I DO NOT KNOW HOW TO DO A QUOTE SO THAT IT SAYS WHO THE QUOTE IS FROM... THE FOLLOWING ARE FROM M0002A, STHAYASHI AND GREEN SHOES, IN THAT ORDER.
One of the world's largest computer manufacturers had to recall hundreds of thousands power cords because the gauge of wire used was too thin for its intended use, so not all power cables are equal.
Very true. If the AC cord simply cannot pass the current required by the PSU then you do indeed have a problem. No argument there. I think that this is a pretty low criterion for acceptable cords, however—insisting on the EXACT stock cord because you are worried about that seems a little over-the-top.
If you live within 90 minutes of Pittsburgh, I'd LOVE to visit and perform a double blind test on you. I've made this challenge to Ed, but sadly he lives too far away for me to casually visit.
Ditto anywhere near Nashville. I have seen the inner workings of major studios that run on "tech power" (or the orange plugs, for the uninformed) and the incredible amount of money that they spend on completely isolating the transformers from any possible corruption source, lights, etc. But this is to eliminate the dreaded "60-cycle hum" from coming through on audio tracks with guitar amps, tube mics, etc. I too don't see a way that a power cord can have "character", like swapping a mic would; the only change would be the presence/absence of 60-Hz badness.
I am afraid that I live in Santa Barbara, Ca. … I already did a double-blind test with a friend/skeptic (see my above post on friend/engineer/skeptic) but we didn’t really follow all the way through. After the first time he switched the cables to see if I’d really been listening, HE found the difference so easy to hear that HE stopped the test because the difference was so obvious that he concluded that there was really no point in going on. The "60-cycle hum" is a result of interacting electronics that have different ground potentials. Eliminating this is, of course, a pretty good idea. To say that the quality of the AC into the gear cannot be heard (in addition to this) is simply not correct, however. Think of it this way, all that analog audio (or video) equipment does is move and amplify information "stored" as electricity; ANYTHING riding along on this electricity will raise the noise floor, obscuring and/or screwing up the low-level musical info. (and/or an insufficient PSU will truncate transients, leading to duller, lifeless audio as well). This is why many audio manufacturers (the good ones, anyway) go to such lengths designing in filters, chokes, isolation transformers, batteries, and other design exotica into their PSUs—clean power REALLY matters. The better this on-board regulation, maybe, MAYBE the less effect that designer cords and conditioners will have sound quality… though I have never, ever heard a component that was unaffected by a AC cord swap. NOTE: Different need not be BETTER, and often is not, it's just different (for example, Shunyata cords are consistently dynamic and “alive”, while the Kimber cords are consistently smoother and more romantic; I prefer the former, my roommate likes the latter—which is “better”, I cannot say.
In any case guys, don’t let my living 2000 miles away stop YOU from taking the test. I have no doubt that both Pittsburg and Tennessee, being a major metropolises, have a number of hi-end audio salons around. When you have a few hours to kill, drop by one and hear what you hear. I am not telling you that I am right, I am just saying that before you go around challenging others JUST LISTEN for yourself—you may be surprised. In fact, I’ll up the ante: why not find a salon that stocks hi-end AC wall receptacles—see if you can hear the difference by just switching out the plug into which the (same) AC cord is connected—I bet you can (I use Albert Porter modified cryo-treated Hubble Hospital-Grade AC outlets in my own system). Even better, see what happens when you lift you power and speaker cable off the floor (only if you have carpets). I’m not telling you what you’ll hear (if anything), just TRY IT.
Do not try this with a BOSE (
Buy
Other
Stereo
Equipment
) or other sucky system (think: anything I could buy in a Circuit City or Best Buy)—in such a case, I doubt that you would hear any difference at all.
)
.. You, ... You, ... You mean, ... we don't all do it !!! 
. However, it is not a luxury that I can currently afford; perhaps when I can finally afford those Cello towers I've wanted for years (not likely) powered by a nice McIntosh amp I'll think about it