Why haven't subjectivists and objectivists met to do a live ABX test?

[rsoffer]

I absolutely do NOT agree. Nor is there any evidence to back up the contention.

Which part don't you agree with? That tube amps sound audibly different? Or that both camps agree that tube amps can be nice?

 

[SIY]

Which part don't you agree with? That tube amps sound audibly different?

"audible differences that are appreciable" There's just no evidence for that. None. And I say that as someone who has designed, built, and used a LOT of tube gear.

 

[rsoffer]

"audible differences that are appreciable" There's just no evidence for that. None. And I say that as someone who has designed, built, and used a LOT of tube gear.

I'm confused. You're saying all that added distortion from the tube amps has no audible differences? In theory tubes have no limit to how much distortion they can add to the signal. How would that not make an audible difference?

Edit: or are you saying the differences aren't positive? Which is really just subjective in nature, not sure what evidence could back that up. If someone prefers distortion, how can you argue lol

 

[SIY]

I'm confused. You're saying all that added distortion from the tube amps has no audible differences?

Humans are not nearly as sensitive to distortion as audiophiles would like to believe.

In theory tubes have no limit to how much distortion they can add to the signal.

Nor do transistors.

Again, no-one has ever proffered evidence of this "warm" sound. And back in the era when Stereophile had some credibility, Gordon Holt claimed that tube amps were brighter and more forward than solid state, which seems like the opposite of more contemporary evidence-free claims of "warmth."

 

[ahofer]

Humans are not nearly as sensitive to distortion as audiophiles would like to believe.

indeed. @rsoffer can test himself here: https://www.klippel.de/listeningtest/

 

[rsoffer]

Humans are not nearly as sensitive to distortion as audiophiles would like to believe.

Nor do transistors.

Again, no-one has ever proffered evidence of this "warm" sound. And back in the era when Stereophile had some credibility, Gordon Holt claimed that tube amps were brighter and more forward than solid state, which seems like the opposite of more contemporary evidence-free claims of "warmth."

I see what you mean. It's probably still very difficult to tell the differences with normal music under normal conditions. I guess I'm going off what amir posts as "audibly transparent" - which many tube amps don't reach.

I guess everything probably sounds basically the same lol.

 

[solderdude]

I guess everything probably sounds basically the same lol.

Tube amps often do not but not because of harmonic distortion in general.
With harmonic distortion also comes intermodulation distortion when more than 1 frequency is present.
Tube fans don't really want to know as they prefer to look at a 1kHz sinewave spectrum and are in awe about the harmonics and how dominant the 2nd one is.
This is supposed to be the good one and the odd ones are bad. Balanced tube amps have mostly odd order distortion but still are marvelous.
Just look at multitones with tube amps and you will see a bunch of grass that does not belong.

As SIY already mentioned... you should not blame harmonics for the 'warmth' but this is usually caused by the high output resistance combined with varying speaker impedances.

That said, yes some (better designed) tube amps will be indistinguishable in a well performed blind test, some will certainly sound different.
The weird part is... tubes always seem to 'sound better'.

 

[Spkrdctr]

Is it a bad thing to say I have never owned a tube amp or listened to one?

 

[rsoffer]

Tube amps often do not but not because of harmonic distortion in general.
With harmonic distortion also comes intermodulation distortion when more than 1 frequency is present.
Tube fans don't really want to know as they prefer to look at a 1kHz sinewave spectrum and are in awe about the harmonics and how dominant the 2nd one is.
This is supposed to be the good one and the odd ones are bad. Balanced tube amps have mostly odd order distortion but still are marvelous.
Just look at multitones with tube amps and you will see a bunch of grass that does not belong.

As SIY already mentioned... you should not blame harmonics for the 'warmth' but this is usually caused by the high output resistance combined with varying speaker impedances.

That said, yes some (better designed) tube amps will be indistinguishable in a well performed blind test, some will certainly sound different.
The weird part is... tubes always seem to 'sound better'.

I suppose this was my overall point. They are often distinguishable. Whether this is preferred on an individual basis is irrelevant.

 

[solderdude]

I suppose this was my overall point. They are often distinguishable. Whether this is preferred on an individual basis is irrelevant.

But is it because of tubes, distortion profile or other aspects and when they are distinguishable in a proper and controlled blind test how different do they measure (on actual loads).

 

[SIY]

I suppose this was my overall point. They are often distinguishable. Whether this is preferred on an individual basis is irrelevant.

Frequency response is the issue due to the interaction with the speakers’ impedance. But that’s just EQ, it varies from speaker to speaker, and a solid state amp with a high source impedance will have exactly the same effect.

None of that has anything whatsoever to do with “warmth.” And given the lack of any positive results in controlled listening tests, merely repeated anecdotes and claims, it’s most likely that this is a psychological issue- tubes are warm so they give a warm sound.

 

[Blumlein 88]

Frequency response is the issue due to the interaction with the speakers’ impedance. But that’s just EQ, it varies from speaker to speaker, and a solid state amp with a high source impedance will have exactly the same effect.

None of that has anything whatsoever to do with “warmth.” And given the lack of any positive results in controlled listening tests, merely repeated anecdotes and claims, it’s most likely that this is a psychological issue- tubes are warm so they give a warm sound.

