Holographic imaging


Hi folks, is the so called holographic imaging with many tube amplifiers an artifact? With solid state one only hears "holographic imaging" if that is in the recording, but with many tube amps you can hear it all the time. So solid state fails in this department? Or are those tube amps not telling the truth?

Chris
dazzdax
Rebbi, Regarding your comments about the frontal plane of the sound v the frontal plane of the speakers, and Tvad re your view supporting Rebbi's definition of 'holography', in my limited experience I have found that putting sound out in front of the plane of the speakers is more related to speaker design (I have only experienced this phenom with a horn/cone hybrid and it a general soundfield attached to most recordings. But it was facinating especially with that old Carver 9 holograpy machine in the loop).

But I have only heard 'holography' (my version) with cones and a few recordings, but I haven't heard horns in many years - certainly not since I developed a lot more sophistication about this process. Wish I had those old horns back so I could listen to see if they would sound better than cone drivers in this respect.

Oh well, too much too doo about seeing rare birds. :-)
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I have been strongly considering trying a real tube pre on my system.

I prefer the tube voiced output on my SS Carver pre to the SS one on my system currently. I'm thinking it could add a useful ingredient to my audio soup, maybe just a small pinch of additional "bloom". I've considered Acoustic Research, CJ, Unison, VTL, and DeHavilland.

Classe is one brand of SS pre that I would also consider trying from what I've heard.

I'm open for suggestions on this if anybody has some.
Not to beat this thread to death (probably too late for that ;-) ) but to me, soundstage and imaging are what happen between and sometimes to the right and left of right and left speakers, respectively (as in, "Those speakers throw a huge soundstage)" whereas "holographic" refers to the sense that sounds and instruments are "out in the room" closer to you than the plane of the speakers.

How much of this is about the speaker and how much is about deliberate or inadvertent artifacts of the recording process I don't know.

I just picked up a copy of "When I Look Into Your Eyes" by Diana Krall. On one of the first two cuts (can't remember right now) there's a piano entrance that eerily seems to envelop the listener all around the listening position. I don't know if it's "realistic," but it's impressive and in my book, "holographic."

YMMV, as they say.
Learsfool,
stupid of me, I should have thought of adding horns to the list of speakers which do best in the fields which are being discussed here. Thanks for reminding us. Thanks also for pointing out once more the importance of the recording engineers and their miking and mixing techniques. I often wish, Mohr and Layton were still around.......
Hcat apparently sounds interesting to the untrained ear.

Let the guy go; he's championed other suspect products as well. Most of them flavor of the month products like this one.

Check the posting history. It's all there.
The best holographic imaging I've experienced is through a Vac Avatar driving B&W speakers. There's something about cone based speakers and tubes that deliver a full sonic image that literally dances in front of you. I'm not sure I would always contribute holographic imaging to good sound staging though. It seems you can get a realistic, pin point sound stage but not necessarily have it be 3D if that makes any sense. Overall tubes tend to solidify stereo images better than solid state but I wouldn't say it's an absolute. I've heard some pretty good almost 3d imaging from a solid state amp but with a tube-pre. Room acoustics also play a big part along with the low level detail that others have brought up.
TBg,

Believe me I'm not interested in arguing either, but realize that the definition I provided is not mine, I'm just sharing it. Take it for whatever its worth.

I'm just trying to help provide some clarity in terminology where it exists so as to help cut to the chase rather than argue what certain words mean.

Personally I learned from it that Carver holography really isn't holography at all. Its just one engineers approach to providing a bigger sound stage with improved 3-d imaging if that is to someones tastes. Obviously, its not to many, at least via the means provided.
Just found this thread today. My first thoughts on reading through it are that this thread hilariously proves just how many different definitions there are out there for these terms that audiophiles like to use. The only way to be absolutely sure that we are speaking of the same thing would be to be in the same room listening together.

That said, I think atmasphere has done an excellent job of describing what most people mean by them, with the exception of bloom. I have never before now heard that term described as coming from distortion, though I have heard it described as "coloration," which I suppose could be reasonably argued is the same thing. However, I think both Detlof and Newbee have more accurately described the phenomenon of bloom, which does naturally occur, particularly in a good hall.

