Let's be clear: I was talking about what we hear, not about measurements or controlled testing.
In truth I don't know whether I could reliably distinguish, say, my Pass amp from my VTV in the usual type of ABX testing. But sitting through hours of listening my ears hear differences. If confirmation bias means you "hear" what you "see", how come that isn't always to the case? Why didn't I hear my $5500 Pass as better than my $1500 Purifi? What a mystery!?!
No more discussion from me on this thread: clearly I'm just hollering down a well.
With all due respect, it's always a mystery. Always. That's the point of wanting some form of controlled testing.
What we expect, and therefore what dominates confirmation bias, happens both consciously and subconsciously, it seems to me. (I am not a psychologist, but rather just a dilettante observer of human behavior, particularly my own.) I'm not sure I can predict whether the conscious or subconscious part will dominate my summary expectation and bias in any particular context. I may
want the expensive amp to be better, while believing in my heart of hearts that it isn't, and that's just two of maybe four or five levels at which bias may be at work. It is indeed a mystery; were it not, there would be no need for controlled testing. I have in the past asserted that my bias was opposite of the conclusion, and therefore irrelevant to that conclusion, but I'm frankly not so shallow that I can be sure my conscious bias was really dominating my perceptions.
From the standpoint of my own preferences, I may be quite happy with one or the other. I may actually prefer coloration of a Pass amp versus a lack of coloration of a Purifi amp, for example. Or I may prefer the reverse. I can have those preferences even if I can show that I can consistently hear a difference. We live by sight and sound, so if the appearance, brand, story, and ownership experience of an amp makes it sound better to us, then, well, it does. But that doesn't mean my response is transferable.
There is nothing about blind testing that requires short listening excerpts, it seems to me. When Toole and Olive were conducting blind preference tests, they allowed the listeners to listen as long as they liked to each sample. If I listen to one for a whole week or month and write down my subjective response to it in a notebook, and then listen to a different one for a week or a month (or an hour) and write down my impressions, then listen to "X" to try and correlate it (based on my notes, after the fact) to one or the other, and keep doing so long enough for a pattern to form, there might actually be some differences that can be noted, without the need for rapid-fire ABX testing. The idea that long-term listening is required and therefore controlled testing is unhelpful is simply a mistake. The requirement is to remove sighted bias. There would need to be other controls, such as listener being unable to control volume (in order to preserve level matching), which would be inconvenient, but not fatal to the idea of a longer listening period. If the hypothesis is "with extended listening over the course of a week, Amp A sounds different than Amp B in relation to Amp X," then I can construct the necessary controlled listening test. Statistical significance would require a very long time, so most don't do it this way. But that is a matter of convenience only, and of sample size and resulting reliability of the conclusions. Such long tests would certainly lack the sample size to confirm with any confidence that A and B are the same (or different), but even the inability to confirm that easily would debunk in my own thinking any notion that the differences are profound.
For a fun read on the topic of blind testing, probably old news for most here, see:
https://www.stereophile.com/features/141/index.html. That series of letters contained quite some bit of violent agreement, in addition to some incomplete understanding of statistics and some false conclusions, but I thought the 12-page back-and-forth ended well.
Rick "who doesn't have the money to waste on stuff that is merely expensive" Denney