loaf of break (and this in the box!), its storage requirement is minimal. It would serve as an interesting reference in cost-benefit, and at about a third the price of a good pair of 300Bs ($140), it's a no brainer for a cheap, fun backup for when the primary amp goes to the shop or is put up for sale to finance a new purchase. Those few I've seen for sale used go for $110 - $120, so the net cost to audition this amp is about $20 plus shipping and taxes. It doesn't get any cheaper than this.

Unless my A/B yields some surprises, my plan is to sell the Wright line stage and amps, and buy a Promitheus TVC line stage (which will net me $700 US with the best Promitheus variant, their 'dual box'). Then I'll do the Sony Playstation 1 - Alchemist Nexus A/B to see if the Alchemist stays (if it doesn't, my net goes to approx $1,100). I can then re-invest in my system elsewhere."

Letter Two:

"I have learned more with regard to my Sonic Impact T-Amp (the 'deluxe' version). It appears that a second manufacturer is using the same underlying tri-path chipset to make a similar amp: the Trends TA-10 Class-T Amp (again an award from 6moons). Also see
The manufacturer's site is at
Supposedly the Trends folks had a good look at the Sonic Impact offerings before designing their amp, so the TA-10 may be better.

With the only disadvantage over my previous 2A3 SET being the unavoidable 'solid state fatigue' issue - that difficult to characterize aspect that one only understands after listening to tube electronics - the T-Amp does just about everything better, and not subtly so. With low-cost, high-efficiency drivers and speakers now an option (e.g. Audio Nirvana), the tri-path based amplifiers not only have the potential to revolutionize the Entry-Level amplifiers but arguably Class C as well.

This may seem ludicrous, but two of these amps have won 6moons awards and been deemed worthy/intriguing enough to be listened to with Avantgardes, in order to have sufficient resolution to hear their ultimate performance. This to me says they're very good, which is consistent with what I hear. If they're this good and cost in the vicinity of $125, one can't help wonder if they aren't a potential Class C candidate too."

Personal Notes- I haven't heard any of these amplifiers yet. This entire "T-Amp Mania" almost sounds "too good to be true", but you must keep an open mind, because it's always possible for a particular technological breakthrough to benefit even the pickiest of purists, along with everyone else. Any further observations and insights I receive on this subject, from this reader, will be posted here.

SET Amplifiers and Electrostatic Speakers

A veteran reader, from Italy, has conducted a unique and pretty thorough experiment with various 300B SET amplifiers and electrostatic speakers. Here's the relevant part of his letter, with some editing and my bold:

"I made some further comparison trying to match a few SET amplifiers with electrostatic speakers; first of all the ACOUSTAT Spectra1 (which I sold recently due to space reasons), then Audiostatic ES400 (late '80s); and my old Beveridge Model 3.

I had in my room the following amps:
MASTERSOUND 300B S.E. (integrated amp)
AUDIO NOTE Conquest (parallel 300B)
YAQUIN ms300b (Integrated amp)
a diy amp home made by one of my friend with a parallel 300b schematic circuit (approx. 13 w per channel).

Actually, I was very frustrated by the result, with the three pairs of speakers, the sound exhibited by all amps was evidently far from excellent. Generally speaking, the sound was poor and not "alive", and with a pronunciated roll-off on extreme frequencies (bass and highs). Sound in the bass region was very muddy, not controlled and not extended in the very low frequencies.

The phenomenon appearently was similar with all the amps. Evidently, they were close to the same configuration of tube and circuit. It was not only a problem of volume pressure, but especially lacking of micro and macro contrast with all kind of music. All the speakers tried are between 84 and 87 db efficiency, but I suppose you're right (as you affirm in your paragraph April 2007-My recent amplifier history), that the problem is the low impedance.

All the speakers in my possession have a minimum of 2,3/3,5 ohms in the upper high frequencies, but also, in the crucial midrange area, things are not much better, with an impedance and phase shift diagram that seems to switch back from low to high, and then back to low again..."

Personal Notes- On paper, an electrostatic/SET match, that actually worked, should result in unprecedented musical reproduction, since their strengths are similar (especially in the midrange). However, this reader's pathetic experiences are similar to that of my associates and I, though we only performed one or two experiments, and none with a "parallel" 300B amp. Considering the typical electrostatic's low sensitivity, and its low and varying impedances, these highly discouraging results are not surprising. Still...

I wonder how a more powerful SET amplifier (845, 211 etc.) would work? I'm also curious how the new Coincident Frankenstein 300B will work with something like the original (or the later versions of the) Quad Electrostatic.

An Interesting SS Amplifier

A veteran reader has sent information about a new transistor power amplifier that focuses on solving what has been the main sonic problem inherent with those designs. Very little editing and my bold:

"I (would like to) make short mention of the Aspen LifeForce amplifier, as it's my amplifier of choice at the moment. This amplifier came out about a year ago from Hugh Dean, aka AKSA, and I believe I got the first pair of amplifier modules Hugh put out on the market. This amplifier differs from every other solid state class AB amplifier in that it has the designed capability to amplify in the low voltage crossover regions between + voltage and - voltage. This is where all the low level detail and spacial information is at, and the inability of class AB solid state amplifiers to amplify in this low voltage region has always been the achilles heel of those designs. But with the LF amplifiers you get the low level detail and spacial sound of a fine tube amp, and the excellent bass and high frequency response capabilities of the best solid state designs. There just aren't many of these amplifiers around, anywhere, at the moment. Hugh will exhibit at October's RMAF in Denver, and hopefully will get some notice and attention there, as I think they are deserving of such."

Personal Note- Time will tell whether the LifeForce amplifier really does equal "a fine tube amp" at its best. Hopefully, another reader can provide further first-hand observations of this amplifier, for better or worse.


This is another letter from a reader who has been knocked out by the performance of the Don Allen amplifiers. There are far too many experienced audiophiles who have been seriously impressed with these components for it to be a simple "fluke". Allen's design strategy, as described below, is also very appealing to me. No editing, but my bold as usual:

"As I was reading the information on your site I noticed that you mentioned Don Allen's amps. I have been an audiophile for over 40 years and have heard a wide range of equipment. At various times I have had systems costing over $100,000. About a year ago I stumbled on Don Allen when I was looking for someone to repair one of my amps. It was the best discovery I ever made.

