Tube amplifiers and interstage transformers

Charles1dad, something that has puzzled me for a long time is the also 'common argument' that triodes are the most linear form of amplification known to man, yet they have more distortion??

The fact is that they don't. Try putting a transistor in a single-ended zero feedback configuration and see what happens :)

The 'common argument' is apparently false, and should be addressed where ever it appears.

We found that by adding feedback to our OTLs we could get the distortion down well below that of conventional transistor amps, but in doing so the amp also took on some of the sterile qualities (read: brighter, less musical) that are hallmarks of amps with feedback. We chose at that point (about 1980) to eschew feedback; if the speaker thus did not allow the amp to sound right on that speaker, the conclusion is that the speaker would never sound right with *any* amplifier! This has limited our market, but the upside is that if a person sets up the amp right its hard to beat.

SETs have a similar 'weakness' (although I regard it as a musical strength) on the same account.

Transistors 'measure better' on account of the fact that the 'measurement' has almost nothing to do with human hearing rules and are simple a method of making the amp look good on paper.

Thanks Atmasphere, I realized some time ago that the present measurement standards and the sound quality have hardly any correlation. In some ways to a degree it's almost an inverse relationship. Stereophile's JA measurements compare to Art Dudley's listening impressions is an example.Measurements do have a relevant use, they just aren't useful as a predictor of sound quality. I don't know why the laws of human hearing are'nt appreciated more and respected.
Regards,

I don't know why the laws of human hearing are'nt appreciated more and respected.

A lot of what we know about human hearing rules has only been worked out in the last 35- 40 years. But by 50 years ago, most of the understanding of how to analyze audio products was already in place. To get the really low THD specs you have to use feedback; when it was discovered that the human ear uses odd orders to detect volume (and also that trace amounts of odd ordered harmonic distortion is really irritating to the human ear), the fact that negative feedback was contributing to that became an 'inconvenient truth'; essentially the audio industry paid no attention and may have even swept the discovery under the carpet.

So for the last 45 years or so the spec sheet has told us nothing about how an amp sounds- in fact as you say may even show an inverse relationship to the sound of the product. But changing the way the audio industry does things is hard- there are a lot of companies that simply will not accept human hearing rules as important, even though they pay lip service.

The result is that audiophiles, no matter what they have read or heard from others (and no matter who those others are) have to audition things for themselves. You would think that the spec sheet would help in that purpose- what else could it be for??

Of course the issue is pursuit of the almighty dollar. Tube amplifier power is more expensive than transistor power and high efficiency speakers are more expensive than low efficiency speakers. But the hype is that the cheaper transistors and lower efficiency speakers are somehow better because of the 'specs'! Whatta world!

hey,

Measurements do have a relevant use, they just aren't useful as a predictor of sound quality.

bingo! Measurements are objective, sound quality is subjective and there is a word that describes ambiguous blending of the two in order to manipulate.

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dave

The thread has become really interesting!

I also believe that specs are just a way to measure audio, but those measurements do not have a direct relation with how we humans perceive and process sounds.

"So for the last 45 years or so the spec sheet has told us nothing about how an amp sounds"

Great Line!!

The mechanism that works inside our ears is not the same mechanism that works in the machines that produce those amp specs. We are a much complicated machine with lots of nuances to take into account.

As Atmasphere said, most of the companies need something to show or rumble about and most of the time is something related to specs, although some of them play the review game very well...

We just need to listen and that is always a pleasure.

Personally, I regard that the pleasure of listening to music in a good hi end system that is able to conjure the emotions of the musicians to our living room is a kind of spiritual quest that tries to find in sound a connection with the invisible, with something that lies beyond the organized noise, that somehow make us aware of some intuitive knowledge we have lost along the years as a civilization...

How can we measure that?