I am a novice audiophile, but I would try one thing, it is simple and easy. If you are running all this on standard outlets as is normally wired into a house when built, most electricians will run 8 to 12 outlets on one 15amp breaker and if you are plugging all this into a few of these outlets but also have lamps and other "items" in the house plugged into this circuit also, you could be on the edge of your amp load and so I would run a dedicated 15 or 20 amp service line on a new breaker so that you are running all your equipment on its own circuit so all the juice is dedicated to just your system. Use hospital grade receptacles and you can try isolated ground receptacles as well. Seems to me you have nice enough equipment, could be a simple matter of current starvation? Easy enough to test.
carry on.
carry on.