I currently own 300b, 45, 10/10y/801A monoblocks built by him. I also have his preamps, modified CD players, and phono preamps. In all cases they surpass the previous equipment that I have owned or tried. For example when I first met Don I was using a Conrad Johnson Art II preamp in one system and a Wavelength preamp in another. Don's preamp, that cost about $700, was so superior to the other preamps I was amazed. I really could not believe it. It just didn't make sense to me that something that inexpensive could sound so good. I acually had several dealer out who confirmed my observations.

After talking at length with Don I feel his equipment sounds as good as it does for several reasons:
- He uses simple circuits. He believes less is best. The more that is added the more you change the music.
- Don is able to visualize the various fields that each component gives off and he minimizes interference. He literally designs each piece in his head and than builds from the image.
- He uses the components and designs that he has discovered over years of tinkering to get the best sound. Often this means goes against what is held as the truth in the audiophile community.
- If he feels something sounds great and others don't he is willing to find out why there is a difference of opinion. He does not blindly defend his beliefs.

There may be better equipment out there, I just have not found it. Also at his prices I can have several different amps and listen to different sounds as my mood changes. I should point out that I mainly like Jazz, classical, and vocals. Other equipment may be better for other types of music. For speakers I am currently using Von Schweikert DB99's and custom speakers design by Don and built by a local speaker manufacturer." 9/07

Don Allen - Contact Information

I'm receiving a steady stream of requests about how to contact Don Allen of Phoenix, Arizona. A growing number of audiophiles swear by his custom built tube amplifiers, plus his tube electronic repair skills. As far as I know, this is his current e-mail address:

Also, Don's one phone number is also his private phone number, so I would think twice before calling him. This is why I will not post it.


Here's a somewhat lengthy letter from a veteran reader. I found it interesting, especially since it is also relevant to owners of Vandersteen 2Ci speaker. There's some minor editing:

"I was reviewing the Reference amplifier files and noticed you had included the Counterpoint amps. My brother had the SA-100 and drove the exact same Vandersteen 2Ci as I did. He was fortunate in that he sold it before anything happened. Michael Eliott on his website states that the output transistors are no longer available and that a complete changeout and upgrade to new transistors and drive circuitry will be necessary in the event of output failure. Also, there is another component that failed quite often after long use and will need to be upgraded to protect the amp. Readers should know that the SA-100 will need to be upgraded to be reliable, and as you stated, Elliott isn't cheap when it comes to upgrades.

The quality of the SA-100 circuit boards and components was no better than my much less expensive B&K ST-202+ and the B&K had much higher output power and three pairs of output transistors per channel vs. the two pairs on the SA-100. That gives the ST-202+ much more current drive capability, never mind the extra power it provides. Also, having used the ST-202+ heavily for 14 years without incident, I can state it's quite reliable. Do not confuse it with the more common ST-202 that has a much smaller power transformer and only two pairs of outputs like the SA-100. On Vandersteen 2Ci speakers, the B&K ST-202+ was clearly better if you wanted to really raise the roof when playing music. Even my dealer stated it took at least 100 watts of high current power to wake up the 2Ci speakers, and he also sold Counterpoint. The 202+ has a huge toroidal power transformer rated at 600VA continuous, which will provide 1500 to 1800 VA under short duration surges. That will easily supply the 300W per channel that the ST-202+ is rated at. The ST-202+ is worth looking for, but you will rarely find them for sale. Mine is not for sale, at least not anywhere near what a ST-202 goes for. As long as I have the 2Ci speakers, I will value the ST-202+ above a counterpoint SA-100, and it has no issues requiring upgrades/reliability. The 2Ci drops to 5 ohms where a lot of heavy bass is produced and an amp rated at least 200W at 4 ohms is best, with very high current delivery and very low output impedance.

My C-J MF-2250 is rated 225W at 4 ohms and also has a monster transformer similar in power to the ST-202+. The SA-100 had an output impedance of around 1 ohm, which is far higher than my C-J MF-2250. The SA-100 was not a suitable amp for low impedance power huingry speakers with my taste for tight bass. The SA-100 has nowhere near the continuous current capability of either amp, and a much higher output impedance around 1 ohm, same as a tube amp. Neglecting to put a very high current amp (the current rating will be more important than the power rating) on the 2Ci is one reason some people consider it laid back and polite. The mosfet outputs of the SA-100 will heat up and restrict current delivery when driving the 2Ci or any similar speaker very hard, while the bipolar outputs of the MF-2250 will actually decrease output impedance when heated and driving a hard load.

I live in a house now and can really blast my music. Apartment dwellers might be happy with an SA-100, provided it doesn't break. For Elliott's upgrade cost, I could probably buy an excellent ST-202+ and stick change in my pocket and have a better amp for raising the roof with the 2Ci. As you stated, a properly configured system should not need an active line stage. The partnering B & K Pro-10MC is such a preamp. Just punch a button and the active line stage is bypassed. Moving coil phono preamp is included (hence the MC designation), and it's a good MC preamp. An external power transformer is standard, almost unheard of at its price point. The trick is to replace the 100K volume pot with something like a 10K or 20K TKD conductive plastic pot which I picked up for $65 at Welborne Labs. The only negative with the Pro-10MC after volume pot replacement is the ribbon cable that connects the output RCA jacks to the circuitry. If you are recording or running another source while listening to another source, you can heard crosstalk during quiet passages and also on your recorded material. Install shielded or twisted pair wiring, and that problem is also solved. I had a Hafler preamp, and it's nowhere in the league of the Pro-10MC.

I know of at least 4 versions of the Pro-10MC. Mine is the 2nd version with rack handles and more controls than the original version which was very minimalist in design. It has separate listen and record selector switches on the far left panel. The latest 2 versions had no rack handles. Many people consider the early versions the best, but I never heard them. Audio magazine tested my version in 1992, and gave it a very high rating saying it gave thrilling sound quality far exceeding its price. Stereophile rated it class C, and that's probably conservative as it probably knocked on lower class B territory and threatened sales of their more expensive advertisers. Off the record, a past Stereophile reviewer commented that the Pro-10MC was a very good preamp. He has enough money that he didn't need his job at Stereophile. Change the pot and cheap ribbon connector, and it would be Class B for its day. Nobody ever complained about the Pro-10MC in my setup. My homebuilt tubed line stage preamp sounded no better than the line stage in the Pro-10MC.

