REFERENCE COMPONENTS-Line Stages

Any system that sounds better with the addition of an "Active" line stage is an unequivocal indication that:

The vast majority of audio systems require an active line stage. Further, the elimination of the active line stage is a long-term goal that requires each and every component to be optimized and matched with regards to both sensitivity and impedance (and cables for low capacitance). So, to be ruthlessly frank...

This means that most systems, at most times, will require an active line stage.

Finally, never forget that all active line stages are actually "passive" line stages along with (active) amplification. In short- you can't avoid using a passive line stage in any circumstances (unless you want no volume controls). The only issue/choice/decision, in this instance, is whether you want an active stage in addition to the passive.

Always keep in mind that preamplifiers came into existence to equalize and amplify the very low-level phono signals from a turntable. Most tuners and tape decks had their own volume controls, and didn't need a preamplifier when used on their own. Also, many power amplifiers had their own volume control. After CD players became popular, and turntables became relatively rare, preamplifiers became (theoretically) "obsolete" and/or "redundant".

However, rather than lose the sale of a (now) obsolete component, the manufacturers began marketing a "new" component, the "line stage" (which is just a "traditional" preamplifier, but without a phono stage).

They could have placed the line-stage directly within the CD players themselves, which would have been more convenient, economical and even have saved the cost of an extra pair of cables (a sonic benefit too). They predictably didn't. Why? Profits.

Where were the "underground audio magazines" (who were supposed to be looking out for the interests of their readers) while this "transition" was all happening? They were giving "rave reviews" to these (now) expensive and unnecessary components.

The Coincident Statement Line Stage (CSLS) is the finest component of its type that I have ever heard. Much more than that, it is the most "perfect" electronic audio amplifying device, of any type, that I have ever heard. Further, based on my experiences, which are shared below, I believe that the CSLS can never, and will never, be significantly improved on in the future, no matter what the price or the technology used. I realize that these are unusually strong words, but I believe I can, and will, back them up.

First of all, any veteran reader of this website is aware that I don't "like", and, much more importantly, need a line stage. This is why I was very reluctant to audition and review the CSLS, or any other line stage in existence for that matter. Other audio websites (Stereo Mojo and Enjoy the Music) gave the CSLS "raves" and "awards", but that meant nothing to me, due to my somewhat unique circumstance. However, I eventually agreed to review the CSLS (and the matching phono stage), and I finally found the time to start experimenting with it in Fall 2010.

I initially thought it would be simple and fast, like my prior evaluations of other line stages, both active and passive, but this was not the case. This time it was different, and it has taken me a considerable amount of time to figure things out, mainly in an effort to logically connect and match my (and others) personal observations and experiences with the different technologies which created them.

In fact, the entire line stage situation is surprisingly complicated. Let me explain...

I have been experimenting with line stages, and/or their absence, for three decades now. It began in early 1981, when, it is important to remember, line stages, per se, didn't even exist as individual components. They were just one part of a full-function preamplifier, which always included a phono stage as well.

A few months before I opened my audio store, I found myself with the (Mitch) Cotter Phono Stage and the matching Cotter MC Transformer, along with the Audio Research D-150 power amplifier (then stock), along with the original Quad ESL-57 speakers (modified), the Linn Sondek LP-12 turntable and a Denon 103S cartridge (tonearm now forgotten). Despite my best efforts (and even my own brother working for Cotter), I was not able to get the matching Cotter line stage (which was, and is, extremely rare). So, I used the line stages of some high quality full-function preamplifiers (which had their own phono stages), such as the Citation 11, Dynaco PAT-5, Dayton-Wright SPS and ARC SP-3.

Then, one day, realizing that the D-150 had its own volume control, I decided to bypass the line stage I was using at the time, and instead connected the Cotter Phono Stage directly into the ARC amplifier. It was a bit of a pain, since the single stereo volume pot was at the back of the amplifier. Still, I felt the results were well worth it. It turned out that the sound was obviously improved; it was purer, cleaner, faster, more direct and immediate etc. However, due to the relative insensitivity of the Quads, the volume was just too low for too many records, making it impractical, but the seed had been planted. So I committed myself to eventually making a direct connection work, and without any sonic compromises.

After that, there were numerous similar experiments in the 1980's*, in both my store and personal system, but I feel they are redundant, and would like to now focus on my personal situation with the Jadis JP-80 preamplifier, which I purchased in 1989, and I still own today. The JP-80 has been at the center of every experience I've had, with both phono stages and line stages, since then.

*PS Audio designed a preamplifier (PS IV), which I demonstrated and sold in my store, that allowed the user to bypass the line stage with the push of a button.

I first used the Jadis primarily with high-output MC cartridges (it has no MC stage, as does their current "MC" version), until I purchased the Expressive Technology SU-1 MC transformer. Literally overnight, I went from too little gain to having excessive gain, even with low-output MC cartridges. The problem was that the volume pot, using individual resistors, didn't allow fine adjustments below 10 o'clock, and I was usually at 9 o'clock or below, so the music was almost always too loud or too soft. This was obviously highly frustrating.

Thinking things over, I decided to attempt turning my gain problem into a plus by removing the line stage, but this strategy created another problem. How was I going to find out if I could successfully bypass the line stage, without the major hassle of actually bypassing it internally first, and without any guarantee that it would work?

Of course, I could simply use the tape output instead, which bypassed the line stage, but that created yet another problem; the tape outputs also bypassed the volume controls. This meant there would be full volume at all times, which placed both my then amplifiers (Jadis JA-80) and then speakers (Wilson WATTS modified) in serious jeopardy. (The JA-80 did not have its own volume control, as did the Audio Research D-150 in my earlier experiment.)

This dilemma was the inspiration for the creation of The Bolero Test, which solved the problem, and has also helped many other audiophiles since then. In short, the test was highly successful, so I bypassed the JP-80's line stage in 1992. (Over the years since then, I also eventually removed the tape monitor, the mute circuit, the cathode follower section and, finally, the two mono volume controls, which turned the selector switch, in effect, into the "mute switch".)

The (modified) JP-80 preamplifier had now been converted, basically, into a "phono stage". Subsequent experiments, with various dedicated line stages, confirmed that none of them were able to make an improvement in the sonics when inserted into my system. These results were verified by numerous listeners, and not just myself, because I recognized my "animus" towards line stages, which had began a decade earlier (1981). I wanted no prejudices to cloud my observations.

This has been my system's status quo from 1992 until now (though I've made many further improvements to the JP-80 over the years, in both the circuit and the power supply). Then the CSLS arrived...

The CSLS is a two-chassis unit, weighing 74 lbs in total (the power supply alone weighs 41 lbs). The (hard-wired) signal path is a combination of transformers* and one tube (101D), which I've never seen in any other audio amplification device. There are both RCA and Balanced inputs and outputs. Critically important, there are no capacitors or resistors in the direct signal path. It has 20 dB of gain. (For more details and pictures, you can visit the Coincident website.)

I initially broke-in the CSLS with 300 hours of play (using an SACD player), though I now believe that it takes a few hundred extra hours before the CSLS sounds its very best. This is definitely longer than average, and I believe it is caused by the transformers in the signal path.

*The late Harvey Rosenberg is the first person I know of that wrote about this theoretical design approach. Sadly, he did not live to hear its (highly successful) implementation.

As of today, the JP-80 is using only two tubes, both 12AX7. The other four signal path tubes in the stock JP-80 (all 3 in the line stage and the phono stage cathode follower) have been removed. There is one V-Cap Teflon capacitor coupling the two tubes and another (larger) version at the output of the second tube. The RIAA equalization is accomplished with feedback, using Stanley Lipschitz's formula. All the power supply capacitors are film. Only the selector switch is still in the direct signal path, with every other switch bypassed. The volume control, which is resistor based, is now only a shunt to ground, so it is not in the direct signal path. In fact, there are no resistors in the entire direct signal path. This is critical to remember, if the reader's goal is to fully understand and appreciate this review/essay.

So the complete JP-80 direct signal path is now this: RCA inputs - 12AX7 - V-Cap Teflon - 12AX7 - V-Cap Teflon - Selector Switch - RCA outputs.

I am not able to make the signal even purer than the current JP-80, short of removing the selector switch, but that would leave me without a (quick) mute. This is impractical and very dangerous, if not reckless, when using a phono source. Also, experienced readers will now realize that, based on the current signal path, I have only two options when it comes to the volume level; full volume or nothing. That's the trade-off for this degree of minimalism, purity and unprecedented sonics. (It is also an advantage when evaluating passive components, such as resistors and capacitors, and especially line stages, both passive and active, such as the CSLS.)

However, I also created a third option, which I've been using, on and off, for the last decade: I utilized a second input on the (5 position) selector switch for the phono output, but this time I put a (high-quality) resistor in series with the signal. This option will reduce the volume level by a fixed amount. The selector switch then, depending on the position, provides me three choices:
1. A direct, full-volume output, with no resistor, or
2. A "Mute", or
3. An output that is slightly attenuated, because the signal goes through one (high-quality) resistor.

This discussion of the signal paths, selector switches and resistors may all seem like excessive and irrelevant detail, but it is just the opposite. The ultimate performance of the CSLS, for better or worse, is all in relation to, comparative with, and dependent on the performance of the JP-80 itself. This is because we are not going to compare the CSLS to just another line stage (as in every other serious review), but, instead, to the source itself ("perfection").

In other words, we are going to make the ultimate comparison; A Bypass Test.

