Well, as Ken said, and drawing on some caveat I ran across long ago, if you have two amps connected to one set of speakers, even with one of them off, the current from the one that is on, is going into the speakers and then back down the other set of speaker wire to the speaker outputs of the other amp, and I think current flowing INto an OUTput is a "no no." I do hope that someone who knows what they're talking about will chime in here (No offense meant, Ken. You're right about the function of stacking bananas. )

Jack

"People generally quarrel because they cannot argue." - G. K. Chesterton