Pro-10MC's have gotten much harder to find lately, as I would have suspected anyway, as there isn't a better solid state preamp with MC phono stage for the price that I know of. You could just buy it for the decent MC phono stage (60 dB gain) and keep the rest for a backup or stereo home theater preamp. My local Dallas dealer once had one in excellent condition for $275, but they usually sold for around $350 used. My biggest gripe is that it did not have remote control, thus my move up to the remote controlled C-J PV-14L which improves on the sonics only slightly and has no phono stage, so I bought the matching C-J EV-1.

Yes, it took $3,500 worth of C-J preamp and phono stage to get noticeable improvement. Neither has an outboard transformer. Both take up much more rack space. I gave $580 new in 1991 for the Pro-10MC, which makes it a giant killer. It never had a breakdown of any sort, ran it almost every day for 14 years, and it sounds as good as new. The move up from ST-202+ to MF-2250 was a lot more noticeable than from the Pro10-MC to PV-14L/EV-1. That shows how good the Pro10-MC is, as the PV-14L and EV-1 have gotten very good reviews relative to their price point. The Adcom and Hafler gear I have heard simply does not compare to the B & K gear of that era. B & K had that fluid quality with very low listening fatigue, similar to C-J, with rich timbre similar to good tube gear. Never once was I aggravated with hashy, dry, grainy, etched solid state sound that commonly existed at that price point. The Pro-10MC should be at the top of the list of entry level solid state preamps. When I search eBay these days, rarely do I see them for sale anymore. Most must have finally found appreciative homes, I suspect."

Personal Notes- I had extensive experience with the early B & K amplifiers from the 1980s. The owner/designer visited my retail store on several occassions, though I'm no longer certain whether I was ever an "official" dealer. Later, I had a number of their amplifiers come in as trade-ins. I do remember that the amplifiers were noticeably more natural than their competitors, and my customers were very happy with them. I had less success with their Pro-10MC preamplifier (version unknown). I had one come in during the middle/late 1990s, and while it performed well, it had chronic reliability problems.

The same reader added later sent me this addendum and correction to his above letter:

"I incorrectly stated the volume pot on the Pro-10MC was 50K. That's the measured input impedance at full volume with the 100K volume pot in parallel with the 100K balance pot. The volume pot is 100K, and after experimenting with lower impedance pots, I am staying with the 100K pot since I like the preamp better in the active mode. My CD player sounded better into a high impedance load. I would NOT suggest changing out the Pro-10MC pot unless an owner knows what he is doing. It is soldered into the circuit board, as is the balance pot. If you change volume pot to lower value, you will also want to go down to a lower value balance pot IF you intend on using it in the passive mode with balance control. The balance pot adds output impedance when off the centered position. But again, I heard no benefit of running in passive mode once the system is sorted out. See below.

I forgot to state one of the BEST uses of the Pro-10MC. I still use it as my headphone amplifier, and have for years. I have the $70 Grado SR-60 headphones, and once had $200 SR 200 headphones, but I prefer my 600 ohm Sennheiser HD 450-13II/600R headphones. These are pro style headphones for line level 600 ohm sources that are readily available from broadcast and recording studio suppliers. Usually not seen in audiophile catalogs. The Pro-10MC has headphone output, BUT it's directly off the line outputs which are switched to the headphone jack. There is no additional internal headphone amp to color the sound. The line output is 200 ohms, so some low impedance headphones might not be a good idea. With 600 ohm pro headphones, it has a really good sound. Your headphone jack must have sufficient VOLTAGE SWING to handle 600 ohm pro headphones. You will get about 20 volts from a CD player with the Pro-10MC. Many headphone outputs are lower voltage with higher current capability for low impedance headphones like 40 ohm Grado. The price of a good used Pro-10MC is also no more than a good headphone amp, so the preamp is well worth the money as a phono amp and headphone amp, even if you drive nothing else. It's probably better than the headphone output on cheap CD players. With many CD players and preamps not including a headphone output, the Pro-10MC stands out even more in value. I tie the headphone cable to the rack handle to keep strain off the headphone jack.

In the active mode, I suggest ferrite coaxial cable clamp-on RF noise suppressors on the CD player interconnects. The Pro-10MC is very wide bandwidth. Much more than the B&K amps, and more transparent. I put a clamp-on suppressor near each RCA plug, and at $5 per clamp at Radio Shack that comes to $20 for a cable set. You at least need a pair of RF suppressors. If a person does not believe a CD player puts out lots of RF hash, turn your CD player on and of while listening to an FM tuner connected to your preamp. Not all the hash comes through the interconnects, but a lot does. I isolate the CD player power cord from my other components in my power filter bank. It can make a cheap CD player a lot easier to listen to. Other than that, leave a cheap CD player powered up all the time and it may smooth out. And it may not.......dump it and try again. My Pro-10MC came with a test sheet showing it is flat as a board to 100kHz, and another sheet for the phono preamp test curve proving the + or - .25dB RIAA response. B&K got the transformer and its associated noise out of the chassis, and you need to take steps to see the noise stays out. I also suggest shielded interconnects with the shield connected only on one end, and connect all shields to the preamp end. I have also heard that Spectral amps are also persnickety with RF noise, and it's probably a result of the very wide bandwidth design. My B&K amp came with a non-polarized plug, so if you use a B&K amp try the plug both ways in your power outlet.

A truly cheap CD player that sounds good and is reliable is an old Technics SL-P230. Should be able to get one off eBay for under $50 delivered in very good condition. One of the first cheap CD players with dual DAC's and 4X oversampling filter. Compares well to a Rotel RCD855, no kidding........much cheaper and better looking too. Very minimalist interior circuit design, as in so simple I don't know how the thing even works as I can't find where necessary chips are located. They must be incorporated in the drive mechanism or something. Most really cheap CD players bother me, but I can hardly tell this one from a Rotel RCD855 that was so highly rated in the early 90s. I keep one in my office rig, feeding the Pro-10MC. I bought this one in 1989 for a bit over $200, and not a single problem since. I have fixed the RCD855 two times already. The remote is also nicer on the SL-P230. Technics gear is incredibly reliable, making it good for cash strapped music lovers." 9/07

Two Canary Amplifiers - The CA-339 and The Reference One - A Comparison

A reader, who only recently became aware of this website, has gracefully responded to a specific question I asked after reading his first e-mail to me: "How do the Canary Reference One amps compare to the CA-339 amps?". Below is his response. There's only minor editing and the bold is mine.