There is no tougher, and more revealing, test than a bypass test. This is because the "standard" or "ideal" is not the listener's "taste", or a memory, or an alternative component in a normal A/B comparison, which would have its own strengths and weaknesses. This time the standard is "the source", which can be considered effectively "perfect", even though, in reality, it is not. Of course, the better the source, the easier it is to hear it being degraded. However, in the final analysis, the source takes the place of "perfection", because any audible deviation from the source, by the component being tested, is a deviation, in effect, from "perfection". In other words, the closer the component comes to mimicking the source, the fewer flaws it has, and the closer it is to "perfection". The inverse of that maxim is also true. It is as simple as that.

Unfortunately, only one actual component, the line stage, is capable of a "bypass" test, because it can be successfully bypassed in a system. The same is true with some signal cables, but nothing else in the signal path (amps, speakers, cartridges etc) can be bypassed, only compared, which can never be as revealing and/or effective. It can be very difficult to arrange a bypass test, but that is no excuse to ignore them. If you never seem them mentioned, let alone performed, in the mainstream magazines, there is a good reason for this. Bypass test are TOO definitive because of their objective and revealing nature. There will be real and unavoidable sonic problems that are exposed, as well as "winners and losers", and the magazines, these days, only want to declare winners, and certainly not dwell on component deficiencies.

Now, to remove any potential confusion, I want to make clear what I mean by a "bypass test", with an easy to understand example, and then I'll discuss the CSLS bypass in particular. Imagine a six foot speaker cable is under consideration. The question: How close does it comes to "perfection"? (Which I define as "no cable", or a direct connection of the amps with the speakers.) This is a difficult, but not impossible, test to accomplish. (In fact, one of my associates has already made this exact same test in his own system, and then later successfully eliminated the speaker cable in the process.)

First, the mono amplifier is placed directly behind the (electrostatic) speaker, with only a few inches separating their respective binding posts. The speaker is then opened up. The speaker's (six inch) internal cable (attached to its binding posts) is now unattached. Instead, this same internal cable is directly connected to the amplifier's binding posts. Thus, there is now a direct connection of the amplifier and speakers, and without the need of any external cabling. (If the amplifier's own internal cable is long enough, it can also be used to connect to the speaker's binding posts. So there are two potential methods of accomplishing this type of direct connection.)

When the system is then next played, the performance, for better or worse, becomes "the standard". It doesn't matter that it is not "perfect". For our testing purposes it is "perfection", because any sonic change we observe, when we later actually connect and use the six foot speaker cable under test, is a deviation from "the standard" (regardless of whether it is liked or disliked).

Finally, when it comes to conducting a line stage bypass test (in contrast to a cable), there is one critical assumption we must make; That the source, whether it is a phono stage, a CD/SACD player, a DAC or just a tuner, has the full capability, on its own, to successfully drive the input stage of the amplifier, and the connecting signal cable, without any sonic compromise(s).

"The Source" consisted of the JP-80 connected to the Coincident Frankenstein M300B amplifier(s) with a six foot length of (prototype) interconnect cable. I used a 1 meter Coincident Extreme Interconnect cable (CEI) to connect the Jadis to the CSLS, and the same prototype cable to connect the CSLS to the Frankenstein amp. So, both the CSLS and the CEI were added to the signal path. Accordingly, any and all deviations originated from the combination of the component and the cable.

An attempt will be later made to separate the respective sonic "culpability" of the two "additions", but the major point here is this: Never forget the fact that when adding a line stage to a system, the system will also be adding an extra cable along with it.

The Deviations of the CSLS and CEI combined:
1. A touch of "immediacy" and "gut presence" and "nakedness" is lost
2. There is a tiny bit of "rounding" on sharp transients
3. Images are slightly "laid back", around 4 to 6 inches
4. A touch of "air" is lost

Where "The Standard" and the CSLS/CEI combination sounded basically indistinguishable (to me):
1. Bass; extension, impact, control, detail etc.
2. Dynamic contrasts, shifts and intensity, at all volume levels
3. Soundstage size, focus, separation etc.
4. High frequencies
5. Sound-floor
6. Everything else, not mentioned above or below, that I've (temporarily) overlooked

Where the CSLS/CEI sounded superior to "The Standard"*:
1. A touch more natural harmonics
2. A tiny bit purer (mainly at high volumes)
3. Bodies of instruments (and singers) slightly more realistic and solid, and less "fun house mirror"
4. Sound is somewhat more effortless, as if the amplifiers have more power

Before discussing the above in detail, it must be emphasized that all the changes, for better or worse, are quite subtle, meaning an average person, with no interest in audio, would probably not hear them. However, any experienced audiophile should be able to observe all of the above. In fact, three friends actually did hear the above differences (and similarities) in my system.

*This means that "The Standard" was not capable of fully driving the connecting cable and the input stage of the amplifier, despite my incorrect assumption that it had this capability. However, I can and will defend myself below.

There is a lot to digest from these results, and with many important implications that can't be avoided and will be discussed, but I would like to first focus on the deficiencies of the CSLS, since that will usually be the primary focus of most audiophiles:

It should be no surprise that, since no component is figuratively perfect, the CSLS has some audible deviations (or deficiencies), but what is truly important is both what they are, and their minimal degree of audibility. What is surprising is that the deficiencies are limited only to those areas that are always compromised when there is extra cabling added, which is exactly what happened in this instance (the CEI and the CSLS signal path transformers). It's almost like the actual CSLS amplifying tube had no deleterious effect at all, or at least none observable by us (so far).

Actually, after some contemplation, I believe that I've heard similar deficiencies (in kind and in degree) when simply going from a 1 meter cable to a 3 or 4 meter cable of the same type. Accordingly, I'm amazed that these problems are all that I can report on the downside, but I believe I can do even more to accurately describe the degree of the deficiencies. This is where all the prior discussion above, specifically about resistors, will now become highly relevant.

Readers will recall that there was an option on my Jadis JP-80 which allowed me to slightly attenuate the output by having the signal go through one resistor (which was then connected to one of the inputs of the selector switch). So this resistor was in series with the signal. The value of the resistor, which changed depending on the system requirements, was usually 20K or 50K. The resistor manufacturer and series was the: Vishay VTA. This particular resistor is considered to be one of the finest in the world, meaning it does a minimum amount of audio degradation, and it costs around $ 10 each.

I, along with a number of my friends, have a lot of experience (10 years worth) listening to the effects of this one resistor on the signal, since I only had to move the selector switch two places to make a comparison (Direct - Mute - Vishay 20K). Since no resistor I know of is perfect either, this finally brings us to "the big question": How does the imperfect CSLS compare to the imperfect Vishay VTA resistor?

This is easy to answer: The Vishay resistor's sonic "presence", and its sonic problems, were far easier to hear than the CSLS. The type of deficiencies of both are quite similar, but the amount of those same deficiencies is not similar. The Vishay VTA easily crosses the "threshold of hearing", even when one is not listening for it. This is not the case with the CSLS. I would like to be as specific as I can...

I would estimate, using a numerical scale, that the Vishay is approximately three times easier to notice. In other words, in bottom-line listening results, the CSLS has around 35% (+/-10%) of the Vishay resistor's sonic problems. I can't be more exact than that, since I am not an infallible machine.

However, if personal, anecdotal observations will further help in this instance, I can add this: Whenever I went from "direct" to the Vishay, the degradation was obvious. The reaction was immediate and dramatic, especially from other listeners; "What happened?" etc. You didn't have to listen for the problems (as with the CSLS), because they were literally impossible to ignore, at least for an audiophile. In fact, I have ended up rarely using the resistor option, because "too loud" was still preferable in almost all cases. So, "three times" may even be conservative, but the CSLS degradation is, at the worst, around half that of the Vishay. That is what must be taken away.

I am going into this amount of detail for several reasons; this allows any reader, with Vishay resistors, to repeat my experiment for a total cost of $ 20. It is also a further verification of my observation of how little the CSLS adversely effects the signal, and finally, it quantifies my use of the words "touch" and "tiny", when I initially described the degree of the CSLS's deficiencies.

I made this claim in the first paragraph of this review: "the CSLS can never, and will never, be significantly improved on in the future, no matter what the price or the technology used." If I observed any component, and not just a line stage, deteriorating the signal by only 35% as much as a high quality resistor, how could I believe, and write, anything other than that about that same component?

There's not much to say here, but it's important to note that, in most ways, the CSLS and "the source" are essentially the same. That is significant in this particular case. However, while I, and other listeners, were not able to hear other sonic differences, even when listening for them, it is still possible that I/we may hear some differences in the future. The important point is this: If they are eventually heard, they will be, by definition and in practice, inconsequential. If this were not so, they would have already been heard and described.

There is one other critically important observation to note at this time, which is directly related to why I mistakenly* assumed that "the source" was fully capable of handling the next stage and, consequently, could not be improved upon. Something occurred that was without any precedent in my audio life, both in my personal system or any other system I've ever heard.

(*Further- My preamplifier's output capacitor and volume pot values have both changed in the last decade. Plus the amplifiers and cable length have also changed in the last few years, effecting the load of "the next stage". That's everything!)

To be specific, within "the indistinguishables" there are both "bass" and "dynamics". In all my years of experience using line stages, and removing them, it has always been these two areas which have been the most effected (read "compromised") when a line stage, if necessary, is not in the system. In fact, listening for compromised bass and dynamics is the primary test to discover whether a line stage is a system requirement or not (mainly because any related problems are extremely easy to hear).

And this experience is universal, since one can read literally hundreds of listener posts complaining about "the lack of bass and dynamics" when switching to a passive system, or when using a direct connection. Accordingly, it never dawned on me, because it had never occurred in the past, that the source could retain the bass and dynamics and still be sonically compromised. This means it's possible that a line stage can make a sonic "improvement" even if and when it does not also "improve" the bass and dynamics.

