According to UL and NEMA, the only difference between a 125 vac 15 amp receptacle and a 20 amp receptacle, is the plastic cover governing the type of plug it will accept. I installed two dedicated 12/2 lines, each having hospital grade single 20 amp receptacles, for my monoblocks. They’re both on the same buss at the breaker box. All my “hi-fi” receptacles are on the same buss. As far as the receptacle covers influencing the overall sound, that’s something I’ve never considered. Unless you have a Faraday cage, we are all exposed to unending amounts of EMF and radio waves going through us and our listening rooms at all times. IMO, such nuances as special receptacle plates have little effect on the sound. I do realize that if you add a lot of subtle tweeks to your system, they add up, but to diminishing returns. I know-unless one has tried it...etc etc.
