@jea48 I do indeed have 2 dedicated 20 amp circuits, and am fortunate to have my main panel box in my listening room, in fact, from my panel box to my outlets is a direct vertical drop of approx. 4 ft , and yes #10 awg. None of my power cords are stock. All are AudioQuest NRG-4's, and all are either 3 ft, or 6 ft.
Power out of my conditioners is a rock solid 120v, although I have not checked this under high volume conditions.
It all just may be that I am the culprit here. Herman makes a good point, that it may be louder than I realize. After so many years of working in extremely loud industrial settings (metal fabrication) and add to that my years as a hard rock guitarist, some hearing loss may be more than I realise. I do have a SPL meter, but haven't used it in years. Perhaps I will dig it out of storage and see what actual values are being presented in my room. Will follow up with these readings tomorrow.
Thanks all.......