Home Tube DIY Asylum

Do It Yourself (DIY) paradise for tube and SET project builders.

RE: Listen for yourself

Perhaps I should expand upon my previous response to your posting.

I apologise if I picked the wrong word by describing the sound from an SET amplifier as "pleasing," since it might perhaps have carried a connotation of condescension that was not intended. I was just looking for a word that conveyed the idea that the sound gave a more satisfying all-round experience for the listener. And in that sense, I would describe a system that "had more instrument texture, nuance, natural clarity and presence than anything I heard heard to date" as a system that had a more "pleasing" sound. Perhaps there is a better word I could have used.

Now, as regards my statement that I suspect that these phenomena can be accounted for in terms of rationally understandable scientific principles, let me expand a little on this. Of course, ultimately, one (or at least a scientist such as myself) would wish to be able to explain everything we observe in terms of the most fundamental concepts and building blocks (quarks, leptons, strings,...????), but obviously at present that is not feasible. But explanations of phenomena in terms of more general observed phenomena can also be perfectly "scientific," even if they do not go all the way back to the level of the fundamental building blocks.

In the present context, I would take the observed psycho-acoustical characteristics of the human mind and ear as scientific phenomenological observations. A couple of examples are:

1) Humans find mixtures of frequencies that are related by simple rational ratios to be pleasing to the ear, and on the other hand irrationally-related mixed frequencies tend to sound unpleasant. Based on this observation, one can predict that if one made a sound-producing system in which all frequencies were shifted upwards or downwards by a constant additive amount, then music played through this system would sound absolutely dreadful. And this is, I believe, borne out by experimental observations. (A simple way to test this is if one has a shortwave receiver with narrow-band filtering that can block the central carrier frequency, and one then replaces this with a local BFO operating at a slightly different frequency.)

2) Humans find that the addition of the second harmonic to a tone or set of tones can provide a pleasing (in my generic sense) alteration to the overall effect. In particular, in a piece of music it can lead to an augmentation of the feeling of "liveliness," and maybe it can allow the brain to interpolate or extrapolate and give more of a lifelike overall experience. (Research in psycho-acoustical phenomena, as with many other aspects of the interaction of the brain with our exterior senses, seems to indicate that the brain does an amazing job of "filling in" the things that are inadequately conveyed to it by our sense organs.)

As a rather trivial hypothetical example, if it were the case that broadcast music stations used single or double-sideband AM transmissions where the carrier was removed and needed to be restored in the end-user's receiver, then one could easily make a general "scientific" observation that the best-sounding receivers would be those that restored the correct suppressed carrier frequency, rather than one that was displaced up or down by some amount. This would not be in the least bit controversial.

In a similar vein, it is a perfectly legitimate scientific endeavour to look for what characteristics of an SET amplifier might be responsible for giving humans the feeling that the performance is more "alive," or have more instrument texture, nuance and clarity. It seems reasonable to suspect that the phenomenological observations noted in point (2) above could be playing an important role, especially when one notes that one of the most striking distinguishing features of an SET amplifier is the relatively large percentage of second-order harmonic distortion.

Thus, I don't see why there should be anything controversial about the suggestion that if one can identify certain generic and measurable characteristics of SET amplifiers that distinguish them from most other amplifiers, then it is quite likely that it is these characteristics that are playing an important role in accounting for why they produce the audible sensations ("presence," "nuance," "instrument texture," or whatever) that they do. Thus, technical measurements of an amplifier's distortion and other characteristics (such as frequency response) might very well allow one to predict what kinds of overall impression it could give to the listener. You may be right that there are further characteristics of an SET amplifier that have yet to be identified and measured, but I wonder if there is really solid evidence for this?


Edits: 07/07/17

This post is made possible by the generous support of people like you and our sponsors:
  Parts Connexion  

Follow Ups Full Thread
Follow Ups


Post a Message!

Forgot Password?
Moniker (Username):
Password (Optional):
  Remember my Moniker & Password  (What's this?)    Eat Me
E-Mail (Optional):
Message:   (Posts are subject to Content Rules)
Optional Link URL:
Optional Link Title:
Optional Image URL:
Upload Image:
E-mail Replies:  Automagically notify you when someone responds.