I for one am glad to see a "thorough" evaluation of this amp. Clearly, this amp did not fit Kchahoc's system and/or tastes. But the information he provided is very useful to me, and I hope Fiddler will post his own review of the amp on his ribbons. We all know that "synergy" is far more important than how "good" any particular piece is.
I suspect that with the B&W's (metal dome tweeter, kevlar woofer) the MF with its warmer midrange would result in a more pleasing sound, than the PS or Bel Canto for example. Perhaps it would be more musical if the PS was mated with a tube preamp?
It is also possible that there is something "wrong" with the PS amp? In my experience, first generation production runs from high end companies are sometimes plagued with problems, either due to parts inconsistency or shipping problems, etc. I guess the good news is that PS offers the 30 day return, right? maybe if Kchahoc reported his findings to PS Audio and returned the amp, they might investigate to learn if there is indeed something wrong with that particular specimen, or if it was just a case of system conflict.
All in all, thanks to Kchahoc for reporting his findings in such detail (cable swaps included). Much more useful than some of the other "greatest amp ever" reviews found here and in audio magazines in general. NOTHING works with EVERYTING in my opinion, and I'd rather know what does NOT work together, than read another glowing review which you have to "read between the lines" to really grasp any useful information.