If you have four dedicated circuits literally, you should put one EP-2750 ground filter on each. I don't see a real need for 4 circuits though; you could put everything you have on one proper dedicated 20-amp circuit or also minimally on two dedicated 20-amp circuits splitting your front-end components (DAC/Preamp, Transport/Streamer?) on one circuit and your subwoofer and amp on the other. When spliting a system across multiple circuits, you have to make 100% certain that the grounding is perfect and that both circuits see the same aspect of ground (not an electrician so don't know the right technical words to utilize). As an aside, I had a killer 7.1 HT setup with all separates for a few years, HT Processor, 2-ch pre-amp, universal transport, DAC, clock, separate amps for bi-amped fronts, separate center and separate (4) rear channels, subwoofer, high-end HDTV, game consoles, video parametricEQ processor (Lumagen) and LFE bass parametricEQ processor; I did NOT need 3, 4 or more dedicated circuits; I ran off one 20-amp circuit and later two at most. I don't think you need to overcomplicate by going to 4 dedicated circuits FWIW....