"I have been involved with audio for about 40 years, having owned a real variety of equipment and speakers. My first pair of speakers were Altec Valencias and my second pair were Klipsch Cornerhorns with a La Scala center speaker, since then there have been several B&W's, JMLab Utopias, Wilsons and so on.

My current system is all Canary tubes; CA-903 four box preamps (separate left and right preamps with separate power supplies), CA-400 (two box phono section with preamp and power supply separate), CD-200 and the Reference One monoblocks. Two months ago I got a new Transrotor turntable and installed a Graham Phantom arm with a Dynavector XV-1s cartridge (and yes, it does sound and track better at your recommended 2.7 grams* then the factories 2.2 grams). The wiring is all Analysis Plus gold interconnects (RCA) and speaker wire with AP power cords, except on the amps; they are Guerrilla's. The speakers are B&W Matrix 800s (93 db). My audio room is 40 feet by 38 feet by 9 feet tall.

The Reference Ones are large; 29" long, 16" wide and 10" tall, and weigh 150 pounds each. Each monoblock has the following tube compliment; eight 300B power tubes, three 6SN7s and one 6SL7. I am using the Western Electric 300B tubes and the 6SN7s and 6SL7s are GE NOS. The monoblocks are sold without the power tubes.

Your comments about the Canary CA-339 prompted me to write and give you my comments on the CA-339 and the Reference Ones. Several months ago, I responded to an ad in Audiogon for a pair of B&W Matrix 800s that were for sale. I was considering using them with my current pair for the rear speakers in a home theater system. The short version is that Terry, the B&W speaker owner, having heard me comment on how fantastic the Canarys sounded on the B&Ws, decided to keep his speakers and bought a pair of Canary CA-339s. He was pleased with them, but did not feel they provided the depth of sound he had heard me describe with the Reference Ones. Terry lives in Chicago and I live a short 328 miles away in the Detroit suburbs, so Terry drove out with his CA-339s to compare them to my Reference Ones on the same B&W speakers.

We hooked up the CA-339s first, to give Terry a baseline, and me as well, since I had never heard a pair before. I was pleased to hear a few 'similarities' between the siblings, but similarity was all that it was. I should make a quick comment here; the CA-339s, like the Reference Ones, are delivered without power tubes, leaving the new owner with the decision as to what to buy. Terry bought Electro Harminex 300B tubes, which were not a good choice. Switching my Western Electrics 300Bs into the CA-339s made a very solid improvement, but candidly nothing like what the Reference Ones could do with the same 300Bs.

Hooking up the Reference Ones and playing the same music drew a huge reaction from Terry. The CA-339s are rated at 50 watts per channel and the Reference Ones are rated at 80 watts per channel. The difference in sound seemed more like 800 then 80. My B&Ws are 12 feet apart and do not see a side wall for a little over 13 feet. Terry's first comment was on the huge holographic soundstage that was providing detail and clarity he had never heard before. He also commented on what he meant by the soundstage being holographic; he was explaining how the speakers, all 6' 2" of them, disappeared, while the sound and source were seamless.

The Reference Ones catch the very essence of a piano note, the upper detail and edge, without going into bright or edgy, which also applies to the female voice or violins. This is one pair of amps that can truly make the claim that they sound like you are there live. I can write word after word, but, candidly, unless they just happen to be the perfect match for the B&W Matrix 800s, they reproduce music like I have never heard before. Terry left that day and sold his CA-339s, and bought the Reference Ones and front end identical to mine. I have had several of the local high end store salesmen over, including the local B&W dealer, who has commented he has never heard anything as clean, detailed and musical as this. Today, I would not buy any of the new B&W speakers as they sound slow, muddy and not too musical.

I should make a comment on the Reference Ones, being tube amps and their bass response; It is huge, fast and extremely well controlled. They humble the Krells. I have been looking for a speaker for several years to replace the B&Ws, and have listened to Avalon Isis, JMLab BE Grand Utopias and several well heeled others. However, I will make a brief comment on a recent (6 months ago) listen to a pair of Wilson Maxx 2s. I listened to them with the ultimate full Krell front end, and found them lacking in detail, warmth and any form of making the music 'musical' or exciting. After only ten minutes of listening, I thanked the dealer and, when I was leaving, he asked me what I thought. I told him that I had fully expected the Maxx 2s to have a lot more depth of presentation then what I heard. After a few minutes of discussion and learning that I had a tube system, he suggested that I try the Maxx 2s on the Canarys. In short, I agreed to bring my whole Canary front end down one night to see what the Canarys would do, or not do, for the Maxx 2s.

Five of us listened to the Maxx 2s on the Krell system for about ten minutes, then switched over to the Canarys. The difference was unreal; a really wonderful and musical presentation was coming from the Maxx 2s. After about two hours of listening, it was obvious that the Canarys, now fully warmed up, were leagues above the Krells in any part of the musical presentation you cared to listen to. My immediate reaction when I got home that night was to hook up my system, and compare how the B&Ws sounded against the Maxx 2s. To my and several of my attending audio friends, we were all in agreement that the 800s were every bit as good and maybe slightly better in a few areas then the Maxx 2s.

I have not used all of the usual audio hype words that the magazines are full in trying to describe why the product they are reviewing is the latest and greatest. I can tell you that nothing, including my previous VTLs, Jadis and Convergent Audio Technologies tubes has ever presented the music in the same concise, clear and seamless sound that the Reference Ones do. Tubes or not, the Reference Ones will put out bass that is as controlled, fast and in your face as any transistor amp I have ever heard and will do it with a warmth and musicality of the mid-range and treble that a transistor will not match. Canary has recently upgraded a few circuits and added larger transformers that have enhanced their sound even more, which is in the current amps I have now.