I would also agree that tubes and horn speakers are still the best way to hear this particular aspect of sound recreation, especially of an orchestra in a great concert hall. I would add, though, that the recording engineers and their mike placements and mixes have a huge, not to be underestimated effect on this. I have been a part of many live orchestral performances that sounded amazing only to listen later to a recording made by a well-meaning engineer who got it amazingly wrong. And if that happens, which it does far more often than not nowadays (not to start this argument over again, but digital recording has a very great deal to do with it), even the very best system out there, no matter what type it is, can't fix that. If I had a penny for every audiophile who lost faith in a system or component when the actual fault lay with a poor recording.....
Pubul57, live music IS more dynamic, especially if you are hearing it without amplification which is difficult to find. If you are as close to the performance as the microphones, you would hear great holographic imaging.

Mapman, I have no interest in arguing your definition of holographic. I have seen holographic visual images. This is my definition of an audio holographic image.

As I have said before I have owned omni speakers and heard the MBLs repeatedly over the last 20 years and in a friend's home. My present non-omni system is much more holographic.
Newbee, Mapman,
I do see your point. Sometimes it is better to have a pleasant hand- or earful, instead of hunting for an abstract principle. In fact I do appreciate the Penelopes, but I won't forget the Sophias either.
Happy listening
Back to Dazzdax original inquiry, I suspect the tube-associated artifact in question is not holographic imaging and more likely what is commonly referred to as "bloom".

I don't think that holographic imaging is an artifact of tubes at all. Bloom often is. I would agree with Dave also regarding the relative sonic merits of bloom in general and how it becomes less of a distinguishing factor in better gear.
Newbee,

My eyes tell me that I would also much prefer to see Penelope Cruz.

Hopefully my eyes are not as deluded as many seem to think are my ears.
Detlof, Yes, perhaps, but to much truth isn't always a good thing! In this day & age, I'd much rather see her at a distance with her clothes on! When in Spain I keep looking for the street where Penelope Cruz lives. Now there is 'real' wisdom. :-)
TBG,

Agreed that there is a thrill to realism in an outstanding performance.
Mapman, I agree that we make our own choices based on what we hear. I get no holographic presentation from omni directional speakers but do with my LaCampanellas and the H-Cat electronics. I suspect that all of us are interested in the music, but there is a thrill to realism in an outstanding performance, that I have always sought, but again some may not seek this. Need there be further discussion?
Newbee,

I'm undetered because I've heard a lot of variations of very good live and reproduced sound over the years and know that there are many ways to skin a cat. We each make our own best informed choices.
"There are many ways that lead to Rome....."

And some of them pass right by Sofia's house, and you pause to think of her as you once did in the past. :-)

Lets face it, very few recordings were made in a fashion that I believe is required to set up the possibility that an audio system might produce a sonic hologram, as I would hear it.

As a pratical matter most everything we hear is the result of multi-miking, mixing down, compression, often by a low-end recording engineer in an anechoic studio or an unoccupied symphony hall (an echo chamber perhaps?). So if we are happy with our systems when it can reproduce this music well and even remotely remind us of a live event we should be content.

Mapman, You've got the right idea. You know what you hear, you know what you believe, and you're undetered by anything which might threaten your sonic/intellectual illusions. We should all be so fortunate, but we chase dreams anchored in the opinions of others.
Tvad,

I'm probably more in the first camp in terms of how I set up my system, but the inherent flawed nature of many of the recorded musical performances that are my favorites forces me to be content in the second when needed. For example, I have no control over how many of the early Beatle's recordings in particular were produced. I have to accept the limitations of the sound because the music and performances are exceptional and make up for the lackluster sound.

I am happiest though with great music and performances that also happen to be well recorded so I can in fact practically exist in the first camp.

I am a music first guy. I will not not listen to something just because it sounds "recorded". I'd rather it sound more "lifelike" if it could, but it is what it is.
IMHO,holography expands the image.Omni's no not image therefore cannot be holographic.quoting from reviews, dictionaries or from the bible does not prove anything.
As Tvad stated,the enjoyment of what you are hearing is the only thing that is important
I think Tvad nailed it, there are two camps.

Mapman can go on and on about the advantages of whatever we're talking about, but he'll never convince those of us in Camp 1, me included, that what he's proposing is desired in our systems. Likewise, Camp 2 isn't going to like what I propose and it'll be found "lacking."

