Sneer all you like, Putter, alters my opinion not one iota.
I didn't say anything to the effect that only audiophiles could hear differences -- don't put words in my mouth, thanks. In fact I have average hearing a best, maybe less than average given my age, etc. What I do -- which you might not -- is LISTEN without the prejudice that there are no differences to be heard. (Who's the bigot now?)
As for room distortions, etc., sure, but if all else is equal except the amps, then it's the amp difference you're hearing.