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Stereophile's Jim Austin disagrees w Atkinson; says tubes have something that can't be measured

Spocko

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Fully agree.
I do wonder sometimes whether some of the complex and subtle harmonics of acoustic instruments are not picked up to their full extend during a recording, or are not fully reproduced by the listener's speakers. In such cases, adding similar harmonics artificially during playback may result in s sound that is more akin to hearing a live acoustic instrument. I use a sonic exciter in my signal path, and the harmonics it adds - if used in moderation - do seem to make voices and acoustic instruments more 'lively'.
You bring up a different point, and you may be on to something but I honestly believe that the acoustic harmonics missing would likely be lost due to the speakers or recording rather than anything else. But now we're into the realm of the unknown as to what can and cannot be recorded. Then we have to determine whether the signal altered by tubes' harmonic distortion has a greater affect than the missing harmonics being introduced.

Also, consider this: listening to the absolute best stereo system (let's say you have $800,000 to put one together) playing the most competently recorded jazz ensemble in a perfect recording studio will sound nothing like what you would hear sitting in that very same recording studio listening while the band was being recorded. These are two very different experiences, each with their unique sound. The point was not to recreate what you heard in the studio but play what was engineered/mixed on the digital recording as "the mixing engineer intended" for you to hear. With this distinction in mind, it may not matter that that you've lost some harmonics because there's a whole lot of other information being changed/lost during the production!
 

MattHooper

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It was an off-target implication that, to the individual listener, those two alternatives are indistinguishable.

Ok, off-target replies have a habit of ...not landing on the right target. A bit like walking in to a party and announcing "SOME people here are full of sh*t." That has people likely beyond the target wondering who exactly that was meant for. :). So I guess you were gesturing at the audiophile who might purchase such a device.

Of course the alternatives batted around on those "tube knob controls" - imagination vs real audible difference - aren't distinguishable, strictly speaking, if we are talking only about regular sighted listening evaluations, and applying scientific standards.

But also, obviously this applies to one degree or another to ALL our sighted listening experiences. Which would included your reviews of speakers as I'm sure you'll agree.
Could just be sighted bias. But, that the speakers you review do sound different is highly plausible, so even though you have no access to the measurements before writing the review, you feel the sonic impressions are warranted. And I agree.

In the case of Gilbert's preamp the difference in dialing the knob way up or down seemed absolutely distinct to all three of us. Could it be, like a speaker review or anything else, just a sighted bias effect? Sure! Strictly speaking. But...is it plausible that the designer can screw with the sound via a knob on a preamp, via changing the circuit in various ways (capacitors etc)? As far as I know, that's entirely plausible. I don't think this is exactly the technical equivalent to, say, ultra expensive ethernet cables in that regard.

Put together, I think given the apparent obviousness of the sonic change we all felt we heard, with the technical plausibility Gilbert could have audibly screwed with the sound for that "tube" knob....I think I'm justified in tentatively concluding we heard those differences. I could be wrong of course...but that doesn't mean a conclusion with that caveat isn't justified.
 

Spocko

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From my perspective on the production side, this is his argument's own goal. What is this less tangible thing that is retained? He would say soul, emotion, euphoria, engagement, whatever. I would confirm: so that's all in the file, but it's in danger of being stripped away, so it needs to be consciously retained? He would agree. I would ask him - how did it get in the file in the first place? Immediately after the microphone diaphragm everything goes through cold, hard, sterile solid state, and, even worse, digital. If we put it in that way, why can't we get it out the same way?
Aaaah so we get to the "circle of confusion" that Dr. Toole has warned us about - the recording engineer and production team, choice of microphones, microphone placement, room reverb, added digital reverb in post-production, etc. That all has a HUGE effect on capturing the sound; then you have the mixing engineer whose personal listening preferences come into play - he can choose to make the drums more prominent, compress the vocals a bit more, reduce the high hat a touch, etc. At best, your hifi system is replaying the producer's unique vision (he may even be correcting for bad mic placement!) but it is NOT replaying what was heard in the studio if you actually sat there. The fact that studios use $9,000 tube microphone plus compression to warm up a singer's voice for recording says all we need to know.
 