Dave
Tvad,
I certainly belong to the first group you have mentioned and although I enjoy music from whatever source and rig, I am after "the absolute sound" with an ear trained on live music from early childhood on. Hence what many here would call "good sound" for me is far from it, if I would listen critically to gear and not just to the music. After having had a chance to hear how Carver cleverly does his sound-shaping I found it artificial and euphonic, wouldn't have it. I'd probably have the same reaction with the H-Cat, because for me, these attempts destroy that what is real in spacial information in a good recording, where you can recognize the hall, with their induced artefacts. I don't like that, because I want go get as close to the real thing as possible. So if I am familiar with a hall, know how music sounds there from my favorite seat and I have recordings from the self same hall, am able to hear how the sound is reflected from the walls, can hear the side reflections and the back of the hall in the recording as the music spreads out in my room, there is indeed a sense of what one might call holography, because you can sense the body of the orchestra within the hall, can, if the score permits, even identify say the first violin, cello etc. If there is a soloist playing with the orchestra, his or her instrument can have its own holographic image, even bloom in the sense of air as I have tried to describe it.
I have, in my career as an audiophile. tried to enhance this by artificial means, but found that it destroys the "gestalt" of the original recording. There are of course many ways that lead to Rome, to the enjoyment of music in our home and luckily we are all free to find our particular ways to aural happiness.
Tbg,

Read the definition of holography and then listen to a pair of Ohms and then we can discuss whether or not it is holographic.
Mapman, omnis don't give holography but totally obscure where the music is coming from. There is no realism at all. If you make your definition of holography that you cannot find the location of the speakers, omnis are your choice. But certainly not the choice of those wanting realism of the recording venue or the sense of being there. You are right about Carver, however.
Actually, after reading the wiki definition of holography, it is probably a misnomer to call what the Carver circuit does "holography" because it only works when listening from on spot. You can't move around and get different perspectives.

based on this definition, I'd probably now asset that the only way you can get coherent holographic perspectives from a variety of listening locations, as is required by the definition, is with omni, pseudo-omni, or other very wide dispersion speaker designs that might be out there. Professional reviews of omni speaker designs always allude to this as one of the most unique aspects of these designs.

With their application of the highly phase coherent Walsh driver design, I suspect the Ohms and German Physiks are inherently capable of doing it best.
Dave,

I'm not necessarily advocating Carver holography, although I think the processing it does makes sense, it works as advertised, take it or leave it, and the benefits can far exceed the disadvantages. In fact, I no longer use the circuit because it is not required with my current set up.

The only speakers I've owned prior to the Ohm series 3's that I never found any value with using the Carver holography feature were the Triangle Titus monitors, which are so fast and detailed that the sound achieved a highly transparent, holographic effect on its own. Not true to the same extent with any other speaker I've owned including Dynaudio, Magnepan, and B&W or even original 80's vintage Ohm Walsh 2's.

Nothing that I've heard does holography as defined below (from wikipedia) as well as the Ohm series 3. You can move around the room and the perspective of the sonic image will change with you accordingly with little or no degradation.

Carver holography cannot do that. You have to listen from exactly the right spot otherwise the phase aspects you speak of come into play in a negative manner, not positive.

Let's face it that the whole concept of listening to music via a stereo system is in fact artificial and each system sounds different. All that matters is the end result and does it sound good to the listener.

I like the term "holographic" in describing audio though in the general sense that it captures multiple factors of good sound in a single term that describes what is needed to reproduce the complex live listening experience which is inherently 3 dimensional out of two boxes sitting in your room that inherently are not.

If a system does things well, there can be a holographic aspect to it that is a cumulative result of many other factors that we commonly discuss regarding good audio.

The end goal for everyone is this hobby I think is to make the reproduction of music in our rooms as real as possible. How can two little (or big) boxes capture what you hear live in 3-dimensions without the concept of "holography" coming into play?

A lot of things have to be going right for it to happen, and yes, there will always still be some things that do not go as "right" as others.

Below is the definition of holography from wikipedia. From this definition, how can holography be categorized as a bad thing when it comes to audio?