I have admittedly not used all of the buzz words because I can just state that you will not find anything better in an amplifier then this one. I am sure there are several speakers out there would not be an ideal match for the Reference Ones, but for the other 95% of the speakers out there, you need to hear these amps. I believe that only 26 pairs of these amps have been made, most going to Europe or Asia, but anyone interested in hearing these on my old, but clearly still fantastic B&Ws, they are welcome anytime they make it to Detroit.

...If the CA-339s are a 88% on a scale of 100 being perfect, then the Reference Ones are clearly a 94% to 95%, and I would like to hear anything above that myself." (12/07)

Personal Notes- I'm not surprised by any of the comparative results and/or the observations of this (highly experienced) reader and his fellow audiophiles, especially when they directly compared the Canary to the Krell electronics. In fact, Krell has lost every single "shootout" I can remember conducting with them. However...

*I am surprised that the Dynavector XV-1s cartridge requires 2.7 grams VTF on the Graham Phantom tonearm. In the past, I always assumed (and posted) that only the VPI Memorial tonearms required this heavier force for optimization. Now I'm proved wrong, so I guess these two basic designs share some particular similarity.

ASL Hurricane MKII Amplifier (A Technical Problem and Solution)

I received this letter from veteran modifier and long-time contributor, Bill Baker of Response Audio, who has more expertise with the Hurricane(s) than anyone I know. Here's some potentially useful information about the new MKII from Bill (minor editing):

"I do have some information on the initial earlier batch of MKII units (early 2007) that your readers may be interested in. With the new vertical chassis, the MK II obviously uses two sections now. The lower base contains the complete power supply and bias circuits while the upper section contains the main circuitry. For those who may be experiencing problems with severe bias drift with the early MKII, there are a series of green connectors (male/female) that provide the "link" for all the wiring between the upper and lower sections. I have confirmed that there was a potential problem with these connectors. The very first pair of MKII Hurricanes I modified in January 2007 developed a severe bias drift problem within a few months. The customer just got around to sending them back to me to look at. Upon opening them up, I found one of these connectors was burned out. I have not yet replaced these connectors, but I am confident that this will resolve the issue." (1/08)

Esoteric Audio Research (EAR) 509 Amplifier

A long-time reader sent me his reflections on the EAR 509 amplifier, which he has owned for more than 20 years. There's more than the normal editing since English is not the reader's first language, plus my bold:

"...I read your recent added comments on the EAR 509 amps... I have other power amps, but I own also a pair of Tim de Paravicini's design since 1986. I acquired considerable experiences in those many years, and I can provide you with further impressions.

(They are) quite reliable (only one failure for each amp in 20 years), and cheap to retube. You gave evidence of their exceptional qualities in dynamics. I agree with you; the same when you describe their excellent bass (less extended in the very low region and less punch in respect of best transistor design, but still better than a large majority of tube amps). They also have great detail and a bright balance. I'm not so persuaded of that unnatural quality you mention, but maybe it's a main character of the unusual pentode power tubes employed (PL509/519).

The other face of the coin? Their sound qualities varies more than usual both in respect of the preamp used and also regarding the speakers. We must consider the input impedance of 25k ohms, which is a very low and a hostile value for many tube preamps. I made one modification only, in disconnecting the volume pot at the rear, so the new impedance value raise to an easier 100k ohms. You do lose in flexibility, since you can no longer connect directly to the source (cd, tuner), but then it's not an irreversible modification.

My experience is that sonically they are an unusual amp in respect of the speaker. It seems that easier loads, like many dynamic speakers or the old Maggies, are not the best match with EAR monos. They are not exactly "dirty", but I admit that many recent power amps will demonstrate a more purer tonal balance.

On the contrary, they are a great companion with some electrostatic speakers, especially the ones that (in most cases) sound "dead" and have poor dynamic contrasts (not the Audiostatics which are more immediate and more sensitive). With EAR monos, speakers like Stax ELS-F81, Quad 57 or Beveridge 3 exhibit all of their best qualities; better wide than deep soundstage and nice sense of air in the musical performance. Still I always have the sensation of hearing the music in a context similar to a medium size concert hall; IMHO, they are sonically addictive, like some kind of a decay or reverberation of the sound.

My above considerations are referring to the original version, and not to the Anniversary Edition recently introduced by EAR-Yoshino with balanced inputs. The former is still competitive in the used market, and places the amp in a league with many many great competitors."

Altec 1570B

A veteran reader sent me his latest observations. Here it is, with some minor editing and my bold:

"I finally received in May my new Altec/Tutay 1570Bs! They are really astonishing and work very well with the Quads 989s. I only waited 9 months...:) Interestingly, I didn't find all that much difference when swapping the 811As for 572Bs. What made more difference was to exchange the 12AT7s provided by Tom with Telefunkens; the Telefunkens brought more clarity, in particular in the mid-range and more transparency overall. The synergy with the Bent Audio passive preamp is wonderful, and I have plenty of gain for all sources.

(Second letter from same reader shortly thereafter...)

"Just a quick note to rectify my initial comment on swapping 811As with 572Bs on the Altec/Tutay amps. I went back to the 811As to compare, and indeed the 572Bs add quite a bit of punch to the sound, without taking anything away in clarity, transparency etc. I think I hadn't fully burnt-in the 572Bs when I made the first assessment. So they're staying in." (7/08)


Even though they are located in Ontario, Canada, I've never heard of this company, and they make a good variety of interesting tube amplifiers. One reader is very impressed with them. His letter below has some editing and both his and my bold. A link to McAlister Audio is below and in the Links File.

"Just came from my friendís house with the McAlister OTL 195 hooked to his Acoustat 3. This is the best reproduced sound I have ever heard from any system at any price, bar none. So what is so good about it?

Letís start with the obvious Ė the Acoustat 3 is a damn hard speaker to drive. I cannot emphasize it more and you probably are well aware of this fact so I will not dwell on that too much. Suffice to say it is extremely difficult to assume this speakerís potential and most owners drive them with a dry-as-a-toast and hard-as-a-rock high power solid state amp. This is the best way to give up on these speakers as this way they lack everything that is important (to me) in music Ė the emotion, the spatial information, the micro-dynamics, etc, etc. One ex owner even told me: they create a sound stage that crushes to the floor two meters from the speakersÖoh well.