C-J gear in warm gold tone was warmer than Audio Research gear in their silver livery. Or so the consensus was at one time.

 

[Newman]

I suppose this was my overall point. They are often distinguishable. Whether this is preferred on an individual basis is irrelevant.

What do you mean, “often distinguishable”? Are you talking about sighted listening test comparisons?

Because valid controlled listening tests of valve vs transistor amps are exceedingly rare. Words like ‘often’ don’t apply. And IIRC they seem to conclude that a well designed valve amp with sufficient feedback is not distinguishable.

I get the impression that you are referring to valve amps that are so heroically misconceived that they lack damping to such an extent that it audibly affects their sound via typical speakers? In this case, I vaguely recall a controlled listening test where they added a power resistor to the outputs of a solid state amp and suddenly it was indistinguishable again. It might have been Carver.

cheers

 

[fpitas]

What do you mean, “often distinguishable”? Are you talking about sighted listening test comparisons?

Because valid controlled listening tests of valve vs transistor amps are exceedingly rare. Words like ‘often’ don’t apply. And IIRC they seem to conclude that a well designed valve amp with sufficient feedback is not distinguishable.

I get the impression that you are referring to valve amps so heroically misconceived that they lack damping to such an extent that it audibly affects their sound via typical speakers? In this case, I vaguely recall a controlled listening test where they added a power resistor to a solid state amp and suddenly it was indistinguishable again. It might have been Carver.

cheers

Yeah, I think that was one of his tricks.

 

[Axo1989]

If I'm being honest, I'm not sure what I'd think. It would be very interesting to discover some new, verifiable measure of audio quality that I could maximize in my system. On the other hand, the current progress in amplifiers (where a purifi amp gives you far more progress on known dimensions than you could ever dream of at the price 30 years ago) is also exciting. Discovery of some actual, audible advantage to the Krell/D'agostino/etc. expensive methods would be a bummer for my wallet and physical comfort. I was pretty happy to rid myself of my Nelson Pass space heater.

Your cat didn't like the toasty warmth in winter—or were the heatsinks uncomfortable? Mine loved lounging on my old Krell. They filled it with fur though and I had to get it fixed.

We have D'Agostino's latest at Stereophile just now. Certainly the harmonic distortion is relatively high (he no longer designs to measurements like in the Krell days, he reckons). Based on that AB test we did here in @GXAlan's thread a while back it may or may not be audible though. But the THD+N vs output power is the smoothest of curves. No knobbly knees or sharp elbows as we approach maximum power. If I had $80K burning a hole in my pocket and a taste for steampunk (I don't, but de gustibus non est disputandum) I'd like that.

Spoiler: Smooth.

 

[fpitas]

The D'Agostino's output impedance was 0.5 ohm at 20Hz and 1kHz, increasing slightly to 0.55 ohm at 20kHz.

Uhm...

 

[fpitas]

Your cat didn't like the toasty warmth in winter—or were the heatsinks uncomfortable? Mine loved lounging on my old Krell. They filled it with fur though and I had to get it fixed.

We have D'Agostino's latest at Stereophile just now. Certainly the harmonic distortion is relatively high (he no longer designs to measurements like in the Krell days, he reckons). Based on that AB test we did here in @GXAlan's thread a while back it may or may not be audible though. But the THD+N vs output power is the smoothest of curves. No knobbly knees or sharp elbows as we approach maximum power. If I had $80K burning a hole in my pocket and a taste for steampunk (I don't, but de gustibus non est disputandum) I'd like that.

Spoiler: Smooth.

View attachment 291032

It *might* be worth a couple thousand, tops. I have no idea why it costs $80k, except bragging rights.

 

[Axo1989]

The D'Agostino's output impedance was 0.5 ohm at 20Hz and 1kHz, increasing slightly to 0.55 ohm at 20kHz.

Uhm...

Compare to 0.05 Ω on a Krell Evolution series. No one said you couldn't get 'tube sound' using solid state. Probably his intention.

Spoiler: they aren't called Krell anymore, there's more than one reason for that.

It *might* be worth a couple thousand, tops. I have no idea why it costs $80k, except bragging rights.

Veblen goods. You understand economics and consumer preference, yes? What you or I would pay has no bearing on anything there.

 

[fpitas]

Compare to 0.05 Ω on a Krell Evolution series. No one said you couldn't get 'tube sound' using solid state. Probably his intention.

Spoiler: they aren't called Krell anymore, there's more than one reason for that.

View attachment 291035
View attachment 291036

Veblen goods. You understand economics and consumer preference, yes? What you or I would pay has no bearing on anything there.

That's true.

 

[Mart68]

It *might* be worth a couple thousand, tops. I have no idea why it costs $80k, except bragging rights.

have you seen one in so-called 'real life'? The case alone must cost them several thousand dollars to have made. Then multiply that cost by 20 to get the sale price.

I mean the build quality is heroic. That's never going to sell for buttons and make money, especially as it's a low volume product.

prefer the look of the old Krell kit myself which you can now get fairly cheap s/h thanks to Class D taking over the market. And it's exactly the same as the new D'Augustino in practical sound quality terms and measures better too.