Question: is it absolutely necessary to have two separate amplifiers? Can you do something like use a 4-channel amp (or 4 channels of a 5 channel amp) and get the same thing as a pair of stereos (or a quadrant of monos)? I've heard before that you want to have separate power supplies (or torroids at least) for this. How much of a difference does that make?

Ok, so there was more than one.