This naturally leads us to the next subject, which required some (speculative) thinking on my part...

We will first briefly discuss the particular "improvements" we observed with the CSLS (already described above), and then we will tackle the larger subject of (line stage) "Improvements"; focusing specifically on how and why they even occur in the first place.

In general, the sound, overall, with the CSLS in the signal path, was a little more "natural" and "realistic". It was certainly not a "significant" change, let alone "dramatic", but it was noticeable. The instruments and singers had a little more natural solidity and harmonics, and the sound was a little cleaner and more effortless. It was almost like the VTA was optimized after being slightly off, along with a little more amplifier power. Nice, but it's not a big deal on its own. However, I believe that it is a "big deal" that any "improvement" was noticeable.

This brings us to the critically important issue which lies at the heart of this review/essay. This subject, which is usually avoided in favor of personal anecdotes or, even worst, completely ignored, must be seriously addressed at this time, even if no answer or understanding can ever be completely satisfying to everyone.

This question, or subject, has been in the back of my mind, as some type of unsolvable dilemma, for many years now. Accordingly, I must take this step by step, and start with some basic definitions and descriptions of the relevant fundamentals. Without this basic context, we can go no further.

First of all, when I used the word "improvement" above, it was always with quotes (""). This was not an accident, because a line stage can never literally improve a signal. Such an improvement is figuratively and physically impossible in our world. Require some proof?- If it was actually possible to improve, or enhance, the signal, then two line stages would have to be even better than one, and three even better than two, and so on to infinity (resulting in sound better than "live").

If a literal improvement is then absurd (and illogical), then what do we actually experience when we do hear a line stage "improve" the sound of a system (that was previously without one)? It is certainly a given that we all agree that what we hear is real, and obviously not just our imagination, or wishful thinking.

What a (properly operating) line stage does is to enable* the (existing) signal, from the source, to fully drive both the interconnect cable and the input stage of the amplifier, and without any compromises. By "compromises", I mean that the line stage must overcome all the fundamental (and usually easily observable) problems which are caused by not having a line stage in the system. To be specific, they are: (Problems with) Volume, Bass, Dynamic Energy and Body.

(*Just as an output transformer will enable an amplifier's output tubes to drive the speaker, or a MC transformer will enable a low-output MC phono cartridge to drive a MM phono stage.)

In other words, if the line stage doesn't even enable the source to fully drive the load, then it is a failure (period), and must be removed and replaced. All that should ever matter to the listener, when evaluating a particular line stage, are that line stage's own (unavoidable) deviations (type and degree), which will be observed when the said line stage is used. And, needless to say, the better the system, the easier it will be to hear those deviations (such as the examples I listed above).

So, to answer the above question, the line stage sounds superior to a direct connection because the source, on its own, usually fails to fully drive the load, and thus requires an "enabler" (the line stage). And so we come to the next related question/issue...

Part Seven- Why then does the source usually fail to fully drive the load?

The answer to this question is straightforward (and self-evident): It can only be because the signal from the source lacks the type and/or amount of energy required to drive the (combined) load.

This then brings us to a discussion of these specific signal source "failures". This requires some speculation on my part, since I don't believe anyone has all the answers as of today. Here are the typical sonic problems, which are directly caused by these failures:

Lack of Proper Volume- Needless to say, any system without enough gain, from the source alone, to reach a satisfying volume, must obviously use a line stage. However, sheer gain (or volume), from the source, is not enough, on its own, to avoid using a line stage! Just as critical is where the gain is located in the signal path...

Example- My (stock) Jadis JP-80, which had both a MM phono and a line stage, had enough gain (volume), on its own, for many MC cartridges, but it sounded absolutely horrible (distorted, compressed, lean etc). Why?- The line stage gain was "too late" to "save" the (delicate MC) signal, which had been already "damaged" trying (in vain) to properly drive the MM stage. This is why the MC transformer, I later purchased, which was designed specifically for ultra-low level MC signals, when combined with only the MM stage, sounded so much better than just the MM and the line stage, even though the total gain was almost exactly the same for both combinations.

This "gain location" (or position) concept must be understood. The total gain of the MC/MM was the same as the MM/LS, but one of them sounded outstanding, while the other sounded horrible. So pure numbers, in this case total gain, are only half the story, and not definitive.

Roll-off of Frequency Extremes- This is very easily heard by most listeners and it's also easily explained, even if you don't have a technical background (and I don't). In most instances, the cause will be an impedance mismatch between the source and the load, so one, or both, frequency extremes will be rolled-off, and sometimes dramatically (most of the bass). There are actual scientific formulas for these impedance induced roll-offs, which are, in effect, filters, though unwanted in this case.

Compressed Dynamic Contrasts- This is also easily heard, even by non-audiophiles. Further, it is critically important to understand that compression is independent of volume, because "loud" does not have a direct correlation with uncompressed dynamic swings, especially those that can startle you with their intensity. The root cause, once again, is that the focused energy of the (source) signal is "lost", or "disbursed", when it attempts to drive the load (by itself). The sonic result of this failure is a bland, "dead" and boring reproduction of the original recording. And simply raising the volume won't bring the music back to life. Dead is dead.

Compromised Harmonic "Relationships"- This is a much more subtle problem to observe, though if it is pronounced, the sound will lack "body", which is relatively easy to hear. What was new (and unexpected) for me was the hitherto unobserved problem with harmonic completeness, which I only noticed after the line stage was installed in the signal path. A serious problem, such as a lack of natural body, can be easily explained by a roll-off, and/or a lack of low frequency energy from the (weak) source, but what about the missing upper harmonics?

My working theory is that when a signal (from the source) is too weak (on its own) to successfully energize the load, the "relationship" of the fundamental frequency, with its related harmonics, will be "shuffled" (like a deck of cards). In effect, mixing diamonds with clubs and spades with hearts. So, while the information may all still be there, the ear won't here it because the relationships have been changed, and it then becomes just "noise" (to ignore), instead of related sound (music). A line stage, if working properly, will avoid all of this.

In effect, the "structural integrity" of the signal is the first thing that goes when the signal from the source lacks the adequate energy for the load. It is not easy to hear, because it is subtle compared to the other sonic problems that usually accompany it during this failure.

Less Purity- This is also a subtle observation, and it's also less common (though I experienced it in my own system). This occurs when the sound of the system is actually cleaner with (then without) a line stage. That observation would appear to be a contradiction, if not impossible, on first reflection, since additions to the signal should always mean additional distortion, not less. However, there is a logical explanation for this: It must mean that the inherent distortion of the line stage is less than the increase in distortion caused by the source (unsuccessfully) trying to directly drive the load of the input stage.

How and why this makes sense- A line stage is a lot like an output transformer in a tube amplifier. The transformer is also an addition to the signal path, but it still reduces distortion (and many other problems). In addition, even if an amplifier has more than enough power for the speaker, distortion will still be noticed if the incoming signal is compromised because it couldn't drive the amp's input stage.

Our highly surprising experiences with the Coincident Statement Line Stage (CSLS) have profound and highly unusual, if not contradictory, implications. On one hand, my overall perspective on (the use of) line stages, in general, has not appreciably changed. However, on the other hand, much of the underlying theories, details and real-world practicalities, which are (and must be) the foundation of any serious and rational advice concerning this component, have been forever altered. Let me explain...

I still believe that a direct connection, between the source and the amplifier(s), when usable, is, and always will be, the ideal method to achieve the highest fidelity to that source. However, there is one serious and unavoidable "fly in the ointment" with this method, which must be addressed. Even if a direct connection is possible (without any sonic compromises), and extra gain is not a requirement:

How do you then change (optimize) the volume level without also compromising the signal (sonics)?

The answer to this critical question lies in the observations within this review...

From my perspective, one of the most important observations, noted in this review, is that a single (high quality) resistor did more harm to the signal than an entire line stage which, critically, did NOT use a resistor based volume pot. Instead, the line stage used an ultra high quality transformer based volume pot. So, the first "rule" is crystal clear:

Avoid all resistor based volume pots*, either in a passive or active line stage (and I would also most certainly include the source itself in that "rule").

*Thorsten Loesch was the first audiophile, I know of, to claim that resistors deteriorated the signal much more than transformers, when discussing volume pots, especially in passive preamplifiers. I was originally skeptical of his claim, but he has been proven to be correct, as I admitted, on this website, years ago.

Next, when specifically evaluating the CSLS itself, I can now state that it is possible to build an active line stage, which is available commercially, that does noticeably less sonic harm than just one (high quality) resistor. This is obviously a "breakthrough" of sorts, at least in my experience, with line stages or any electronic component for that matter. There is nothing, I'm aware of, even approaching the performance of the CSLS at anywhere near its price, and while it may be understandably expensive ($ 5,000) to some, it is also far less costly than many other line stages (while still being far better built).

Further, from my and others experience, even the vast majority of those more expensive models will also not approach the CSLS in performance, despite their (far) higher price. (A single resistor, anywhere in their signal path, will automatically disqualify them.) Ultimately, even if a "perfect" line stage became available (at some unimaginable price), it would only slightly, and insignificantly, outperform the CSLS, based on our (acid and merciless bypass) tests.

1. If a line stage is a system requirement, and the CSLS is affordable (even many times over), then I would purchase it, and only it, and without any qualification. Even if it's a "reach", I can guarantee that the CSLS is well worth it. The CSLS is the closest thing to a "straight wire with gain" that I am aware of, and it will never be significantly superseded in pure sonic performance. (If a remote control and/or LED display are "priorities", then this is the wrong website.)

