I've been in blind amp tests and I can emphatically say "No", I can't tell the difference in amps. I seriously doubt if anyone could tell speaker brands unless they've been repeatedly exposed to those speakers, have material they're familiar with, know which brands are in the test and there's a "tell" about them. For instance, put my Paradigms and Maggies side-by-side and yeah, it's easy. Especially on metal or acoustic.
Blind fold hearing test
How many of you could be blind folded or put in a room in total darkness and know what kind of speaker amp and preamp are being used. Another words if u came blind folded in my listening room could u tell I was using a Krell amp a ARC pre and B&W speakers? Not necessarily the models but more or less the brands. I would be the first to say for me it would be no. Would love to see how many of you could. Should be interesting.