Two Independent Amps From Same Power Supply?

I'm building my first amp, an ESP P3A and I'm planning on using two boards to make a 4 channel amp. If I use a large enough toroid (625VA) can I run the DC from a single power supply to the inputs of 2 (well 4 actually) amps but still be able to control the volume of each pair of amps independently?
 
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So long as the supply can provide a stiff DC voltage (i.e. it has enough current capability) to all four amps at once and the amps are reasonably insensitive to small supply variations (good PSRR), there's no problem at all using a single supply for all of them.