Do Tubes Homogenize the Sound of Our Music?

[charles1dad]

No, it is the fault of that specific example...

Yes indeed! This is a more correct explanation.
Charles

 

[Atmasphere]

No, it is the fault of that specific example...

Really? Its well-known that the prodigious 2nd harmonic (which all SETs have unless they use feedback, which most don't) imparts 'warmth'; a euphonic coloration. That fact has been known since the 1930s and isn't controversial.

I am wondering if the question of the OP is really just about distortion. You could ask the same question of most solid state amps, which impart 'harsh and bright' due to the unmasked higher ordered harmonics they tend to exhibit.

Between the two I prefer the 2nd harmonic- its much more innocuous. But usually comes at the cost of high output impedance, meaning that the amp that has it has to be very carefully matched to the load (with SETs and also our OTLs, this means higher impedances and easier to drive speakers are preferred).

 

[Cellcbern]

"Homogenization" or not (I've never heard any in my tube based systems), - tube amplified systems seem to dominate audio show "best of" selections year after year, e.g.:

The Capital Audiofest 2022 Fab Five My selection of the Top Five best sounds of CAF 2022. Capital Audiofest 2022 Show Report By Greg Weaver Of Enjoy the Music.com

The Capital Audiofest 2022 Fab Five My selection of the Top Five best sounds of CAF 2022. Capital Audiofest 2022 Show Report By Greg Weaver Of Enjoy the Music.com

www.enjoythemusic.com

In the above example 4 out of 5 systems featured tubes in the amplification chain with 2 out of 5 featuring 300B's. 2 of 5 also featured tube DAC's including the one SS amplified system.

 

[charles1dad]

What ever the case may be with tubes and particularly SET and distortion. They consistently provide the most natural sound I have heard from recordings. The end result is all I care about. The debates /argument can continue for eternity.
Charles

 

[Gregadd]

What has a more distinct sound than solid state? But it always seems to draw a pass.
"The Mola Mola Tambaqui DAC, to me, is like listening in on the recording session. The DS never gave me that experience." [Text Omitted] PYP
Amen

 

[the sound of Tao]

What ever the case may be with tubes and particularly SET and distortion. They consistently provide the most natural sound I have heard from recordings. The end result is all I care about. The debates /argument can continue for eternity.
Charles

+1 tubes for life… or is it just being SET for life…

 

[Gregadd]

I think we should acknowledge specs were designed to favor solid state. THD eg

 

[Atmasphere]

I think we should acknowledge specs were designed to favor solid state. THD eg

No- we can't do that. THD was all there was in the old days, back when tubes were King.

Nowadays we can display the distortion spectra- and actually see why a tube amp sounds the way it does or why a solid state amp sounds as it does. This should tell you something: If you build a solid state amp that has the same distortion spectra as a tube amp, it will sound like one too.

Audiophiles, IMO have grown too used to thinking the spec sheet tells you nothing about how it sounds, because for most of the last 100 years that was true. That started to change in the 1990s and today (if all the measurements are actually made) you can tell how the amp will sound from the measurements if you understand their meaning. IOW there is a very direct link now between what we can hear and what we can measure that didn't used to exist.

 

[Gregadd]

No- we can't do that. THD was all there was in the old days, back when tubes were King.

Nowadays we can display the distortion spectra- and actually see why a tube amp sounds the way it does or why a solid state amp sounds as it does. This should tell you something: If you build a solid state amp that has the same distortion spectra as a tube amp, it will sound like one too.

Audiophiles, IMO have grown too used to thinking the spec sheet tells you nothing about how it sounds, because for most of the last 100 years that was true. That started to change in the 1990s and today (if all the measurements are actually made) you can tell how the amp will sound from the measurements if you understand their meaning. IOW there is a very direct link now between what we can hear and what we can measure that didn't used to exist.

I guess the student has not surpassed the teacher.
IIRC it was a wise tube amplification manufacture who opined that even and odd order distortion were rolled into one THD spec to disguise the superior measurement of tube amps.
There is a difference between specs and measurements. For example, the difference between the specifications FR curve on the Meze 99 classic headphones I recently purchased, and a less biased measurement. I don't think they are intentionally misleading. There are any many ways to manipulate specs. I am sure an expert like you are no influenced. To put your best foot forward so to speak. That will obscure a proper analysis by an expert like you.
Thanks for clarifying.

