@cd318
The problem with your perspective on this issue, one that, in my view, is shared by a good percentage of the HUG members, is that it is too rigid.
Few would argue that anecdotal experiences are as
broadly compelling as carefully executed, published studies, but to essentially lump them all together, and so easily dismiss them, reflects a rather closed mind.
To use just one of many examples of why I believe that to be the case, consider a poster on the
Audio Science Review known as "DonH56". He is described as a "Major Contributor" and "Technical Expert", and his background, as displayed on his profile, is:
Design and now validation electrical engineer, focused on high-speed (GHz+) analog and mixed-signal circuits. Did a fair amount of audio design in my youth, including tube and SS preamps and power amps, and a servo-controlled subwoofer back when they were new and few.
I was principal trumpet of the Pikes Peak Philharmonic orchestra, have played in a few jazz and big bands around the area, led the trumpets for the Tri-Lakes Music Association for many years, done a few "pro" gigs, and sometimes play at church.
So, given that the ASR is likely the most broadly skeptical, and science/test-based audio forum in the world, it is safe to say that this member is, to put it mildly, no fool.
I noticed one of his posts on a thread related to the very topic that we are discussing, and have excerpted some bits, and linked to it below.
My assertion is usually weasel-worded as "most SS amps operated within their linear region driving most typical speakers will sound the same". Lots of ambiguity because I have not listened to, let alone measured, a large sample of amps connected to a similarly large sample of speakers any time recently. Treat all that follows as opinion.
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I suspect few of us would have a problem distinguishing a SS amp from a tube amp. The differences, measured and heard, are large enough to be clearly audible on most speakers.
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The gain structure and noise floor of the amp is in play as well; one of things I (many people) found years ago was, in blind testing, an amp with a higher noise floor was readily distinguished from another amp. We did a test with two tape (yes, 1/2" tape at that time) loops playing the same music selections using a couple of big SS amps (have forgotten which, Krell, Threshold, and Levinson were in the store at that time, among others). The speakers I’ve forgotten but I think were either Magnepan MG-20’s or B&W 801’s ca. 1982’ish. We might have run with both speakers, too long for me to recall. We inserted a 2 s silence between the selections on one tape, and went straight from one selection to another on the other. The selections were a mix of music but did not have very quiet (silent) passages. Gain matched the channels, natch. With the 2 s gaps, people easily picked out the "noisier" amp, and commented how it "filled in" gaps between piano notes, drum strikes, and such. Without the gaps, nobody was able to tell the two amps apart. IIRC the noisier one was class A but had fairly low SNR, like 80 - 90 dB unweighted, whilst the other amp was something like 100+ dB.
https://www.audiosciencereview.com/forum/index.php?threads/double-blind-tests-did-show-amplifiers-to...Note how he reports that the difference between how subjects were able to distinguish between the two amps with two seconds of silence between the selections, but not without. That alone provides a potentially important insight into why the results of "classic" blind-tests may not necessarily tell the whole story.
This person is an electrical engineer who has designed and built amplifiers, and a professional musician to top it off. Yet while he is broadly in agreement with those who claim that amps sound the same, his experiences have led him to the conclusion that it is not always the case.
Not so easily dismissed, in my view, and there are many other, similar examples of compelling anecdotes to be found.