Fixed my power problem for $140
Good news - bought a Dehavilland preamp and it is amazing.
Bad news - every time my electric space heater clicked on or someone used the microwave or anything that draws lots of current, I would hear a pronounced click through my speakers - like a relay click. Loud. So I think the power dips were causing a relay inside the preamp to trip/reset.
Good news - after some search and a refusal to spend $1000 on an esoteric power conditioner, I found Furman. I ended up getting the PL-8 C. And problem solved. Woohoo. I can't say I noticed an improvement in the sound per se, but I usually listen with everything else in the house off - lights included. But now I don't have to worry about those things or my teenage daughter microwaving a burrito.