2. If, for budgetary concerns, the purchase of the CSLS is impossible at this time, then I would get the Doge 8 (which also has an excellent phono stage). As far I know, there's nothing else that is remotely close to these two models available today, for both ultimate performance and value (including their build quality). If a reader is prepared to purchase a used component, the Pass Labs Aleph L, discussed in Class B, may be attractive, and it should sell for under $ 1,000 (but they're rare and hard to find).

3. What if an audiophile is certain that they don't need an active line stage? Then I would look for the finest transformer based passive line stage that is affordable. I would avoid all resistor based passive line stages, no matter what their price, reputation or claimed performance. (The Lightspeed Attenuator may be another excellent option, but we have no experience with it.)

4. What if an audiophile still doesn't know yet, for certain, if they need an active line stage, or not? Then I would either use:

A. The Bolero Test, if the system already has a line stage, to discover whether it can be successfully removed from the signal path. Or...

B. Borrow a high quality line stage if the system has never been tested with a similar device in the signal path. The "bottom line" is simple: Every audiophile must be certain of the signal source(s) drive capability, one way or the other.

5. When using any line stage, active or passive, you must be certain that all the sources are playing at full volume. This will then mean that they have no (extra and harmful) resistors in their signal path.

I decided to purchase the Coincident Statement Line Stage. This is the first time I've had a line stage in my system since 1992, so this reflected a serious change in system direction and strategy, and not just a routine switch/upgrade of components. This was my reasoning:

The CSLS slightly improved the performance of my system overall, though that subtle improvement, on its own, was not large enough for such an investment and change. However, three further benefits made the decision for me.

1. My system would now have enough gain to play all of my low-cut records at natural volume levels, which was not true without the CSLS.
2. I would also have the ability to play all my records, and digital software, at the most optimum level, which was also not true without the CSLS.
3. I'm now able to directly bi-amplify my speakers without using the Cotter Noise Filter Buffer, which slightly "dried-up" the bass frequencies. (The Cotter was necessary if the Jadis, on its own, had to drive two amplifiers per channel. I used it only for the bass amplifier.)

Explanation- The only method to reduce the volume level, with the Jadis by itself, is to put a (resistor based) volume pot in the direct circuit path, which will adversely effect the performance (as I describe above), unless I use an outboard transformer based volume control. So the three options I had were clear:

1. The status quo- This means having only one volume level (all-out), which is either (somewhat) too low or too high for a good deal of my software. I can only lower the volume by compromising the sonics with a resistor based volume pot. I would also have to accept and live with a slightly lower level in performance (versus using the line stage). Further, I would still have to use the Cotter for bi-amping. Finally, I would have no extra gain for all the software that was too low in volume.

2. An outboard transformer based volume control- This option would allow me to attenuate the signal if it was too high, and without compromising the sonics. However, it offers no gain for all the records and digital software that are too low in volume. Further, the sonic problems (described above), caused by the inability of the Jadis to fully drive the amplifier input stage, would still be noticeable, and I would also still require the Cotter for bi-amping.

3. The CSLS- Which allows me to play all of my music, whether cut too high or too low, and also fully drive the amplifier load, now and in the future, which means the sonics will always be optimum, under all circumstances. Finally, I can even bi-amplify without the Cotter device in the direct signal path.

The Bottom Line- There were too many important and practical advantages for me not to go with the CSLS. My current problems are not only completely solved, here and now, but also in the future, because the unprecedented performance of the CSLS effectively removes any threat of obsolescence from the equation. How often does that ever happen, in audio or virtually any technology serving people?

Lenco Reference Turntable
Graham Phantom II Tonearm
ZYX UNIverse Phono Cartridge
Bent Audio Silver MC Transformer
Jadis JP-80 Preamplifier (converted into a dedicated phono stage, and highly modified)
Coincident Statement Line Stage
Coincident Frankenstein 300B SET Amplifiers
Coincident Pure Reference Extremes (Doubled Up)

The records I used the most to evaluate the Coincident Statement Line Stage were:

Bach-Mass in B Minor-Richter-DGG Archive 2710 001 (Voices, Body, Focus, Harmonics, Decays - My Most Played Album)

Dutilleux/Lutoslawski-Cello Concertos-Rostropovitch-EMI ASD 3145 (Harmonics, Body, Immediacy, Dynamics, Bass, Space, Image Size, Decays)

A Medieval Christmas-Boston Camerata-Nonesuch H-71315 (Voices, Body, Space, Focus, Decays, Image Size, Harmonics, Immediacy)

La Spagna-Atrivm Mvsicae de Madrid-BIS LP 163/164 (Speed, Purity, Immediacy, Harmonics, Decays, Depth)

This technique will always be the most optimum and least compromised method of transmitting the signal, both in theory and in practice, BUT, based on my own lengthy and relentless efforts (see above), it is extremely difficult to achieve.

For a phono system, this means that the phono stage must be directly connected to the amplifier(s). Eliminating the line stage in a system with a turntable/phono signal source is more difficult and also more musically rewarding than with a non-phono system. I know this from more than 15 years of first-hand experience with my own system.

The main problem to overcome is that many phono stages, especially those with tube amplification, have both a relatively low-level signal and a high output impedance. This is an awful combination which makes it very difficult for them to directly drive the power amplifier(s).

In a CD system (or tape, tuner etc.), the analog* outputs must be directly connected to the amplifier(s). There is a much greater chance for this scenario to succeed compared to a phono system. The fact that it still fails, in many (if not most) cases, is because the analog stage of the CD player (or DAC) is not properly designed.

In many instances, this "failure of design" is done on purpose. The reason is to force the owner to purchase a separate line stage, hopefully from the exact same manufacturer of the ill-designed CD player or DAC.

* Digital volume control can not be used in this test. They adversely effect the amount of musical information leaving the source.

There should always be at least an attempt to connect a single source directly to the power amplifier if possible; using a CD player or DAC’s (or phono stage's) analog volume control etc., even if the volume pot has to be installed. (See The Bolero Test just below for sources, and amplifiers, without volume controls.)

Even more ideal is a volume control at the input of the power amplifier. This would eliminate the need for the volume control within the source to also drive an interconnect. If there is more than one source and there is no selector-control, then you must audition a high quality passive line stage (see below).

Also important are the interconnects, which must have low capacitance in this instance, or the frequency extremes may be noticeably rolled off. Making sure these cables are as short as possible may even make the difference between success or failure.

NOTE- There obviously must be a volume control either within the phono stage, at the CD analog output or at the amplifier input for a direct connection to be even functional.

If the system has more than one source, a passive line stage (meaning there are no transistors or tubes in the signal path) will almost always be required. It is not quite as "pure"* as a direct connection, but it is more practical for most audiophiles.

*The compromise is essentially the necessary addition of an extra interconnect cable in the signal path.

Fortunately, passive line stages can be easily built by non-technicians. More and more kits are available using high-quality volume pots, selector switches, RCA females etc. Even paying someone to build one should be economical, since the parts can be purchased directly. Based on my experiences with the Coincident Statement Line Stage (discussed above), I only recommend using transformer based volume pots, and would entirely avoid using resistors.

Important- Accept in rare instances, the use of a passive line stage will not overcome any compatibility problems that already existed when directly connecting the source to the amplifier. It simply adds multiple-source flexibility, that's it.

I was a dealer of this line for a few years in the middle 1990's. This was their most impressive component, by far. While I felt the Aleph amps were good, though very overrated by the audio press, this preamplifier was totally ignored by these same 'reporters'. Too bad, because this was a highly innovative design, beautifully executed and just might still be the most desirable line stage ever made for most systems. The entire Aleph line was discontinued in 2000.

The most original feature of this preamplifier, never duplicated or imitated by anyone else, including Pass Labs themselves, is its automatic Passive/Active signal routing. If the audio system doesn't need more gain than the signal source provides, the Pass will not further amplify the signal. This is achieved by a unique volume control.

The volume control operates passively up until 3:00, and after that it is active. The change between passive, and active, is automatic. Most of the time the volume control will operate below 3:00, which means the Aleph L is, in effect, a high-quality passive preamp, which will always outperform any active design if there isn't an impedance/sensitivity mismatch. Above 3:00, the Pass automatically becomes active. It then slightly dries out the sound, while also adding a thin veil. That's excellent performance, but not outstanding for an active preamplifier.

At exactly 3:00, in another innovative design feature, the preamp even removes the volume control itself from the signal path, making it as pure and simple as technically possible, with the single exception of a direct connection. The end result is a preamplifier that will compare with the finest passive units ever made, while still offering up to 10 dB of high quality gain if still required.

The Pass has 4 inputs, two ouputs, a single volume control, a selector switch, is on all the time and is built like a proverbial tank. I used it for a number of years (1996-2001) with outstanding results in my retail store. It was superior to every line stage of every preamplifier I heard during that period. It's a perfect marriage of true high performance and practicality. I understand they are now going used for less than $ 1,000. That makes it an incredible bargain.

Caveat- The earliest version of the Aleph L did NOT have the active/passive automatical volume control which makes the later version unique and special. The early models are NOT References. The Aleph L is also not for those who want maximum "convenience". It does not have a remote control.

I will be adding some components within this class as soon as I confer with my associates.

More than 15 years ago, Spring 1992, I had a dilemma. I had recently purchased the Expressive Technology SU-1 Transformer and was finally able to use a low-output moving coil (Monster Alpha Two) cartridge with my Jadis JP-80 preamplifier.

The initial problem was that, with the Expressive transformer, I had too much gain, even with the Alpha Two. (The Jadis' stepped resistor volume control couldn't be adjusted precisely at below 9 o'clock.)