 

[PYP]

No- we can't do that. THD was all there was in the old days, back when tubes were King.

Nowadays we can display the distortion spectra- and actually see why a tube amp sounds the way it does or why a solid state amp sounds as it does. This should tell you something: If you build a solid state amp that has the same distortion spectra as a tube amp, it will sound like one too.

Audiophiles, IMO have grown too used to thinking the spec sheet tells you nothing about how it sounds, because for most of the last 100 years that was true. That started to change in the 1990s and today (if all the measurements are actually made) you can tell how the amp will sound from the measurements if you understand their meaning. IOW there is a very direct link now between what we can hear and what we can measure that didn't used to exist.

From the Mola Mola website regarding their Kaluga amplifiers: "Unprecedented low distortion, noise and output impedance combine into what scores of enthusiastic users unanimously describe as “no sonic signature at all”."

Is "no sonic signature" possible? My subjective view is that the amps are transparent, but I would have a hard time defining that term. One imagines that the music is simply "there" in front of and around you.

Further regarding their measurements: "For instance, the two supposedly unassailable strongholds of class-A amplifiers are linearity and output impedance, at high frequencies. Plotted on next page are the output impedance as a function of frequency and the output spectrum in a high power (400W), high frequency IMD test. In both cases Kaluga outperforms any power amplifier, regardless of technology, operating class or asking price, of which such test results are available."

 

[Atmasphere]

Is "no sonic signature" possible?

As long as distortion exists, no.

 

[PeterA]

As long as distortion exists, no.

is it possible for distortion to exist and be beyond our ability to perceive it or to recognize it as such?

 

[morricab]

is it possible for distortion to exist and be beyond our ability to perceive it or to recognize it as such?

Not completely but that is part of the SET success

 

[MadFloyd]

Not completely but that is part of the SET success

Are you saying that a valued attribute of SET amplification is that it's hard to hear its distortion - or that the distortion simply sounds musical?

 

[Atmasphere]

is it possible for distortion to exist and be beyond our ability to perceive it or to recognize it as such?

That is what some say. The numbers guys will tell you -70dB is fine. IMO/IME the distortion needs to be less than -105dB (0.0005%). This is simply because when you have distortion that low, its likely all higher ordered harmonics. The ear has over a 120dB range and uses higher ordered harmonics to sense how loud a sound is- so you can see that -75dB isn't going to work... or even -100dB...

Are you saying that a valued attribute of SET amplification is that it's hard to hear its distortion - or that the distortion simply sounds musical?

SETs work because the 2nd and 3rd harmonic are so prodigious that they mask the higher orders. So the amp sounds rich and musical, since those harmonics are musically pleasing with the fundamental tone.

The problem of course is that distortion obscures detail. For that reason, to get the most out of an SET the speaker needs to be so efficient that the amp is never run past 20-25% of full power (-6dB of clipping).

Push-Pull amps, if combined with single-ended circuitry, like the Dynaco ST70, will tend to exhibit a bit of a 5th, which IMO is why the SET guys tend to not like P-P amps. But if you run the PP amp fully balanced the 5th is less prominent and so the amp can be smoother than an SET, even though the 2nd might be lacking. For this reason P-P amps have a greater usable amount of power, up to at least 90% of full power.

But you can see this all about sculpting the distortion spectra. The best designers seem to understand this; Nelson Pass or John Curl for example.

 

[PeterA]

That is what some say. The numbers guys will tell you -70dB is fine. IMO/IME the distortion needs to be less than -105dB (0.0005%). This is simply because when you have distortion that low, its likely all higher ordered harmonics. The ear has over a 120dB range and uses higher ordered harmonics to sense how loud a sound is- so you can see that -75dB isn't going to work... or even -100dB...

SETs work because the 2nd and 3rd harmonic are so prodigious that they mask the higher orders. So the amp sounds rich and musical, since those harmonics are musically pleasing with the fundamental tone.