Inner Space

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Aaaah so we get to the "circle of confusion" that Dr. Toole has warned us about - the recording engineer and production team, choice of microphones, microphone placement, room reverb, added digital reverb in post-production, etc. That all has a HUGE effect on capturing the sound; then you have the mixing engineer whose personal listening preferences come into play - he can choose to make the drums more prominent, compress the vocals a bit more, reduce the high hat a touch, etc. At best, your hifi system is replaying the producer's unique vision (he may even be correcting for bad mic placement!) but it is NOT replaying what was heard in the studio if you actually sat there. The fact that studios use $9,000 tube microphone plus compression to warm up a singer's voice for recording says all we need to know.
No, nothing to do with circles of confusion - merely a question: why does JA2 need tubes downstream of the file, to "retain" stuff that was put there by solid state equipment and software simulations?
 

Kal Rubinson

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But also, obviously this applies to one degree or another to ALL our sighted listening experiences. Which would included your reviews of speakers as I'm sure you'll agree. Could just be sighted bias.
Agreed.
But, that the speakers you review do sound different is highly plausible, so even though you have no access to the measurements before writing the review, you feel the sonic impressions are warranted.
Yes but I will admit that, if I have my own doubts, I will do some of my own measurements.
 

Ken Tajalli

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This being ASR, the answer would be obvious - examining what if anything was done with the circuits of those knobs, measurements, blind test - so I presume you were channeling Jim Austin there? :)
If the knobs were just using resistors and caps, then its obvious.
A simple or complex FR shaping.
that's all. Such circuits can not generate distortions etc.
 

MattHooper

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No, nothing to do with circles of confusion - merely a question: why does JA2 need tubes downstream of the file, to "retain" stuff that was put there by solid state equipment and software simulations?

Perfect!

That's what I'm always pointing out to audiophiles who feel their systems require expensive cables in order to deliver all the sonic information from the source. They are usually listening to music created with bog-standard pro audio cables. Which means every iota of detail they believe they are hearing with their fancy cables was transmitted perfectly fine via the cheap cables used to make the recording. I've yet to see a cogent answer to that conundrum.

I have no problem if particular tube amps are sold as some level of distortion generators (to the degree it's audible). But often enough they are sold as removing the distortions that come with solid state designs, "getting a more pure signal, moving you closer to the music." In years and years of tube amp measurements on Stereophile or anywhere else, I've yet to see this justified. Which if course is what lands Jim in his current position.

(Of course Jim may also be saying that he's referring to a certain intangible, yet to be measured "something" that is added by tube amps. But as everyone here would point out, this fails to distinguish that position much from pseudo-science or any number of faith-like belief systems).
 

mhardy6647

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well, of course!
Vaccum tube have je ne sais quoi.

Some have far more than others.
Little 7-pin miniature power pentodes used for single-ended audio output in 1960s US color TVs -- not so much.
Direct heated power triodes like the 2A3, 300B, 45, or 50 are drippin' with it.

;):cool:
 

SIY

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I know this is your hobby horse but it still doesn't make sense.
Spend more time designing, building, measuring and listening to them and it will make more sense.
 

Omar Cumming

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This is the IMD measurement of the $10K 10 watt amp that J Austin rhapsodizes about

523-Mas845fig11-600.jpg

All I can say is Good Grief!

Cheers
 

amirm

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Instead of worrying about imagined effects that can't be measured, let's talk about what is measured: distortion. I hear it all the time in these boutique amplifiers and it is anything but pleasant. At low levels it is barely there but as you crank up the level/distortion, the sound gets muddier and muddier. Highs get shrill. And overall sound goes to hell. The question for Austin is: why don't his subjective reviewers and their readers don't hear these impairments? Answer is simple: they don't have critical listening abilities to not hear what is plainly and provably there as unwanted aberrations.

Another point: if these distortions and high impedance causing frequency response variations, why don't company advertise them? Answer is that in many cases these are not measured by the designers so a bunch of it is unintended consequences of not verifying designs. Take power supply noise. What positive attribute does it have? How about hiss and hum? Shouldn't these be kept to absolute minimum if the goal is "like live music?" I mean look at this:

index.php


We have no trouble measuring those spikes outside of harmonic distortions. Does Austin have an explanation for why his reviewers like those? Again, these are facts that we can have measured that cannot be disputed. Let's get an explanation of these before jumping into the unknown.
 

