At one point or another in my auditioning history I have, of course, heard differences among speaker and amps, but also as I believed ...
CDPs and DACs
Speaker cables
Interconnects
Vacuum tubes of various makes and vintages
Interconnects, analog at least
Fuses used in speakers
I'll admit that I've never even thought I heard difference among power cords . RFI/EMI filters, or vibration control devices, although these these are pretty dependent on the individual environment.

What I allow -- that so many other people do not -- is that the differences I supposed I heard might have been my imagination or my mood at the time of listening.

elapsed, contrary to you estimation of Aczel's comments, the "lie" I most disgree with is #10, that is, there are no golden ears -- I think some people do indeed hear better than others. (I'm no "golden ear" myself.)