The problem of course is that distortion obscures detail. For that reason, to get the most out of an SET the speaker needs to be so efficient that the amp is never run past 20-25% of full power (-6dB of clipping).

Push-Pull amps, if combined with single-ended circuitry, like the Dynaco ST70, will tend to exhibit a bit of a 5th, which IMO is why the SET guys tend to not like P-P amps. But if you run the PP amp fully balanced the 5th is less prominent and so the amp can be smoother than an SET, even though the 2nd might be lacking. For this reason P-P amps have a greater usable amount of power, up to at least 90% of full power.

But you can see this all about sculpting the distortion spectra. The best designers seem to understand this; Nelson Pass or John Curl for example.

Ralph, And even Vladimir Lamm. I directly compared the Pass XA160.6 (160w) to Lamm M1.1 (100w) in my system using the Magico Q3 speakers. The Lamm had much more clarity, dynamics, openness and natural sound, while the Pass seemed grey and muffled. These SS amps were likely using much more of their power to drive the very inefficient Magicos than do my 18 W Lamm SET ML2s driving my 105dB efficient 16 ohm full corner horns. I likely use one watt most times, well below the 20-25% of full power, though I do not know for sure. I suspect that I use such little power that distortion is relatively low for SET.

 

[morricab]

ZB

Are you saying that a valued attribute of SET amplification is that it's hard to hear its distortion - or that the distortion simply sounds musical?

That it is hard to hear it’s distortion due to the specifics of how human hearing works. Your ear/brain mechanism generates its own distortion, which results in masking if the pattern generated is similar to the ears own pattern. The closer the match the better the distortion “hides”. The pattern itself matters because hearing is exceedingly complicated interplay between input signal of ear vibrations and mental processing.

 

[Atmasphere]

ZB

That it is hard to hear it’s distortion due to the specifics of how human hearing works. Your ear/brain mechanism generates its own distortion, which results in masking if the pattern generated is similar to the ears own pattern. The closer the match the better the distortion “hides”. The pattern itself matters because hearing is exceedingly complicated interplay between input signal of ear vibrations and mental processing.

A simpler way of putting that is the 2nd harmonic is so close to the fundamental- its only an octave away so innocuous. Similarly, the 3rd harmonic is an octave and a half and also always at a much lower level than the 2nd (if the 2nd isn't present, still at that lower level). So not just masking- but musically Ok (if you have a keyboard instrument around this is easy to demo).

 

[DaveC]

I think the thing with SET amps is they are more psychoacoustically correct vs others in terms of distortion spectra, no zero-crossing issues, no issues with mismatched halves of a balanced amp, etc. so when properly implemented the result sounds very good, it's closer to what the brain expects to hear and in the best cases it's not identifiable as a tube amp at all.

On distortion spectra, the idea that some are benign and others are fatiguing and unpleasant has been around for a long time of course, in fact there's weighting systems for the order of THD where higher orders are given more weight, which is one step closer to correlation with what we actually hear.

In any case, there's no perfect amp, no perfect component, etc. so everything really does homogenize the music, this is an undisputable fact. It's just a question of how much it subjectively matters, how large the effect is. All we have for comparison is other gear that is also imperfect, and that's exactly what we're left with, comparing imperfect gear and deciding which homogenizes the least. Just because one piece of gear homogenizes less than another doesn't mean it's perfect.

 

[PeterA]

I think the thing with SET amps is they are more psychoacoustically correct vs others in terms of distortion spectra, no zero-crossing issues, no issues with mismatched halves of a balanced amp, etc. so when properly implemented the result sounds very good, it's closer to what the brain expects to hear and in the best cases it's not identifiable as a tube amp at all.

Nicely put, Dave. I agree with this comment in bold and do not associate my SET amps with sounding like "typical tubes". On the other hand, a recent visitor who owns SS amps claimed the exact opposite to me, that the sound is easily identifiable as a SET amp. He said he hears the SET distortion, and though he likes it, says that it is a strong flavor and makes everything sound pleasing and similar. We had to simply agree to disagree. My former SS amps made recordings sound much more similar to each other, and in hindsight, I now think they homogenized the sound much more.