So I decided that maybe the line stage of the Jadis could be removed. That would reduce the gain and (hopefully) also improve the sound as a bonus. However, I didn't want to physically remove the line stage first, which was a lot of trouble and work, and then find out that I didn't have enough gain without it, or had other unforseen problems. So I would have to play a record first, without going through the line stage, to find out.

How is that done?
Simple; the signal going to the amplifiers would now come from the "tape outputs" and not the usual "main outputs". However...

There is one BIG problem with this approach; you can't adjust the volume since the signal, now coming from the tape outputs, will bypass the volume controls along with the line stage. This means that if the signal is too strong, which is a distinct possibility, it may damage your amplifiers, speakers, hearing etc.

After some thought, I realized that I had to find a record with music which could inform me, with plenty of time for reflection, whether or not I had:

1. Sufficient gain,
2. No compromise in the quality of sound and,
3. Still not pose any threat to my system (or myself).

Bolero starts off extremely softly, perfect for safety, but slowly builds up and ends with a sustained crescendo, with the entire process taking more than 10 minutes. That is plenty of time to decide if the gain of the system is adequate. There are also a variety of instruments to listen to, making this an excellent test of the quality of the system when not using an active line stage.

This is the step-by-step process to test the system, using Bolero, with the minimum amount of risk.

1. Find and play Bolero on your system in a normal manner, meaning with the main outputs and at your typical listening volume. Remember the volume and the sonics carefully. The exact position of the beginning of the Bolero cut on the record must also be remembered.

2. The amplifiers must then be shut down until the I.C. cables going to them can be removed without danger. The preamplifier can and must remain on.

3. Then reconnect the amplifiers to the tape output of the preamplifier. Don't turn the amplifiers back on yet.

4. The preamplifier's selector switch should be on the source that is just "one click" away from phono, so that the phono input can be switched in (and out) with one quick movement. This other source will now become the de facto "mute" position. The preamplifier must NOT be on the Phono input when the stylus is placed either on or off the record. The new "mute" position will now be used on these occasions.

5. Make absolutely certain that the source selected as "the mute" has no signal going through it. (A signal can cause serious damage.)

6. Now the amplifiers can be turned back on and warmed up. (If there are any "strange noises", then shut the amplifier off, and check the connections and/or sources. Remember, the volume control is now totally useless at this point.)

7. After the amplifiers are warmed up, put Bolero back on the turntable and cue the stylus. When the stylus is "secure" within the groove, then (and only then) switch the selector control to "Phono". You will now be hearing the record without the line stage. (You may also hear a "pop" when making the switch, if your selector control has a problem.)

8. Now you must listen carefully until you know exactly what is happening. Here are some typical scenarios:

A. You may notice either immediately, or after a while, that the volume is too soft compared to your normal listening level. That's it. There is no use going forward. Your phono stage does not have enough gain to drive the (relatively) insensitive amplifiers and/or speakers. This system, as presently constituted, requires an active line stage, and there's nothing more to say or do.

B. You observe that the system is louder by a large (easily noticeable) degree, than your usual listening level. The next step is to listen for the quality of the sound (before Bolero gets too loud). You will want to know if anything is "lost"; like dynamic expansion, deep bass, body, impact etc. If nothing is "lost", you can now go to the next stage, removing the line stage entirely, or bypassing it, with confidence.

C. If the volume is around the same as the "reference", or just a little bit louder, you must realize that this will be the maximum volume level after the line stage is removed (with the current system). You will have to now decide whether or not you can live with this upper volume level. Once again, you must also listen to the quality of the sound. Further...

If "C" describes your situation, you should also play other records (making sure to always use the selector control as a "mute" first), to verify your impression of the results. You should particularly choose records that were cut with a lower volume, so as to discover the potential "bad news" immediately.

In my own experience back then, the output without the line stage was still quite excessive, so I removed the line stage the next day and I had incredible results. The sonic improvements were staggering to me, and I have never used a line stage since then (though I have tried a number of them).

The same test can also be used with CD players (without volume controls) using Bolero. Once again, you connect the CD player directly to the amplifiers (using the same caution) and put on Bolero. You can also still go through the preamplifier's tape outputs. You don't need a "mute" input with a CD player, just use the stop button. Then wait for the results. Just make absolutely certain it is Bolero, or the same potential dangers, described above, will apply.

If you don't fully understand the entire procedure, or it just seems too difficult or risky, then do not attempt this test. This test is meant for veteran audiophiles. I will not be responsible for any problems, of any nature, caused by its use, or more likely, misuse.

I have used this test personally, or on other people's systems, around a dozen times, so I know that it works, but only if properly executed. In the past, I always explained it, face-to-face, to experienced audiophiles, who understood the procedure. I can't control who will read the above steps, but it's definitely not for "beginners", or anyone else who isn't certain what they are doing.

Channel Islands Audio PA-1 Passive/Active Preamplifier- A reader sent me this good news about a possible successor to the Aleph L discussed above. Here it is (edited):

"I wanted to mention that the Pass Labs Aleph L has been imitated, contrary to what your article says... it has been imitated by Dusty Vawther of Channel Islands Audio/Monolithic Sound here: http://www.ciaudio.com/"

Personal Note- It is called the "PA-1 Passive/Active Preamplifier", and it retails for $ 599, compared to $ 2,000 for the Aleph L when it was new. While the basic design is the same, and even the basic appearance is similar, the active circuit is probably different, as well as the power supply, transistors, passive parts etc. So the sound, at least in active mode, will also be somewhat different, but this is still a model that anyone, at any price point, should look into. It's the most logical method of amplifying a line signal. Maybe they'll even come out with an "all-out" model one day, although they already offer an updated power supply (HC-1b, $ 279).
Bonus- There's even a "30 day/no risk trial", so you can find out if the preamp works in your system without a monetary risk.

BAT VK-3i LINE STAGE- A reader, who has sent this site a considerable amount of information about the MFA Luminescence, has recently tried using the "Lumi" as a dedicated phono stage, and the BAT VK-3i as a line stage. Here are his (edited) observations:

"(I) had a chance to live with a BAT VK-3i line stage. Surprise-surprise: it has general tonal balance of a Lumi (not an easy task as it uses 6922 tubes) but outperforms it in every respect. It is clearer, more resolving, more dynamic and very palpable. It is no surprise that these sell like hotcakes on the used market ($800 plain, $1000 with remote, it was $2K new). It has Jensen paper in oil 1 mF output couplers, which are extremely transparent, but which roll off the bass slightly (-3 db at 20 hz, -0.5 db at 63 hz, but can be easily fixed by replacing with 3 mF). BAT offers a capacitor replacement, but instead of giving you just one 3 mF cap, they put 6 X 0.5 mF caps in parallel - smart thinking but expensive.

I used the Lumi's phono stage to drive the BAT and it sounded great. Lumi's downfall is actually it's line stage. Before I stick it in the closet I want to try oil caps in it and see if it improves anything. I tried all expensive caps in it and now run Hovlands, but I'll try Infinis today. Doubt they will make a difference. BAT's high frequency resolution is excellent. I find it much more "real" sounding that all the Audio Research gear, Audible Illusions etc. BAT also makes a solid state phono board for it (so-so) and a separate multi-tube phono stage* ($ 2K) which takes most MCs with no step-up. I heard it in my friend's house and it was good. I'm getting it soon for an evaluation. I also heard the Classe Six Mk II. Excellent preamp for the money (with MM/MC phono) - can be had for less that $1K, but it's flat, no dimension."

*BAT Phono Stage- In another letter, this same reader has some further observations about the BAT phono stage he promised above to evaluate in his home. Here they are, with some minor editing:

"After prolonged listening, the BAT (phono stage) proved to be ultimately fatiguing. And, though excelling on acoustical stuff, the BAT can not realistically portray big band or rock or complex classical. The Lumi is never fatiguing, albeit much less exciting and really good with big demanding stuff. So (the Lumi) stays for now. "

Personal Note- I also feel that the strength of the MFA Luminescence is its phono stage. Its line stage is still very good, especially in reproducing body and tone, though it is slow, rolled-off and lacks immediacy. This lucky reader appears to have found the "best of both worlds", and without spending "big money".

More Recently After reading the above comments on the BAT VK-3i line stage, another reader had some of his own observations to share, while also introducing a new model from this same manufacturer. I felt his (edited) experiences were relevant and important:

"I have read in the ("Recent File") of one of your reader/associates experiences with the BAT VK-3i preamplifier. I owned one of these for 2 years, 1998-2000. At the time I thought it was quite good. And in fact, I think this unit has been the best selling unit that BAT has produced. When Victor redid his preamps in 1999, he kept the 3i in the lineup because they were his best selling product at that time.

I replaced the 3i in August 2000 with a newer preamp from BAT, the VK30SE. This preamp was a real step up from the 3i in tonal quality and soundstage presentation. The 30SE was much smoother, (as) the 3i in comparison was rather solid state sounding, and the 30SE had a much larger sounstage presentation than the 3i, which was much smaller. This VK30SE was the preamp in my system until I made my little passive unit."

Further observations from this reader- The same reader had some experiences with a home built passive line stage he also shared:

"...I have finally taken your advice and dispensed with the preamp in my audio system. I designed (although there's not really much designing involved) and constructed a passive pre with a shunt stepped attenuator. I do have a selector switch for inputs, but have the main input direct to the attenuator. This made one of the largest fundamental differences in listening that I have heard!!!! Musical details heretofore unheard were suddenly all THERE. I was so stunned that I reconfigured the system with preamp back in just to be sure I was not mistaken. And sure enough, with the preamp in the system, the details disappeared. Out went the preamp to collect dust, and eventually on to another owner. Total cost for my little gem was somewhere in the neighborhood of $200-250. I used Elma switches and Vampire OFC connectors and wire. I used a Vishay S102 resistor for the shunt resistor. And according to Guy Hammel, the Placette guy, one really needs Vishay S102's in a passive controller for best results.

