Don’t have much to add to what has already been said, except adding a dedicated circuit (20A), a high quality receptacle, and a power cord can’t hurt. Also, a power conditioner is a good idea, even if just for surge protection, but I’ve found that it does help quiet things down a bit. You only have to buy this stuff once, pretty much. Alternatively, If the benefit of all this stuff is purely psychological, you could go to a hypnotist and have him/her convince you that it has all been done already. Probably cheaper to just actually do it.
Power Cables and Wall Sockets
Without knowing for certain, it seems to me that power cables can only be as good as the in-home wiring coming to the wall socket. Is it possible that those who use expensive cables have improved the wiring to the socket? Or is the power from most wall sockets normally excellent, but is limited by conventional power cables?