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?


Mr Carpathian,  I beg to differ.  Here in Iowa we have 140mph Derechos.  Took out 70,000 or more trees in Cedar Rapids alone.  South is getting lots of storms this spring.  Good luck and enjoy the music.

There were some good comments from atmosphere(Ralph) about what power conditioners need to do and not do recently.

AudioQuest Powerquest 2  at Audio Advisor  $200....Really sweet. Better than my $600 PS  Audio.

I suggest a Furman PST-8D. Been using one for a year without any issues in a headphone system. Didn't have a long/tumultuous break in like other power conditioners, while it also had a smaller effect on sound. I don't know how it compares to its AudioQuest competitors at its price.