All (is) well and good with the preamp, but I do not listen to records or pop/rock type musics, so therefore my comments on the passive controller are a bit limited. But certainly for one who only listens to classical musics with a digital input player, a preamp just covers up the details. And details are what classical music is all about. The change with the passive controller is so dramatic, that even discs from Deutche Grammophone now sound quite detailed and complete. And I must add that with the passive pre I did NOT suffer any of the loses, bass and dymanics, often noted with passive units. I hear all the music just as it was recorded." (9/04)

Personal Notes- This reader heard the benefits of using a passive preamp because his system did not have an impedance mismatch between the source and his amplifier, which would normally require an active preamp to overcome (along with the sonic price of the active). In my own system, I've used both Vishay and (the much less expensive) Holco resistors. At this time the cheaper Holcos work even better for me, but both are recommended in the inevitable attempt to optimize the system.

CONRAD JOHNSON ART LINE STAGE- One of my associates heard the CJ ART line stage 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 both lean and a little dry. From my perspective above, I recommend avoiding active line stages, but if I didn't, the ART would be near or at the top of those we've actually heard.

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

MUSIC FIRST PASSIVE MAGNETIC PREAMPLIFIER- A reader sent me a letter stating that he was "surprised" that I still hadn't mentioned this in my "Other Interesting Line Stages" file. He's right, I should have mentioned it. This model, along with the Bent Audio version (below), is the best solution to those who want a passive preamplifier, but have an impedance mismatch with their source and power amplifier(s). This will solve that problem, and can even give you a few db of gain.

They achieve the impedance matching by the use of high-quality transformers. The resistor passive is still potentially the least harmful to the signal, but it only works in a small minority of systems (such as mine).

BENT AUDIO TAP PASSIVE PREAMPLIFIER Basically the same performance as the above. This isn't strange because they both use the same exact transformer. Both models are nice looking and well built. This model is put together in Canada, while the Music First is made in England.

One of best-engineered passive line stage offerings was the "Mod Squad Deluxe Line Drive AGT" designed by Steve McCormack. This can be found used for just a few hundred dollars. A later model, the McCormack Micro Line Drive, was also v. good. It had 3 inputs, a tape monitor and both a passive and active output.

The current, in-production successor to these products is the McCormack Audio RLD-1. It goes for $ 1,700 new, has a remote and is available with an optional MM/MC phono stage.

Here's Steve's thoughts on his passive designs:
http://www.hometheaterhifi.com/volume_2_1/passive.html" (9/06)

Personal Note- I, and one of my associates, also had some positive experiences with the McCormack passive and active line stages. They are also reasonably priced, especially when found used at a discount.

Here's part of a letter from Thorsten Loesch, who's made several valuable contributions to this website over the years. Thorsten takes issue with my prior statement of the comparative weaknesses of the two types of passive preamplifiers; those with resistor-based volume controls (which are also my preference) and their transformer-based equivalents. There's some minor editing, and my bold:

"There is a DIY unit (DIY HiFisupply Django as option) and several commercial units (Music First Audio PMP [also with silver wound transformers!], Bent Audio/Music First TAP Audio Sector T-Pre, AVTAC Pasiphae) that all use the Stevens & Billington TX-102 Attenuator Transformer.

This transformer, and the TX-103 Step-up you found so good, are both developents from Stevens & Billington's TX-101 Studio Line Transformer, and where initiated and specified by me (also with quite a bit of design input), and developed to the current form by Jonathan Billington of S&B, with input by Bent Audio's John Chapman and myself. In many ways the performance of the TX-102, a simple "line" transformer, is the same as the TX-103 used as stepup.

I would like to also take some issue with your statement: 'The resistor passive is still potentially the least harmful to the signal, but it only works in a small minority of systems (such as mine).'.

During the initial development of the 102, many comparisons where made to "true ladder" attenuators, which had only two Vishay Resistors as voltage divider per position. In fact, the attenuators in question included the Audio Synthesis "Passion" passive preamplifier, which uses a single fixed Vishay resistor in the series position, and switches only the shunt resistor.

Martin Colloms, in his technical review of the MFA PMP in HiFi News, also compared the PMP (copper) to his Audio Synthesis Passion, and found the MFA PMP notably superior. To mention that HiFi News selected the £ 1,500 MFA PMP as "Product of the Year" two years running, with the runners-up being the £ 5,000 active designs by Conrad Johnson and Musical Fidelity's best last year (not sure about who the runners-up where this year), is redundant, except for noting that no-one was bribed or any other kickbacks given.

So no, the resistor is still, and remains, the more harmful solution to attenuating the signal, when compared to a truly high quality attenuator transformer. That this fact has gone mostly unnoticed is simply down to the fact that Music First Audio and Stevens & Billington (as well as Bent Audio) concentrate on making exceptional products, NOT on marketing, getting loads of positive reviews and pump tons of money into advertising. You should try a transformer based passive preamp one of these days, you may find that it gives a lot better SSS (Shared Sense of Space) than resistors..."

I still have an open mind on this subject, but I think everyone should know why I originally wrote that resistors were less harmful to the signal than transformers. (And please remember that I emphasized that they "only work in a small minority of systems...")

1. Two (or even more) of my readers have had the Bent TX-102 in their systems, or its English equivalent, and informed* me that they preferred their passive volume controls, which they felt were "less noticeable". That's why I haven't already approached John Chapman of Bent Audio about borrowing one of them. I realize this contradicts the observations of Martin Colloms, but I don't give Mr. Colloms any more credibility than I do my readers, despite his experience.

*Their letters would be routinely posted now, but back then (2003/4) I rarely posted reader's letters.

2. Then there's my experience with moving-coil transformers and resistors in the signal path of my own system. This is A/B/C logic, so you will all have to bear with me. I have continually had resistors in and out of the signal path on the output of my preamplifier (phono stage) for years now. (I don't like the Vishays too much, even though they have this big reputation, along with their price. I actually prefer the much cheaper Holco.) Every resistor I have tried has noticeably degraded the signal to some extent.

However, I felt the signal degradation of any of these resistors (one resistor in series with the signal) was noticeably less than the degradation of the copper Bent Moving Coil transformer compared to its exact silver equivalent. Now, even if the silver MC is considered "perfect", for the sake of argument, this is still proof to me that the copper transformer degrades the signal more than a resistor, unless it's "apples and oranges" comparing a line transformer to a MC transformer. If Thorsten has an explanation for this, I would like to hear it, and post it.

Right now, I don't use even one resistor in the signal path, so the Bent, or the MFA, is useless to me. (I play my system at full volume on every LP because of the low output.) This may well change in the next few months, so I'm prepared to take the necessary steps to optimize this new reality. For the sake of clarity...

My phono signal path goes from the 2uf V-Cap Teflon output capacitor, with a 10M load, directly to the selector switch, where it then goes both directly to the output RCA female and also the volume control, where the only variable is the resistance value to ground- from 0 ohms up to 250K ohms. I effectively use the selector switch as a "mute", never touching the volume controls, after the first LP, up until the very end, when I place the volume back to "0" for further protection.

Finally, I invite any readers with actual experience on this issue (or "controversy") to send me their observations, which I will post. I promise to protect your privacy as always, and I only ask for complete sincerity in return. (12/06)

ELECTRONIC VISIONARY SYSTEMS "ULTIMATE ATTENUATORS"- These are high quality volume controls (or shunt attenuators*) which attach directly to the amplifier's input (RCA Female or XLR). They eliminate the need for line stages, either active or passive, assuming of course that the source can directly drive the amplifier (a big assumption). This is the way to go if you have ONE SOURCE. A link is provided below and in The Links File.

*A "shunt attenuator" has only one (or no) fixed resistor in the signal path, and only the resistor value to ground ever changes. This is the least harmful method to change volume, in theory. In fact, this is the exact technique (with no fixed resistor) I use in my own system. However, there is a potential risk, because the system's ultimate frequency response may change (for the worse) if it can't handle the varying impedances, which can be too low at times. (12/06)

Below are two letters I combined from a reader who has made previous contributions to this website. There's some editing, plus my bold:

"I have had a Django Classic passive-magnetic preamp (http://www.diyhifisupply.com/diyhs_django.htm), which is very similar to the Music First Passive preamp, and is based on S&B TX-102 transformer. Maybe my experience with this type of passive preamp is peculiar, but I have had a lot of components mismatch with it, and I have tried it with many components in many systems. I have sold it because I was tired to continually search for a good component synergy.

So my point is that these passive-magnetic preamps may not work easily in everybody's system, and may not be the best solution either for a passive preamp. However, there is of course the possibility that all this is related to my own unit. I did not try other passive-magnetic preamps.

I have used the Django not only in my system, but also in many others, so with many different components (different sources, different amps, different speakers (but always high-efficient ones)).

So I made the comment not only based on my experience in my system, but also based on my experience in other systems. Sometimes it works (and even that it is not perfect), but the vast majority of times it was so-so or awful. Maybe the critical point is having different sonic priorities than Mr. Loesch - or at least it is an hypothesis."

Personal Notes- This is an example of one more letter from a reader who has had negative experiences with a transformer based passive preamplifier, which I mentioned in a December reply. This is from my reply to this reader:

"I still prefer using a resistor based volume control myself, but I recommended the transformer for those who can not use regular volume controls, so I agree with your observations and advice. I'm glad you sent your letter, because my contributor, Thorsten Loesch, still feels that transformers are always the best method for passives, and I believe he is wrong."