"Holography (from the Greek, όλος-hòlòs whole + γραφή-grafè writing, drawing) is a technique that allows the light scattered from an object to be recorded and later reconstructed so that it appears as if the object is in the same position relative to the recording medium as it was when recorded. The image changes as the position and orientation of the viewing system changes in exactly the same way as if the object were still present, thus making the recorded image (hologram) appear three dimensional. Holograms can also be made using other types of waves."
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Mapman, many of us associate holography with out-of-phase signals. Dark Side of the Moon and I Robot and Radiohead didn't get those huge images by accurately recording a performance in a real space. That's all done with signal manipulation. Carver does the same thing.

It can be very impressive to listen to, but it's not "real" except in the context that people like Alan Parsons meant it to sound that way. I love those recordings, but when I listen to the San Francisco Symphony play Mahler, I don't want it.

A system that adds it is performing a stunt, not unlike putting an effects pedal downstream from a guitar. Yes, it can be attractive, but is it the sound of the guitar, no.

Let's not confuse soundstage, bloom, depth, etc. with holography. One set of terms describes a real musical scene and the other describes an artificial effect.

Dave
Holography is a useful term for describing several attributes of good sound in audio together.

Carver's holography is an explicitly identifiable (analog) signal processing algorithm implemented in Carver equipment. When engaged, it improves the size of the sound stage and ones ability to identify specific players, instruments or recording elements within a more three dimensional sound stage. If you want things to sound more real, this is a good thing because these are attributes of a live musical performance as well that otherwise may often be lost with a 2 channel stereo audio playback system. It does in fact work very well when things are set up right and you listen from just the right place.

Carver is the only company that uses the term to describe a particular feature/function of their equipment that I know of, but I think the use of the term is the primary unique value.

Other equipment clearly achieves holography as well, through similar or different means perhaps, but they do not talk about much if at all, and the function cannot generally be switched in and out...its explicit in the standard operation of the equipment. Others more likely talk about the more commonly discussed elements of good sound that are typically present as well when holography is present, sound stage, imaging precision and detail, 3 dimensionality, bloom, etc.
Mapman,
Logic would dictate that the rendidion of "air" would depend on resolution and "transparency" and in fact, I think it does in the way these terms are generally used here.
This is not what I mean however, so I'll try again:
Strangely enough, the definitions you looked up describe exactly what I mean. It is a dynamic process which starts from a source and then spreads, flourishes... in case of music ...in space. This phenomenon strikes you at once, when listening to a live event right at the first bar of music in that split second before hall induced reverbs set in, as the sound emanating from the instruments rises and spreads. It is something airy as well as liquid, easy to pinpoint, hard to describe. Audiophiles, especially unfamiliar with big orchestral classical live music, probably have hardly heard this, because, as I said, our rigs cannot do this. Digital not at all, even if you mix in tons of hall, because that masks that effect, SS rarely and tubes sometimes. Most cone driven speakers - I am not familiar with more recent designs - mask this as well, stators and ribbons, also plasmas are better suited for this. As far as software is concerned, Blumlein miked , Decca trees, or the Mohr, Layton recording techniques did bring something of this across. I had Quads and Jadis gear at this time. It was, though euphonic, closer to the real thing than most of the rigs I have occasion to listen to now. But then of course my ears have grown old and I have resigned to the fact, that with things being as they are, you will hardly get those very special magical enthrallments at home. There are plenty of others though, to draw us deeply into the enjoyment of our rigs.

Clio,
Are you suggesting, that we use mushroom-paste based filters in our gear? Where would you say can those be implemented? ÃŽn the ICs or the speaker cables? At the source or the receiving end? Please enlighten and I'll get in touch with retail at Los Tres Rios and will talk to Jack Bybee to go into a joint venture.
Does holography (I can't believe I just said that) come at a cost? That is, does a system designed for maximum spatial attibutes suffer, generally, in some other area of performance - like timbral accuracy? Is H mutually exclusive with some other area of performance?
For me the use of psilocybin always increases my sonic holography taking it way beyond 3D.
"The more transparency you get, where SS excels, the less air seems to be possible around the instruments. "

This is not consistent with my experience. I find "air" is more associated with transparency. It can happen with SS or tubes.

Regarding bloom, this term confounds me personally.

I have looked the term "bloom" up and cannot find a definition that pertains specifically to sound or audio.

I found this:

2. To shine; glow.
3. To grow or flourish with youth and vigor.
4. To appear or expand suddenly: White vapor bloomed from the side of the rocket's fuel tank.
v.tr.
1. To cause to flourish.