My friend used to drive them with McAlister MB-130, 130 w/channel push-pull, TV sweep (27GB5) tube design. They worked well, but the amp was straining, mid range was a bit too forward and aggressive, compression would set-in at times and harshness and aggressiveness would kick-in. It felt like the amp is trying too hard. Not with the OTLís.

The word 'Purity' comes to mind. What does sound 'purity' means? Effortless, cleanliness, very detailed presentation with texture and micro-dynamics but most of all, an uncanny presentation of contrasts between music and silence. To use your terms, I would have to say: an ultra low sound floor. It almost feels like the sound comes from outer space and it is immediate and intimate as they get (given the recording calls for it).

My 300B/805 A2 SET driving my Sonus Faber Grand Piano sounds smeared in comparison (and it is not smeared until you compare to these OTLís). Just to show there is always higher mountain in this hobby. Then there is better bass control and bass cleanliness than with the MB-130 and unbelievable smoothness (it is more unbelievable given the very detailed presentation Ė very unusual as ultra detailed sound usually comes with a price like brightness, sibilance, harshness or raspiness. Not here. Eva Cassidy, that tends to 'shout at you' at times, sounds detailed, extended top to bottom and smooth all at the same time).

I am speechless, really. Sometimes descriptions just do a disservice to a listening experience because when it sounds so right you do not even feel that you want to describe why. You just want to listen (and than sell your gear, give up this hobby and get a boom-box insteadÖ). This is one of the best kept secrets that reminds me of the Buddhism phrases about whether a tree that falls in the middle of forest when nobody is there to hear it actually makes a sound or not..." (8/09)


A reader, who owns the Altecs, forwarded some initial observations concerning different output tubes with this amplifier. This was a year ago or so. Since then, he's had a change of mind based on his more recent experiences. Here they are with minor editing, but with my bold:

"First, my last note about the 572Bs: those tubes, bought on eBay from a Chinese source, turned out to be defective. The first batch of 4 I bought from them lasted about a month before they went bad. I got another quads, and those didn't last a week. When I complained to the seller, I was just told that they never have any problems with them, they sell all over the world etc etc. For them, the culprit was the amp construction. What a joke! So it's back with the 811As, which sound very good anyway.

In the meantime, Tom (Tutay) gave me instructions to change the wiring of these output tubes, so that I could use American 811As, such as the RCAs, which require a slightly bigger cap (the connector on top of the tube). He sent me new connectors, and all I had to do was to mount new jacks on the chassis so that I could easily swap connectors and caps in order to use either Chinese or American 811As." (10/09)

Sonic Frontiers Power Amplifier Modifications

I have no memory of ever auditioning the Sonic Frontiers power amplifiers, but some of my associates heard them when they came out (and since then), and they all told me the amps were mediocre, at best. Fortunately, a helpful reader may have found some potential in them. Here is his letter (with some minor editing and my bold):

"I briefly owned SF Power 3s in the late 90s, attempting to get some bass from my then Avalon Ascents, using brute-force. The Power 3s were the grainiest and most uninvolving power amps I have had, second only to Audio Research VT200. No depth, no inner detail, no coherence.

Fast forward 10+ years, and I recently had the opportunity to 'upgrade' a friend's Power 2. Initially I tried to discourage him from throwing good money at bad, but the owner insisted.

The amp simply didn't sound right in (as expected) driving my Eidolons. First it was a bold mod to triode mode, which got rid of the annoying ultralinear incoherence (ultralinear to my ears is anything but linear). Replacing the flat-sounding Multi-caps coupling caps with V-Caps in the gain stage coupling, and Mundorf M-Silver gold oil in the driver stage, completely turned the amp into a different animal altogether (big money, but the result is worth it).

The amp is now extremely transparent, yet warm and musical, and still has more than enough juice to play Mahler. With the exception of the need for 'sacrificial resistors', in case of a runaway power tube, the amp is very well built and has a lot of the convenience features one would want from any modern amp today.

I guess what happened was SF was overly obsessed with 'specmanship', to hang with the measurements of Audio Research in the power and distortion numbers dept, that they assembled a pc of monstrosity from extremely high quality power supplies and chassis tooling." (10/10)

The Original Sunfire Amplifiers

A reader, with a considerable amount of experience within the audio industry, sent me this letter, which I felt should be shared, since I was unaware myself of the claims within. Very little editing and my bold:

"I spent many years in the industry as a rep and an audiophile..., but that's not the reason for this letter.

Regarding the Apogees and your caveat that among the high powered amplifiers required to power them, the Levinson ML-2 was recommended. I wanted to share an anecdote you might appreciate.

I had a dealer...who was both a Levinson dealer and an Apogee dealer. I was the Sunfire amplifier rep (also Quad, KEF, Dynavector, Grado, and more) and arranged for Bob Carver to meet with the dealer. The agreement was that Bob himself would show them his new amplifier. Based on their experience with Carver amplifiers, I think they were skeptical at best about Sunfire's potential. Bob Carver's celebrity more than anything else was the impetus for the meeting. Bob used to get irritated when I would complain the Carver amplifiers (not to be confused with the Sunfire) sounded good into high impedance speakers, unfortunately there weren't many on the market!

The meeting was held in the morning prior to the store opening. We were ushered into the 'high end' room, with the Apogees being driven by Mark Levinson mono blocks. I honestly have to admit, I don't recall the model. Bob suggested we unhook those and hook up his 300 watt x 2 amplifier. The look on the faces of the salesmen was basically, 'Bob, you poor uninformed soul. You made cute little cube amps, and Phase Linear was interesting, and we're glad to have met you, but we wish we didn't have to watch you embarrass yourself with your amplifier running Apogees. Let us explain to you how impedance works and how the Levinsons trounce anything you've ever dreamt of building.' I know, I'm taking a lot of liberty, but those sales guys' condescension and underestimation of Bob's talents I have to admit at that moment were probably shared by me!

First, an aside. If you don't know how the Sunfire amplifier works, it is basically load invariant. The tracking down converter, which Bob patented, would basically create a low impedance environment for the output transistors, allowing each output transistor to put out its' maximum rated current. In a typical class AB amplifier, or even class A amplifiers, the lower the speaker impedance, the higher voltage environment for the transistor, the less current the output transistor can produce. In fact they can only put out a small fraction as the load drops to below 4 Ohms or especially in the case of a Scintilla, to below 1 Ohm.

