I have two. One for power amp(s). The other for pre and source. The idea is to create "quiet" circuits that are receiving as little influence as possible from other power users in the house. Makes sense to me that amps may draw more power and therefore may create "noise" of their own. I suspect the preamp would be highly sensitive to noise so that's why I have 2. I further suppose one for each piece would be the ultimate but I don't have room in my panel for 6 (amps, pre, CD, phono pre, turntable) dedicate 20 amp circuits.