Make the emotional association of this with the sound you like as you will.

I suppose my system flourishes with vigor, so maybe its bloomier than I thought prior. Definitely holographic though...
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To me bloom is the same as harmonic richness. Bloom is not fat or warm per se. It is a highly complex (due to overtones) sound with texture. "Air" is the surrounding and expanding sound we generally don't hear in real life. I think air is an artifact of microphones. "Air" is not: ambient clues --> the diffuse reflected sound by hall acoustics and nearby structures. "Air" that appears like an "aura" is totally wrong! We don't hear such a thing in real life. You can hear this "aura" like phenomenon with the older Jadis units for example. Like Dave said: it is pretty but not very realistic (although some people are addicted to this "aura").

Chris
I think that bloom is a natural event that occurs in real, acoustic music. Some might call it "air" but to me it's the overtones and ambiance of a live music scene or event. So a trumpet player plays a ringing high C, there's a "brrr" of the bell that's the overtones adding the trumpets characteristic edge to the sound and that's all mixed with the room reflections and other instruments.

Atmasphere seems to have chosen to define bloom as an artificial event, distortion. I think that bloom is just like frequency response, it can be accurate or not. Added bloom is unnatural and to be avoided, just like a hump in the frequency response at 60 hz is to be avoided. Both are inaccurate and both types of distortion can be euphonically pleasant in certain contexts.

As I've said before, IME, the best SS and tube components have very accurate imaging and get bloom and frequency response right. Some lesser equipment adds bloom and holography to get peoples attention, but it's not good in the long run for most of us. At the top of the heap, both tube and SS are very good in all these respects.

Dave
Ralph,
in reading you post I suspect that I probably have used the expression "bloom" wrongly. I thought bloom would be the air you hear around instruments in real life. Possibly "air" would have been the better word instead of bloom, although the sound blooms, spreads in an aura around the instrument that is played. This I find is most difficult to reproduce. The more transparency you get, where SS exells, the less air seems to be possible around the instruments. Digital, no matter how good it has become,is still disappointing as far as airiness is concerned. Harmonic distortion in tubes can mimic air to a certain degree. The first time I heard this, was with the old Jadis gear. It was pleasant but highly euphonic. Your gear has some air, but it seems to be neutral to my ear. Manley ( the son ) also seems to have had some measure of success in this field, as has the Wavac phono, which I have heard. However all these efforts are still far from real life and to my mind, this constitutes the biggest gap between the live event and our facsimilies. If I understand you right, "bloom" according to your definition would then always be the result of even order harmonic distortion in tubes. It sometimes mimics air to a certain degree, but it is basically something different.
Guys, for questions and user experiences with the H-Cat line stage I would merely direct you to the h-cat.com website. As Mr. Fiel suggests, I am enthusiastic about the H-Cat sound. I do not sell this equipment, while Mr. Fiel does sell rival equipment, but I have had 47 years of experience with audio equipment. Of course, your experience may differ from mine, but for many around the world have validated my experience with this product.
In my experience, there's very little difference in the holographic abilities of tubes vs. SS. Listen for yourself and decide for yourself without regard to one technology vs. the other. Listen for the overall presentation, with your speakers, preferable in your room. When you find well designed equipment the differences will melt away.

Dave
Mapman, my experience has been that anywhere you can involve tubes in audio will help, as long as the tubes are in a competent circuit :)
Atmasphere,

My system is currently highly transparent and holographic, I would say.

But I've thought about trying a tube pre-amp with my SS amp to get more of the sound of tube harmonics going, which I tend to like as well when I hear a good tube-amp'ed system.

Do you think a hybrid approach like this is likely to result in a more compromised, middle of the road sound, or could it add a touch of tube-like harmonics in a manner that benefits without negatively impacting the good things already happening?

Tube power amps will not work well with my Ohm speakers I am convinced due to their low efficiency and somewhat difficult load, so that is not an option for me.
By the way, on eother negative about Carver holography, for those interested, is that you have to have the speakers set up just right and listen from just the right position to hear it.

