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

Furman Elite 15PFIs - good units, and you can find these used at good prices at Audiogon, US Audiomart, and HiFi Shark.

I avoid using the AQ Niagra high current outputs and now plug my amps directly into the wall socket- Proves to be sonically inferior through the AQ Niagra

To me this unit was a total waste of money .

If they are doing it right, parts are marked up 5 times in manufacturing. The other costs you mentioned should be marked up 3 times, including labor. Then, that price is doubled twice before the point of purchase. The margins in audio are what makes it all go round. 

Brick wall out of PA for $300, matched several-line conditioners in the $1500 

range andSterphile used to have it in class-B  which is respectable ,I bought 2 and find them pretty effective ,I upgraded mine by upgrading  several internal capacitors 

and installed a Furutech power cord to make it better still , most everything can be bettered if you look inside it ,whst most Audiophiles don’t realize is Thst on average 25% of the-cost goes into the build ,the rest R&D  overhead,and dealer mark up.

+1 on Chang Lightspeed

Ah yes, as erik mentions above . . . I still rigidly decouple the entire deal from energized during lightning storms.  But my power issues were interstingly enough not to do with electrical storms so much as reductions in power followed by surges.  That Audioquest seems to handle them in that no damage.  That didn't happen when I first moved into this place with no protection and I had a $$ Plinius repair bill to deal with.

I've had good luck with Audioquest Niagara.  Tried many over the years (a few mentioned above . . . ) and my latest move further into a rural area has me contending with power issues 'big time'.  This unit has successfully handled them 'and' its one of very few units that doesn't affect the sound.  Had some pretty pricey products mentioned above not cut it in that sound department.

Don't know what your price range is, but I use a SurgeX sa-1810 and hear no sound degradation.  Been through many lightning storms here in FL and no damage to any components.  It isn't as pretty as the others, but it's  A-1-1 Certified - the U.S. Government's highest classification for surge protection.  No sacrificial MOV circuitry.

Here, 'A' means the product suppressed 1000 worst-case surges (6kV at up to 3kA) without performance degradation, the first '1' corresponds to the 330V protection rating class, and the second '1' means no ground contamination – no surge current dumped to ground.

Put together, A-1-1 represents the best power line surge protection certifiable under ANSI/UL 1449-rev3.

The rating that counts with SurgeX surge protectors is the one thousand 6000v surges it withstands to be "A" rated. Unlike standard surge protectors SurgeX surge protectors don't wear out due to repeated surges. 

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.

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

I like this brand power line conditioner

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

"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!

Interesting. The Panamax models seem to have an internal device that shuts off the power when there is under- or over-voltage, distinct from the feature on higher level models that work to maintain voltage when those things occur. Of course, severe spikes will shut down the power completely. 

Unless I'm reading it incorrectly, it looks like Panamax uses sacrificial circuits whereas Furman uses non-sacrificial circuits.

Panamax and Furman are owned by the same conglomerate now, so they share a lot of features.  I go with LiFT and SMP from either.

How dangerous undervoltage really depends on the connected equipment.  IMHO however it's more useful because an undervoltage is many times followed quickly by a power surge. Here in SC I've had undervoltage trip twice last year.  Once during a thunderstorm and another time during a wind storm. It's best to let your gear shutdown than to attempt to continue to function when these events happen.

Probably more than you wish to spend, but I have had very good experiences (both audio and video) with this IsoTek power bar:

EVO3 Sirius

I bought it for around $500 used.