The tracking down converter in the Sunfire allowed the output transistors to live in a 6 volt world, continually adjusting to make sure that 6 volt above operating voltage never varied. In any other solid state amplifier, a demand for high current from the load, .9 Ohms in the case of the Scintilla, the voltage would far exceed that, and an output transistor which is rated 20 amps would put out only a fraction of that with that load.

Krell, and the other boat anchor amplifiers, 'solved' this by using a massive number of output devices, insuring that regardless of the current demands, there were enough outputs devices to put out the current demanded by the load. It's also my opinion why they sounded so bad. I have never heard a Krell amp that didn't sound sterile and cold and could never understand the positive reviews. Well, I sort of did...

The Sunfire had very few output devices, especially for an amplifier capable of 300 x 2 @ 8 Ohms, 600 x 2 @ 4 Ohms, 1,200 x 2 @ 2 Ohms, and 2,400 x 2 @ 1 Ohm. The tracking down converter was the secret and the amplifier literally didn't 'care' what the load was. The tracking down converter made that happen. An elegant and simple device. The amplifier never even got warm running the Apogees LOUD!

Well, the look on the faces of the sales guys changed from smug condescension to shock, then disbelief, then smiles of small boys when they've hit their first home run. I kid you not. They would look at the speakers, look at the amp, look at Bob, look at me, look at each other. Finally, someone said, 'hey, I didn't know these (Apogees) could do bass!' and laughed. Then they turned it down and said, 'Ok, how are you doing this?' Bob tried to explain, and I believe there is a white paper* on the Sunfire site to this day, but the level of technical knowledge of those audiophile salesmen, then as now, was limited to the wives tales, myths, and legends purported as fact by the high end media, Stereophile and TAS.

The Sunfire is capable of lots more current than the Levinson mono blocks, any of them, into low impedance loads. It's a technical fact. I know you probably have a hard time believing that. AND it did so with many fewer output transistors!

Bob never got respect from Absolute Sound other than Robert E Green, the one reviewer at TAS I respect**. He reviewed the Sunfire and was floored by it. REG, as he's known, has been attacked within the pages of TAS by Jonathan Valin several times for refuting several audiophile myths, ironically myths dearly held by some of the other reviewers. I would consider being attacked by Valin a badge of honor! He, REG, appears to be the only 'courageous', honest, and technically astute among them.

I know this may not fit your paradigm that tubes rule. I agree, they do, though I am always leery of ultra-linear designs with their inherently high levels of odd order harmonics and elimination of even order harmonics, the very harmonics you DO want! Getting more power at the expense of unnatural sound is a poor tradeoff IMO.

The Sunfire was designed to drive any load, do it with very few output transistors, very simple circuitry, and to emulate the sound of tubes. I'll let the shock of what I'm saying sink in. If you can find a Sunfire amplifier, any of the old ones with the big meter in the center on Audiogon, eBay, etc. buy it! You will simply not believe how it transforms any of the Apogees.

We actually did little parlor tricks with the Sunfire. With the protection circuitry disabled, you could weld copper sheet together! It would literally keep going right through a dead short! Bob put a 1/4 Ohm protection circuit in, in his words, to protect himself from lawsuits in the event of a voice coil short circuit. The amp would keep on going as a result of the tracking down converter and cause the voice coil to overheat and possibly catch fire...

If you can find the 300 x 2 amplifier, buy it. Usually ridiculously cheap, $1,000 or less. People simply are not aware of the amp's capabilities. The 600 x 2 Signature amp is also a jewel. Rich, warm, smooth, in every way, even low impedance stability, but especially in sound, superior to anything Krell ever built. I know, not much of a compliment. One of, if not THE best solid state amplifiers I've ever heard. Rita's Hi Fi in Seattle will bring the amp to spec regardless of the condition for less than $500, and I think Bob will sign the amp if you request.

Also, the current*** Sunfire amplifiers are just as capable, though they no longer have the retro cool look. Nor will they command a lot of resale on the high end market, Sunfire never courted that market. But for those who know what the Sunfire is, and what it is almost uniquely capable of, it gives you absolute freedom to choose whatever speaker you like, and do it with the fewest output transistors of any comparably powered amplifier." (09/12)


*The white paper does exist, and can be forwarded by reader request.

**"I should add to my previous comments that Steve Stone and Robert Harley appear to be technically astute at TAS. Anthony Cordesman is another and there may be others of which I'm not aware."

***"I'm not sure if the current models will go all the way down to 1 Ohm effortlessly, as did the original models. I know they will double their power all the way down to 2 Ohms, though they no longer publish a 1 Ohm specification."

Personal Notes- I always avoid solid-state amplifiers, based on decades of (disappointing) experiences, including recently, but I must admit that I am now intrigued with the Sunfire amplifiers. I would need two in my system, since I am biamping, which is still not a large investment considering what I have already spent. If I get an opportunity to hear them, I will take it, and report back. Any reader who has experience with these amplifiers is encouraged to share their experience, which I will post.

Also, Stereophile may have a valid excuse for missing the Sunfire story, as I've been told that there was some sort of legal injunction problem with anything related to Bob Carver at the time the Sunfire amplifier was available.

(That was Quick!) Some Confirmation...

Sunfire Amplifiers (and the Melos 400)

Another reader sent me his observations about the Sunfire, also positive, and he added his experiences with the Melos 400 as a "bonus". Some minor editing and my bold:

"I can second the letter on the Sunfire amp. I have a friend of decades who designed and built many, many interesting audio devices from amps to preamps to speakers, etc. His classic amp design at the time was a totally symmetrical AB2 triode 2A3 push/pull amp without loop feedback. He did almost nothing with solid state in decades of work. But over a decade ago he had a chance to listen to an early Sunfire amp and told me it was so good that he could only better it by a small amount using every trick he had learned in over 3 decades of hard work. He cited the white paper mentioned explaining that output transistors were most linear when they operated near the voltage from the power supply. We both eventually bought Sunfires and have used them very happily since then.