I don't know how anyone can reconcile the observations and perspective of this reader and Thorsten, along with the Martin Colloms review in Hi-Fi News, let alone their "Product of the Year" award. (Unless the Django is a complete piece of junk, which doesn't appear very likely to me.) The only reasonable solution I can recommend is a thorough trial before purchase, which shouldn't take that long. I feel the same way about resistor based passives. With all the variables involved, some of them unknown, there's potential for both great success and disastrous failure. (1/07)

This letter is from a reader who had the courage and trust to remove the active line stage in his system, using the "test" I describe in the line stage file. There's only some slight editing, and my bold as usual:

"I sent you an email several months ago regarding my positive experiences with the Bolero test (using a Rotel CDP, Vandersteen 2ce Signature speakers and a McCormack DNA 0.5 amp). So, I just thought I'd give you an update on my experimentation. Since writing to you last, I have purchased a Promitheus Transformer Volume Control from promitheusaudio.com (link below), a very small company in Malaysia. I purchased one of the reference versions at a price of $420 plus shippping, which seemed to be a reasonable price for my experiment. The TVC replaced a Rotel 1062 integrated amp.

I guess it should come as no surprise that the TVC has resulted in a huge improvement in sound vs. using the Rotel as an integrated. I loved the sound when I ran the Bolero test with my CDP and amp, and I'd have to say that what I'm getting from the TVC is very similar if not better. I'm not one to throw around words like "decay" and "speed," etc., when describing stereo sound (I'm simply not fluent in audophile speak), but I can describe the results as follows:

1. Improved bass using the TVC over the integrated. Deeper.
2. The sound is extremely natural. I won't say that it sounds as if the orchestra is right there in front of me; I don't think my Vandersteens are capable of that. But the tinniness I had been experiencing is gone.
3. The TVC is especially impressive with solo voice and single instruments (I mostly listen to piano). But listening to the Karajan CD of Parsifal the other day, I was impressed with the realism and depth of sound of the orchestra, especially during the second half of Act 1.

Of course, I have limited stereo experience. The Rotel integrated is the only thing I can compare the TVC to, other than my experience with attending concerts. The TVC has moved me closer to that experience. Clean sound, improved bass and realistic separation seem to be the major attributes of the TVC. Oh, and voices are more forward (in front of the orchestra), too. As for volume, as anticipated, no problems. The volume control has 24 steps, and I usually play music at six or seven clicks.

The Promitheus TVC, by the way, is a simple wood box with stainless steel tops and bottoms. Inside are the transformers and a network of wires.

Maybe I'm imagining that the sound is less electric (because my brain knows that there's no electric running through the TVC). But I did an A/B the TVC with the Rotel on an unknowing wife the other day, and she picked right every time. I've since sold the Rotel integrated and will probably sit tight with my system for a while (unless a good deal on a Vandersteen 2wq subwoofer comes along)."

Another reader has experienced a highly successful result when he eliminated the line-stage (and more) of his (excellent) preamplifier. I love these letters, because more than anything I could ever write, they may help to encourage other audiophiles to experiment for themselves. There's nothing to lose, and so much to gain (for free!), if the remaining components are compatible. There's only minor editing, and my bold as usual:

"...Your efforts to articulate sound reproduction concepts are generally not well understood by most audiophiles. I refer to your thoughts on "sound-floor" and "low level information".

I have been seriously listening to some kind of high-end audio since about 1975. Due to budget constraints, I have not spend a lot of time with very high priced equipment and most of my listening has been done with modified vintage tube electronics. The modifications included replacing capacitors with the best I could afford. Over the years, I have owned the Conrad Johnson MV-75, the Dyna PAS, a Linn, a Well Tempered Table, many cartridges, Maggies, and a variety of home made speakers. Of course, the results have varied widely, depending on the equipment, the quality of parts I could afford, and the inherent design limitations. I was rarely satisfied, however the sound was usually better than what I heard in the local high end salons.

In your writing, you describe the improvements that you hear when you reduced the number of parts in the signal path, between the source and loudspeaker. Your writing on eliminating line stages is a great example, and I recently put your ideas to good affect in my system.

I have an Atma-sphere MP-3 preamp. After listening using the both the phono stage and the line stage, I decide to try the phonostage connected to my power amps through a passive preamp, that consisted of a 10K Caddock resistor and a 250K pot to ground, to adjust the volume for each channel. This combination had enough gain to give me loud enough music, and the increase in low level detail was very noticeable. Everything was better, the bass, the soundstage illusion, everything. After reading more on your website, I decided to eliminate the 10K Caddock resistor. Wow, another amazing improvement. I had no idea how obviously colored that resistor was.

I then began to think about the pieces of wire, and the switches, that remained in the signal path in the phono section of the MP-3. It seemed logical that those extra parts had to be effecting the signal. I opened the preamp and connected short lengths of wire directly to the output of the phono board. I ran those wires to a phono jack that I mounted on a bracket inside the preamp. Mounted on the bracket, with the jack, is a 100K pot to ground (no resistance in series), to adjust the volume. The result was a much simpler signal path.

This is the cat's meow! The phono stage sounds great wired this way. Until I heard my LP's through this setup, I had no idea how much very delicate musical detail in all frequency ranges was being retrieved by the cartridge. Before this modification, all that information coming from the cartridge was being masked by the extra wire, contacts and the line stage itself. By the time it reached my loudspeakers, it was gone.

My system consists of a modified Thorens turntable and arm, with a cheap Grado cartridge, the Atma-sphere Phonostage. The passive volume control signal goes to two stereo amps. One is a modified Eico push pull EL-84 amp, driving some dipole ribbons from 300hz up, and the other half of the signal goes to an equalizer, and an electronic crossover, driving dipole woofers (ala Linkwitz), with a modified Harmon Kardon Citation II. Not even close to state of the art, but with the line stage eliminated, the sound is amazing."

Personal Notes- This reader has basically duplicated what I did with my own Jadis preamplifier. The only difference is that I use a 250K pot. Sadly, I recently had a similar highly positive experience when I removed a 50K Vishay resistor from the signal path. Maybe Thorsten Loesch was right after all about the inferiority of resistors compared to transformers.

Here is a short write-up of the new, all-out, Prometheus Transformer Based Passive Line Stage. The two letters, which are combined below, are from a veteran reader. There's very little editing and my bold:

"My Signature TVC preamps from Prometheus Audio have arrived a couple of days ago. Unfortunately, my bottom copper plates are bent, which Nicholas suspects is a form of shipping damage, so I cannot mount them on the included ebony cones. Even as they are, they sound incredible. At $1,600 I think they are very good value by YOUR measure. The are dual mono/dual box to minimze crosstalk and maximize channel separation. Large custom double c-core transfomers, elna switches, etc. Prometheus is serious about this product.

My system is currently in an interim state. Still the Scoutmaster/JMW-9/Empire MC5/Wright Sound WPP200C phono front end, and an unmodded (for now) MHZS CD88E digital front end. Speakers are DIY crossoverless Audio Nirvana full rangers at around 97 db/w/m in room. All cables are Speltz solid core Anti-Cables. Amp is the better integrated Sonic Impact II T-Amp, until Prometheus develops its Signature transformer coupled 300B SET amp.

Adding the Signature TVC (and an extra set of interconnects) has been the single largest improvement to my system. The extra detail is obvious across the spectrum. The tonal accuracy appears to be excellent, and the decrease in homogenization is probably at least significant, so that individual instruments are better spatially and sonically isolated. Imaging is better too. For the first time ever I now have sound that I now consider 'high end', and I wouldn't be embarassed to have an experienced audiophile listen to it even if I'm still short of Class A territory.

The best example of what I've heard in these first few days is a CD I have of older Louis Armstrong. The benefits of the TVC are very apparent when he sings scat. Whereas before I couldn't really understand what he was signing, it is now quite intelligble, remarkably so.

The older TCV model from Prometheus were found to require 400-450 hours to fully break in. Nicholas Chua, the man behind Prometheus, feels his larger double c-core Signatures will take noticeably longer, but I've yet to see any figures. Based upon the improvement noted in these older models, I should be in store for noticeable improvements. But they sound excellent right out of the box. Perhaps Thorsten (Loesch) was right as you've wondered.

One note about Prometheus. They are victims of their own success, so they are sometimes a little slow to respond to emails and don't always make their expected shipping dates. But as others have mentioned online, I've found Nicholas to be honest and trustworthy, and with this level of performance and value I can live with a little frustration.

For an entry level system, getting one of the basic Promiteus TVC models used on Audiogon and mating this to a T-amp of some variety and a pair of DIY Audio Nirvana high efficiency, full range/crossoverless speakers is certainly one of the most cost efficient approaches to developing an economical yet revealling system. I dare say you would be surprised what this combination, which is likely less than $1,200.00 and only requires sources and cable, will do.

As for me, who has been more a Class C/buy used type of person, the $1,600 Signature TVCs are far and away the best component and value I've ever purchased. These will go to my grave with me.

In my haste to reply, I neglected to add two important observations about the Prometheus TVCs, both positive. Firstly, they have a very articulate sound, which my wife criticized as being 'too sharp' (i.e. Lifelike). The 'shape' of the notes is very distinct, and I think this is into the arena of outer detail if I understand the term. There is no sonic blurring of the notes. Whatever it is, it adds a significant element of realism to the music. Secondly, I noted a significant improvement in decay, which caught my attention on piano pieces especially. The resonant properties of the piano notes is quite attention-grabbing, and the prolonged decay of the notes again has a very realistic portrayal.

