Tubes in Hi-End Preamps

Newbee, yes I picked the example because, in my experience, both are clearly audible, but which would be more audibly neutral? For me, there is the rub. The former, while an order of magnatude greater, is related to the signal, the latter is not. You said that the former is more neutral, to you, but doesn't that imply that neutrality is a subjective judgement? My definition of neutrality would make it an objective quality with both examples equally failing to be neutral. I think that is what makes the concept of audible neutrality a fiction to me.

Viridian,

What I said was that 2d order harmonics sound more 'natural' to me. I parenthesized 'neutral'with a ? mark only to emphasize that I didn't think the my use of the term natural necessarily encompassed neutrality, but some might think these terms were identical in this context. That is, to be natural demands neutrality.

If I may digress a bit - I think many, myself included, are convinced that the best result in home audio is brought about by a careful matching of the speakers to room acoustics, the amps to the electrical requirements of the speakers, the pre-amps to the needs of the amps and sources, and lastly the sources to please the ears of the listeners.

None of these components need to be neutral to succeed in their function, in fact bending of the tonal balance by selection of certain components is often what makes a meaningful difference to the user because they need to compensate for other tonal imbalances brought about by compromises in the choice of room, speakers, amps, etc. They should all be highly resolving as pratical but tonally accurate (read neutral) is, for me at least, not necessary.

Some bend the tone with cable, IC's, tubes, PC's and even tweeks. But bend the tone they do and in the final analysis they have the tone that they feel is most natural, not which is not necessarily more neutral.

On a purist level, I will be very impressed when some one can prove to me, not just speculate, that they have been successful in actually replicating, or even coming close for that matter, to the sound that was recorded on the source. For those who might, I might ask if they were present when the recording was made and why they have such confidence in their long term aural memory.

Being a 'hair shirt' audiophile is no walk in the park! :-)

Newbee, yours is as cogent an illumination of our constant tweaking and upgrading as I have ever read. I would not hold my breath waiting for someone to come forward with any "proof" of accuracy.

This is an interesting thread. But has anyone yet answered the question, "What's the point then of having tubes?"

I won't talk much about neutrality and/or transparency or the issues of distortion, etc., as much of this can be rather subjective. But what tubes do for me is simply recreate the portrayal of space, the harmonic textures and decays. It's been a few years since I have heard some solid-state-based "audiophile" systems, and these were not even close to much lower cost tube based systems in the context of these sonic attributes. I have to believe this is inherent with solid state devices.

I have done a lot of experimenting with Mullard and Telefunken 12ax7 and 6DJ8/6922 tubes in Aesthetix Io and Callisto models. When these models started with Sovtek tubes, and immediately changed to a mixture of Tele/Mullard, the overall character of the sound was very similar. I can relate to what Mechans says about his highly modified SP6B. But what the tube changes did was take these models from a very good level to a stellar level. For $1000 or so, I made improvements here that would have cost 10x as much on a similar scale with solid state designs.....and still, the SS design would not come close to the attributes noted. SS diehards would claim I added all sorts of distortions to the system. But when I go upstairs and hit a piano key, the end result indicates to me something is very "right" with the change.

The nice thing about tubes is tuning a system to one's preferences. I do not think of this as synergy as this implies a perfect match. Rather, it is all about achieving a balance of many sonic attributes most important to each of us.

If I want more energy and dynamics on the top with a 6922 tube, I choose the Mullard. But the side-effect is a fatter midrange. A change to the Tele and I have greater tonal coherency, a little less life on the top but more extended low-end. Which is more accurate or neutral or transparent? Who knows as I am judging the result based on the rest of the system which is also loaded with tubes. And the same with the 12ax7. The Tele 12ax7 brings out magical bloom in the Io but with the Callisto, for me anyway, the Mullard 12ax7 brings on an authoritative and dynamic presentation that is wonderful.

I can put all these tubes in a CAT Ultimate preamp's line and phono stages and hear these same differences between tube brands. The fundamental sonic signature and strengths/weaknesses of each preamp design carries on as I change from one tube brand to the other. I simply get greater refinements and a little more emphasis in one direction (dynamics/warmth) or another (coherency) when I try these differening tube models. This is something I can not do with a SS product nor a product that uses the 6H30 "super" tube.

The key for me has been to find a product (in stock form) that really caught my attention. The CAT and Aesthetix models are about as different as any two I have heard and I owned ARC and BAT preamps for a combined 17 years until going with Aesthetix. Choose the model that feels right and then play with tubes to perhaps bring out a little more magic or alter the tonality to your own liking. This to me is the point of owning tube gear.

John

Here's an answer for the tube question:

Our ears have evolved a certain way over literally millions of years. We cannot change that. Tubes and transistors have distortions that are unique to those devices. It just so happens that tubes have distortions that are innocuous to the human ear, IOW they more closely observe the rules that the ear has evolved to. Transistors are less observant of those same rules and so while they have less *measurable* distortion, the distortions that they do have are far more irritating and audible than those of tubes.

In short, if we can reduce the distortions that tubes have then we will be really getting somewhere. Fortunately that is happening in the world of high end audio.