One of the reason I went with Ohm speakers is that I hated that aspect of the Carver holography to achieve the desired effect. With the Ohms, you get equally good holographic imaging as I described above from a wide range of listening locations in the room. I do not think this is possible in general with highly directional speakers (I've never experienced it) but I could be wrong.
Having worked with a good number of master tapes, I might be able to help with the terms here.

Bloom: a function of harmonic distortion, part of a spectrum: neutral, warmth, bloom, thick or fat, bloated, muddy all describe distortion, usually lacking odd orders, so it is more of a coloration than an irritant (generally associated but with not limited to tubes). Odd-ordered colorations are harsh, chalky, clinical, bright, etc (generally associated with but not limited to transistors).

Thus an amp that is transparent will lack bloom (although it can sound natural), as transparency comes from a lack of distortion.

Holographic imaging is a function of soundstage. It comes from the ability to reproduce low level detail and maintaining phase relationships, so it requires wide bandwidth for the latter and low distortion at low levels for the former.

Transistors have traditionally had difficulty with retrieving low level detail, and so the slight ambient cues that exist around an individual image in a soundstage are less likely to get reproduced. This will give the image a 2D quality in the soundfield, and simultaneously cause it to stand out more. Newbee correctly identified this phenomena, although I would like to add that as the slight ambient cues that exist around each image get added, there will be the effect of a more 3D image, but also a more homogenous overall effect in the soundstage as the relative size of the 3D image will be larger than that of the 2D image of the same thing.

Tubes are better at doing low level detail, and so are more likely to have 3D images and greater ambient information, adding to the holographic effect. Any processing in the signal chain that is not part of the original recording can be regarded as a form of distortion, as most imaging systems rely on altering phase relationships to obtain 'holographic' effects. Tubes are not so great at keeping phase relationships correct, as often tube amps have less high frequency bandwidth, owing to the presence of an output transformer, but there are nowadays amps with wide bandwidth OPTs and of course OTLs :) that overcome this issue.

If phase issues exists at or very near the upper limits of human hearing, some interesting imaging effects can occur that seem to enhance the 'holographic' effect and I would not doubt that this has served as an inspiration to some processor designers! At any rate this accounts for why some tube amplifiers that are not great performers in the bandwidth department can have some apparently 'enhanced' imaging effects.

If there are no phase anomalies and low level detail is maintained, many 2-mic recordings will exhibit a height phenomena, which is a function of the mic placement in the soundfield.

Having master tapes so you **know** what the recording is supposed to be like is paramount to sorting this stuff out!

Sorry for the diatribe...
Actually, I just read about the H-CAT approach.

Seems like it requires careful "tuning" to provide the advertised benefit and that some have achieved "it" and some achieved something perhaps less desirable otherwise.

Definitely a different approach than Carver sonic holography, which the site correctly alludes to.

Having heard that the Carver holography does in fact work, I'll keep an open mind regarding this approach. Sounds like a different approach to lowering amp distortion than typical negative feedback approach as I understand it.

The site left the impression that earlier versions did not provide adjustment of the correction which is absolutely needed otherwise the chance of the gadget working was low. Assuming true, it was not very smart of the vendor to sell a gadget to audiphiles as such (missing a primary feature needed to work in most cases).

The Carver approach was technically not that complicated, yet effective. This approach seems much more complex and harder to get right, assuming it does in fact work. I suppose the only way to know would be to try it.

Does the vendor offer any kind of money back guarantee? I would think that might help entice those interested in taking the plunge.

Were I to go to a different SS pre today in search of better sound (rather than tube), I would strongly consider Classe based on what I have actually auditioned and liked.

How many owners and why not more?

Only a couple posting here; one being a pom pom waving cheerleader.

With products in this hobby, performance and sales are very closely associated in most cases IMO. One might surmise the reports we read here are, for whatever reason(s) embellished to some extent. Owners have an inherent bias with a financial investment. Afterall, how many audiophiles after just dropping $5K or $10K have the stones to say "This thing really sucks; I've been hosed".

Very few indeed.

On the upside you can use the doppler thingamajig to forecast weather.
I've been considering a tube pre as well but would prefer to stick to SS as well.

What does H-CAT do that other SS pre-amps do not that makes it unique?
How many folks out there own the H-CAT? I've never heard it, but if it is half as good as Tbg says it is I'm surprised there would not be more owners. I would love to have an SS pre that puts my tubes pres to shame, in every way.