Somafunk

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why don't his subjective reviewers and their readers don't hear these impairments?

Answer is simple: They wish to be admitted to the audiophile club and bask in the dopamine release that comes with affirmation from the false gods/gurus who review such items.
 

fpitas

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well, of course!
Vaccum tube have je ne sais quoi.

Some have far more than others.
Little 7-pin miniature power pentodes used for single-ended audio output in 1960s US color TVs -- not so much.
Direct heated power triodes like the 2A3, 300B, 45, or 50 are drippin' with it.

;):cool:
Of course, the little bitty TV pentodes had a little bitty cheap-as-dirt output transformer that barely did the voice range.
 

theREALdotnet

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Regarding distortion, which is a non linear phenomenon, the plot thickens a lot.

Well, harmonic distortion is non-linear. But it seems that linear distortion is one of the Achilles heels of those feedback-less tube amps and their grotesquely low damping factors. Their frequency response can be a bumpy ride, depending on the speaker.
 

MattHooper

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Spend more time designing, building, measuring and listening to them and it will make more sense.

That's a non-response to the problems I posed to your claim. Your technical experience doesn't entail that all the arguments you make are sound. For reasons I've given, you seem to be aiming at a straw man, one where "tube sound" is discussed without any distinctions whatsoever.

Many people who design, build, measure and listen to tube amps (not just manufacturers) would agree with what I wrote - that tube amps *can* sound different from solid state (whereas it would be more rare for those distortions to be audible between solid state amps). So it's relevant to have a category of "tube sound" where specific characteristics can be discussed.

There is nothing about having a "tube amp" category that means it can't be measured, since tube amps CAN measure differently, sometimes audibly so. The only way to cling to your position, it seems to me, is to do some sort of tautology like "I'm referring to the category of tube amps that don't measure or sound different from each other or from solid state - therefore there is no Real Tube Sound."

(And as it happens, as detailed in the forum I blind tested my tube preamp against my solid state preamp and did indeed seem to reliably detect characteristics I had formerly described as "tube vs solid state" sound in my system - some of which were similar to the effect of the "tube knob" on the preamp discussed here - so I certainly find the distinction useful).
 
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mhardy6647

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Of course, the little bitty TV pentodes had a little bitty cheap-as-dirt output transformer that barely did the voice range.
Well -- there is that.
But I'm tellin' you -- it' s je ne sais quoi. ;)
 

SIY

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That's a non-response to the problems I posed to your claim. Your technical experience doesn't entail that all the arguments you make are sound. For reasons I've given, you seem to be aiming at a straw man, one where "tube sound" is discussed without any distinctions whatsoever.

Many people who design, build, measure and listen to tube amps (not just manufacturers) would agree with what I wrote - that tube amps *can* sound different from solid state (whereas it would be more rare for those distortions to be audible between solid state amps). So it's relevant to have a category of "tube sound" where specific characteristics can be discussed.

There is nothing about having a "tube amp" category that means it can't be measured, since tube amps CAN measure differently, sometimes audibly so. The only way to cling to your position, it seems to me, is to do some sort of tautology like "I'm referring to the category of tube amps that don't measure or sound different from each other or from solid state - therefore there is no Real Tube Sound."

.
I can't categorize made-up concepts. Tube amps have widely divergent distortion levels and profiles, widely divergent source impedances, widely divergent overload and recovery behavior.
 

DonH56

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In blind tests I doubt anyone could tell a competent tube preamp from a SS preamp. For power amps, it very much depends upon the load (speaker) and output transformer (or just output impedance of the amp). A tube as a device is not intrinsically higher in distortion than a transistor; in fact, the opposite is true. "Tube sound" is a product of design choices rather than the device, and there are many tube amplifiers designed to exhibit very low distortion. And you can build a SS amp that sounds like a tube amp, of course. I think much of the confusion is because there is a very wide range of tube amps with wildly varying performance whereas most SS amps have similar performance, and marketing plays into the customer base for a tube amp.
 
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