What power conditioner will help in my situation?

Have a qualified electrician run a dedicated line or two. It really doesn't cost that much to do so. They really do know what they are doing and how to do it. worst case, run on wall wiring in on wall conduit from another circuit (preferrably one not used frequently) to your listening room.

enjoy

Just shut off the fan when listening to your stereo!

I turn off the AC or heat, due to fan noise and circulating air, when I listen.

"I turn off the AC or heat, due to fan noise and circulating air, when I listen."

I guess many of us do. I do, but there is that other problem, "Is your refrigerator running?" which despite the old joke many of us do wish it would runaway considering the disturbing noise these modern refrigerators make. Smaller homes where listening spaces are in close proximity to kitchen is real concern, for unlike AC/heat shut off at thermostat, shutting off a refrigerator full of food invites real risks.

Aperez -

a dedicated line to your system would be the best option.