Marty -
I am forced to conclude that it has very little to do with your room and everything to do with your AC, dedicated lines notwithstanding. Here's a low cost solution. Get a high-current Ultimate Outlet, mini-Lab Cable and Juice Bar from PS Audio - 30 day money back guarantee. Plug the UO into your wall via the mini-Lab Cable. Plug your amp into the UO and the rest of your gear into the Juice Bar - plug the Juice Bar into the second socket on the UO. Let it all settle in for a few days. I think you'll be shocked at the results.
Just because you have a dedicated line doesn't mean that you have clean AC power.
I am forced to conclude that it has very little to do with your room and everything to do with your AC, dedicated lines notwithstanding. Here's a low cost solution. Get a high-current Ultimate Outlet, mini-Lab Cable and Juice Bar from PS Audio - 30 day money back guarantee. Plug the UO into your wall via the mini-Lab Cable. Plug your amp into the UO and the rest of your gear into the Juice Bar - plug the Juice Bar into the second socket on the UO. Let it all settle in for a few days. I think you'll be shocked at the results.
Just because you have a dedicated line doesn't mean that you have clean AC power.