@OP
Don’t know your situation as to what an Electrician might run you to add a couple ded ckts, and one should always run at least two, as the cost will be about the same as it is for one, generally. If both are coming from and going to the same place. Ensure both are on the same phase.
Power regenerators are pricey. They alter the sound too.
Getting better dimmers is another idea. Disposing of them is too.
When I have a main system up and running my DD 15 Velodyne sub is running off the same non ded ckt as the lighting in that room which controls low voltage LEDs off a Lutron 600watt Dimmer I’m not experiencing any noticeable abhorrent sonic issues.
You might want to look into somebody’s one or two gang passive outlets as a sort of power line conditioning.
As for a UPC, only employ full wave rectification. Many UPC are half wave only such as those for computers and office gear. The halfs go for like $200 and less. Full wave bridge rectified UPCs are more expensive. In either case these are stop gap half measures for the situation you are experiencing.
Cheapest path = Remove the dimmer
For a bit more = Replace the dimmer with a better one.
Fix things and improve the system = Add ded ckts.
For still more $$$ if #3 is not enough = look into either passive or active power line conditioning.
I have four ded 20A ckts. I use 4 passive PLC of various brands.
Passive PLC will not as much affect the sound as will active PLC.
Good luck.
