Hmmmmn... I wonder if I hooked QS8 surrounds to speaker pair #4 and QS8 backs to speaker pair #5 on the switcher:

I wonder if there is any analysis worth trying with them, like A/B the two amps at a given 1) amp volume know level 2) See if there is a discernable SQ difference at a matching SPL/dB level between amps? Actually, I guess this is what I'd be looking for on the Amp A/B switching on one or more pairs of fronts, so I'd get the 'amp difference' more easily noticed there (if at all?)

Dave

"In theory, practice and theory are the same. In practice they're not."