As long as we're on the subject of interesting amps, here's another one. The Melos 400 mono blocks were tube amps with only four 519 tubes driven through their screens producing 400 watts of TRIODE output of which the first 25 watts were Class A. And the amps had a damping factor of about 20, high for a tube amp, that produced very little frequency variation due to speaker impedance/amplifier output impedance. And in some ways the 400 watts was under rated. The early amps would put out over 700 watts for about 3 seconds, though this was reduced on later production for increased reliability. At $ 10,000 a pair in the 90s they were a steal. High power with triode output is a rare bird. The only other amps that came close (a bit over 200 watts in triode) to similar performance were made by David Berning using a similar tube, the 509, also screen driven."

Personal Note- I asked this reader about any reliability problems concerning the Melos, since I sort of remember some issues, though I have no direct experience I can remember with this Melos amplifier. His reply was...

"They had some problems I think which is why the voltages were reduced in them over time, but they were still always over 400 watts... The 519 was a horizontal output tube and when driven by the screen became a very good triode. The problem was they needed a lot of current to reach full out put. The Berning amp used bipolar transistors as the driver stage to get the current. The Melos used MOSFET cathode followers after the driver stage.

There were a fair number of them made in the 90s but you don't hear much about them now. There was also a one chassis stereo amp rated at 200 watts. The only pair I know now are at a friend's home driving a set of Pipe Dreams. But that's not surprising. ...A friend... was a Melos (as well as Pipe Dreams) partner so I guess I have a bias. But 400 watts of good triode output with a damping factor of 20 almost has to be good." (09/12)

Interesting Updates from Australia

A veteran reader sent me his latest observations which may be useful to readers, especially those living in Australia. Here it is, with minor editing, but with my bold:

"JLTi KT-120 Integrated Amplifier (

Joe Rasmussen of Custom Analog Audio spends most of his time doing a phenomenal upgrade to Oppo BDP-95 and BDP-105 universal digital players, which transforms them into two of the best digital audio players on the planet. But some of his time is spent converting beautifully built, but musically challenged, Chinese valve amplifiers into audio gems. One of these is his rebuild of the Yaqin MC-100B integrated amp.

The input circuitry has been extensively revamped to use 12AT7s, while the output has been completely overhauled to run the 4 Tung-Sol KT-120 output tubes in super-linear triode mode. Much else has been changed besides. The result is a 40 Watt, $ 2,000 integrated amp (switchable to be a power amp), which is competitive with amps costing many times the price. I recently heard a VTL pre/power combo, with a $40K price tag, which I don't think measured up to my JLTi, apart from its much higher power rating." (08/13)

Counterpoint SA-220 Power Amplifier

Decades ago, I was a Counterpoint dealer. I felt at the time, and still do, that they were a highly innovative and value-priced company. I was very sad when they closed down, and I've been on a "mission" since then to ensure that they will never be forgotten. Recently, a long-time reader sent me an email with information that may prove useful for the owners of some of their excellent amplifier models. Here it is, with some minor editing and my bold:

"...My current system consists of a Rega Planar 3 into an Aragon 47k; A Theta Data into an Aragon D2A; those feed the Perreaux SM6 preamp which feeds the pair of Counterpoint SA-220s (as detailed later). Speakers are Thiel CS 2.2s.

Back in the late 80's/early 90's, I bought (new) one of the Counterpoint SA-220 amps. It was from a retailer in CT (I can't remember their name) in a converted old house. So they had several listening rooms, set up in a real house. That was a cool concept that worked well.

Anyway, I went there to audition a pair of B&K monoblocks, which they had modified. At the time, that was the 'hot set-up' as reviewed by Stereophile, whom I was subscribing to at the time. They had them warmed up and ready to go for me, in a small room. It was wide, but the system was across from a couch on the long wall, so distance to speakers was small-ish. (I recall it twice as long as wide)

I brought my (still) reference CD of Robbie Robertson's first record (1987) and listened. It sounded good- certainly better than the Hafler amp I was using at the time. But there was a big, black amp on the rack, sitting cold and idle. So I asked about it. 'That's a Counterpoint. Very nice amps but they require us to sell so many units per month to retain dealer status, an we don't operate like that.' Long story short; I auditioned it, ice cold (only allowing the requisite warm-up mute period) and W O W was I blown away. Yes, it was a bit more (they did discount is slightly to move it), but it was another plane of existence. Same system and room otherwise- just the amp changed, Night and day.

Fast forward a few years and after a move, it wasn't working. So it went back to Mike Elliot for repair. It was an inexpensive repair (broken wire connection) and came back STILL not working- same connection from the transformer was a hair short, and would break during transport vibrations. I fixed it myself with his guidance, and it has been fine (including a couple moves) since. I added some silicone o-rings on the tubes because I got them free from work, and I had the top open anyway. Did it do anything? Who knows...

As you probably know, these can be bridged to monoblocks as well. Something ridiculous like 600W into 8 ohms or something. Borderline welding power supply. Anyway, I happened across a slightly newer (than mine) second SA-220 and contacted Michael to see about possibly upgrading them both or other options which might be available to me. He let me in on a secret- I don't know if this applies to all power amplifiers, or just his design*...

I am using a Perreaux SM6 preamp (which I thought I learned about from your site years ago, but I don't see it there now**) and all the inputs are single-ended; however, it has a set of balanced outputs. From these, I had some Mogami cables made which terminate with un-grounded (shield is floated at the amplifier end) RCA connectors. Per Michael's direction, I connect the "+" to the R+ input and the "-" to the L+ input. Speakers are connected to the "red" output posts respecting similar polarity as input.

This essentially creates a 440w monoblock, rather than bridging, which as I understand bridged amps, also doubles the noise and distortion of the amp. Using this method, the noise and distortion stays where it was/is and the available output power is increased.

A little background: I'm a drummer. Have been since age six in all sorts of bands marching, concert, jazz, progressive rock etc. I have a very good understanding of how a bass drum SHOULD sound. They have a whole lot more 'life' to them than one would be led to believe. Subtle harmonics across the sonic spectrum. Point: This is the first time I have heard bass drum reproduced convincingly. I think, if one has this amp, and can find another (in good shape) wiring them this way is well worth the price of admission." (01/19)

*Caution - Make certain that the circuit of any Counterpoint amplifier is similar to the SA-220 before attempting the reader's wiring experiment.

**I was also a Perreaux dealer in the 1980s. I was impressed with how natural they sounded, especially compared to other transistor designs of their day. Even today, their power amplifiers and preamplifiers (as phono stages) are still listed as "References".






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