Least Expensive Power Conditioner/Surge Protector That Won't Worsen Sound

I have an old Shunyata Hydra 6 that I'm sending off to Shunyata to repair. In the meantime, I'm curious - What's the least expensive power conditioner/surge protector that won't worsen the sound? 


I've already discovered that plugging my integrated directly into the wall sounds the best. But I have source components. I have liked the Shunyata, but just in case they're not able to get it back to like new shape, what are your thoughts? (I tried numerous PLCs at the time I bought it almost 20 years ago and I thought it, by far, sounded better than any other one I auditioned in my system, and that included the Hydra 8).


I see many users who have reported worsening sound when using the Audioquest PQ2 and PQ3.


Something like a Panamax PM 5300 or 5400?  Or the Furman Elite 15?


And what is the danger of under-voltage?


"Here in SC I've had undervoltage trip twice last year.  Once during a thunderstorm and another time during a wind storm. "

You haven't seen a thunderstorm until you've seen a South Carolina thunderstorm!

No such thing for amps.  I like Tripp lite protectors and whole house for low current devices (basically everything else). 


You can buy a used Shunyata Hydra (first generation Hydra 2 or 4) for $500.00 or so.

I use a Panamax for my HT and they’re good and priced right. They even have one plug that is for high-current amps. I use an audiophile grade basic power strip for my music system.