My 2 ch setup is in a small room that is all on one circuit unfortunately, so yep, you're correct. Nothing I can really do minus calling an electrician. That would be a hard sell to the wife

Well, considering she let you buy the rig you have, I'd say she's done pretty well by you so far. A UPS sounds like your best bet cost wise - I have installed a few of them like this one and this one , and feedback was good (though only the belkin provides battery to more than 2 outlets).

Get an electrician and put your system on a dedicated well grounded circuit

Any quality UPS with more than a few hundred VA of backup power should be able to handle the transient voltage sags being discussed by the original poster. I'd stick with APC, personally. You can pick up a 1500VA unit for under $200 if you shop around. I was using a APC Matrix 5Kva unit for my theater system in my old house. That way, my components never saw anything but a clean 120v sine wave. Due to older home/wiring, the voltage was otherwise all over the place whenever the AC would come on, the fridge compressor cycled on, microwave turned on, hair dryer, etc.

Best,

Wow those are pretty pricey. I paid about $200 for my M5300. (No battery of course.) Did want to comment on one thing - she has been very gracious, you are correct. Very understanding and generous.

Power one or the other from an extension cord from another circuit to see if the problem stops. If not ,then an electrician will have to be used because the AC unit is dragging down your whole power supply to the house. The problem could be in your AC unit with a relay that is sticking or has bad contact.