Thompson,
I have told this story a number of times, so apologies to anyone who has heard me recount this before.
As a newly minted electronic engineer, I went to work at the research and designs group of a well known broadcaster. At the time, the majority of speakers used for studio monitoring were in-house designs, and the speaker team were highly regarded. As a hifi enthusiast, every now and then I would go and pester the speaker team to hear their speakers. Eventually they took pity on me and invited me into their auditioning room - which had 4 or 5 of the development models of their latest design. They played each speaker in turn to me, explaining the problems, and how the next version corrected the problems in the previous version, but in turn had problems of its own.
I felt pretty good, I could clearly identify all of the problems they described, and clearly hear how later versions had solved the problems, and identify the new issues that later designs introduced.
Except they had only played one speaker.
A lesson that has stuck with me - don't ever trust your ears. Auditioning has its place, but you need to ensure that the biases that may be present are compensated for, or all you are listening to are your own expectations.
- and as for mains cables, a bit of research into how power supplies work would clearly illustrate that the claims made for mains cables are nonsense. You may well believe that they make a difference, and maybe you have some problem somewhere in your system that moving all the stuff around to change cables effects, but the mains cables themselves really won't (and can't) make a difference.
Perhaps you could link to a independent study, or test, or research paper that in any way justifies a view that changing the mains lead on a domestic hifi component results in a change in sound quality. I have looked, and I can't find anything (the 'studies' published by cable manufacturers to justify their own cables really don't count).