I likely won't have time to do a detailed assessment of the Signatures for a while, as they will have to be returned to Prometheus for repair. But they are an excellent component and certainly worth your attention." (2/08)

I have no experience with this model, and neither do any of my associates. However, a veteran, experienced and helpful reader sent me his detailed observations. The reader's first language is not English, so I did my best, within reasonable time constraints, to help with the grammar. Here it is, and the bold is mine:

"I would like to post some listening impressions about my new preamp that I purchased last year. It's the long-awaited unit from ARIA, a new brand owned by Mike Elliott, (ex-Counterpoint designer) very well known for many outstanding preamps in the 1980's. My choice was the WV11XL, a tube line stage only (but there is also available a full unit with MC phono, costing only $1,000 USD more), so my report refers to the line stage and not the phono (I do have an external SA-9jr unit from Counterpoint).

The unit has now reached approximately the full burn-in process required by the manufacturer (200 hours), and the sound is more cohesive and sweet. Please refer to the manufacturer's website for the complete specifications. All the listening sessions were made testing alternatively both the RCA and XLR connections. The remote is a cheap piece controlling the volume knob only. The construction is excellent and the finishing looks equal to the best competitors.

I have made some listening sessions in comparison with a few excellent preamps (see below), both tube and solid-state, using three different power amps:
BAT VK-55 first version;
EAR 509 monos;
Counterpoint-AltaVista NP220 (premium plus level),
These power amps have three different sounds, with EAR's apparently more vivid and dynamic, but much less refined. The BAT has a nice tonal balance (the best of the three), but it has limited power in the bass region when it's pushed hard. The speakers are my Kharma CE.2.3, with ceramic drivers for midrange and tweeter only. In this contest, the hybrid tube-SS NP220 is preferable, with more depth in the soundstage, and better definition and beauty on voices. It's also the most powerful of the three, with better control in the bass.

Preamps I had in my room for a comparison in the last year were the: ARC REF 1, Spectral DMC-20; Mark Levinson ML-26 and ML-320; BAT VK-51SE; LAMM LL2 Line Stage.

I understand that these are not the current flagships for each brand, but all of them are highly regarded preamps with very very good tonal balance, detail and flexibility. Some of these were better concerning the not important feature of the control range in the volume pot (steps of 0.5 db for BAT). The Spectral, as expected, more thin and one sweet spot; Lamm a little bit dark in tonal balance, ARC and ML-320 with a nice sound in all spectrums. The overall sound quality of the Aria WV11XL is just in another class; better on every parameter, sometimes with a little margin, sometimes with a large difference. You hear immediately a more lifelike presentation of the music. You have great and superior resolution of low-level details, both of the musicians playing and also the small ambience noises are clearly much more audible than the other preamps, and contribute to create a more lively performance.

The SPL variations of program music seems effortless, but at the same time musicians and singers remains in their place on the stage; superb depth and great sense of air. Music appears more cohesive. To my ears there's not a part of the frequency spectrum that is better than another; high frequencies are obviously extended, clear and not compressed, but never never fatiguing. You receive the involvement in listening that sometimes you obtain through different tubes designs that do their best in midrange resolution, but here, with the Aria, you have more speed.

It's not as fast as the Spectral (most preamps and power amps from Spectral are the fastest on the market), but at the same time you have IMHO a correct decay of the music, not slightly truncated as I have listened with some SS preamps. This is easy to hear, not only with solo performers (Oistrakh's violin on Bruch Scottish Decca 6035 seems now in perfect tonal balance), but especially when the music becomes complex, as in the most part with great symphonies, with many musicians.

For each comparison, I waited until the solid-state units remained turned on for at least one day before judging; but with other preamps in every match the general sensation is of nice detail and timbre, but less vivid sound; you play good music, you have detail but... you are two steps back. Please note that the comparisons have been made detaching for a few minutes all systems before start again. Units for comparison remained in my home from 3 days up to 2 weeks for listening.

Vinyl and CD were used alternatively; all kinds of music, with 50% classical (both symphonic and small scale); and the rest of jazz group and pop. I know very well the character of some of the greatly loved labels, like old Mercury's, RCA, Decca, etc. I do have a large selection of vinyl rated in your Supreme Recordings, so some of the discs of that list were used for listening.

The design circuit of the ARIA is unusual; a small switch allows the use of both 6 and 12 volt tubes; so... you can enjoy tube-rolling. Each change caused different gain, and also the tonal balance and soundstage will vary. I know only one other preamp that has a similar feature; it's the Italian Lector model Zoe (but this latter has less tubes). I'll try it in my home soon.

Actually the Aria comes with good new EH ECC88; until today my preference goes to old Tung-Sol 12BH7A black plate, but I have not tried yet all the long list of compatible tubes. I had a further little improvement with some rolling in two (of the four) tubes in the power supply section.

I gave attention to the choice of power amp input impedance. My EAR 509 were modified raising a value of 100K ohm; BAT given from a friend of mine is 215K ohm and NP220 is approx. 500K ohm. This last is a perfect match for a tube preamp that has a declared output impedance of 2-3000 ohms approx. I had the opportunity to try the huge and well reputed VITUS 101 SS power amp, but I refused, since the input impedance value is a prohibitive 600 ohms in balanced mode (a value that seems typical in professional market). It is impossible for Aria to drive it without losing high frequencies and dynamics.

My opinion is that the ARIA WV can probably easily compete with the best products on the market. I'm thinking of the most famous tube competitors, like ARC REF5, or the BAT REX. Sure it's possible that some other little brand may do better in some aspects, just for example, I read something enthusiastic about new Joule Electra 450 Marianne Electra, as well the Audion Premier Quattro and Jadis JP-80* you quoted on your site. Also, here in Europe, we have a few small brands with great reputations for their best preamps. Since I made any comparison side-to-side, I can only suppose that the WV11XL from Mr. Elliott will be in the same league.

About price, I can't make any consideration, since a brand that has the direct sales service only should be clearly cheaper than competitors that sell through dealers, I don't want to analyze this problem, for now." (12/09)

*Personal Notes- The Jadis JP-80 is a "Reference" on this website only for its phono stage. I have bypassed the internal line stage completely (in 1992). Consequently, I have no idea how it would compare to other line stages, even if heavily modified.

I'm also not surprised by this reader's observations of the Aria, since I, and other serious audiophiles, felt Counterpoint (Michael Elliott) produced better components than Audio Research or CJ (and others), when they were in business, in both absolute terms and "for the money".

This is what I wrote about this important subject a few years back, but still feel is relevant...

It happened again. Another concerned reader wants me to hear the latest ("best") active line stage in my own system. He's positive that it will make an improvement, since I'm "only" using (in effect) a passive preamplifier (my Jadis JP-80 preamplifier's selector switch and volume controls- the stock tube line stage having been removed and bypassed 16 years ago).

Here is a small part of what he wrote to me: "I am coming for you. I agree with you 100% that the active preamps from the 80s and 90s are inferior...".

The reader's argument then boils down to this: I avoided using an active line stage all these years only because their performance was relatively poor compared to my passive line stage, but once I hear an "outstanding" model, I will go back to an active.

More importantly, the actual performance of an active line stage is not even relevant to whether it is needed in a system or not. Since other readers may also be confused about this critical issue, and because it appears that I haven't done a good enough job with "The Bolero Test" to help audiophiles understand and answer the line stage question), I will try again, but this time from another angle:

This test is very simple. If you are currently connecting a phono stage or a CD player directly to an amplifier, or through a passive device (and then to the amplifier), simply add any decent active line stage, or replace the passive device with any decent active device (it doesn't have to be "the best"). Once this is done, then listen to the results. The Rule...

If there is any noticeable and obvious sonic improvement with the active line stage, then you need an active line stage. It's that easy. All that's left is the most difficult part, choosing the model that you like the most.

What this reader (and many other audiophiles) doesn't understand is that the quality of the active line stage is not critical when it comes to making the determination of whether you need an active device or not. What is critical is whether the source (CD player and/or phono stage) has the required output to drive the amplifier directly (beyond simple volume needs). It either does or it doesn't. This is black and white.

Most sources do not have the required output. When they don't, it's extremely easy to expose their sonic weakness(es). In fact, virtually any active line stage (short of total "junk") will sound better in some noticeable manner (deep bass, dynamic intensity, more natural "body" etc). (It will also sound worse in some manner, but that is irrelevant at this point.)

Alternatively, when the source does have the "required output" (which is my present situation), then no active line stage, no matter how good it is, will prove to be superior in any noticeable manner. In fact, it will rarely even equal the sonics of the direct connection in any manner (because of all the extra cabling, connections and an imperfect active circuit). Even a theoretically "perfect" active line stage can only equal an equivalent passive line stage with the required output, because they both must share the same passive parts (volume control, selector switch, wiring etc).

In the case of my own system, once I realized, through actual listening experiences, that no active line stage of the day (early 1990's) could improve on what I was hearing, in any manner, than I knew that no future active line stage could alter that fundamental paradigm, no matter how good it was. This was because my source had the required output. The best I could ever hope for in an active line stage would be something that sounded very similar to what I had, but with more gain. The quality of the sound could never be improved on. If it could, I would have heard some improvement 16 years ago.

The above "test and rule" is based on multiple experiences, not only in my system, but in many other systems I am/was familiar with. It is NOT some speculative "theory" I've put together for some irrational or egotistical reason, and I've never heard any exception to this "rule". So...

In short, if you need an active line stage because your source is not up to the task of driving the amplifier(s), then...

Any good active line stage, from any era, will improve the sonics in some obvious and clear manner.

Alternatively, if your source is up to the task of driving your amp(s), then...

No active line stage, no matter how good it is, will ever equal the sonics of your direct connection (or an equivalent passive).