As the thread originator.....I'm still searching for an answer. My brain tells me it should be IC's connected to source components. The old theory that if you don't get the information at the beginning of the chain, everything downstream suffers. Lately I've been changing a lot of cables in and out of my system and my preconceptions (and this theory) are not holding up. What's having the most discernable impact is speaker cables, by a wide margin, followed by IC's (source and amp/pre about equal) with power cables bringing up the rear. Maybe this question is so system dependent that there is no definitive right answer, but it seems to me there should be.