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?


@analogj, the PowerQuest2 to my understanding was not designed by Garth Powell. For me it acted as a really good surge protector with some adequate noise filtering that made it a much better choice for an audio or home entertainment system than your average hardware store power strips. There really is no comparing it to the AQ Niagara series of power conditioners because the Niagara’s are audiophile grade units for dedicated hifi systems. The price of the PQ2 makes it a good place to start as you build your system or if you just want to have piece of mind protecting your audio gear. 


I took erik_squires advice earlier this year and got a Furman unit with LiFT and SMP. No degradation of sound, in fact the sound improved.

Does anyone know the difference between the Audioquest Niagara 1200 @ $999 and the LOW-Z version @ $1299

@adasdad ...you probably know the answer to that question....I'm interested in upgrading from the   PQ2

U.K. produced Puritan PSM156, it works and is much better value than anything else.