Power Conditioners

Expectation bias leads a lot of people to think they hear an improvement when in reality there is no difference. The question is, is a perceived improvement as valuable as a real one. My own attitude is absolutely not. 
I tend to ignore subjective evaluations and look for objective evidence such a lower signal to noise ratio. Obviously object evidence does not tell the whole story especially with amps and speakers. These evaluations you have to make on your own.

Okay high-amp you asked so I will tell you how it is. There is no such thing as "power conditioners". At least not in the way you mean it. A power conditioner is not some generic fungible commodity like corn or crude oil. Although come to think of it even crude oil is not all the same, with "sweet crude" commanding the higher prices.   

Got it? You can't make sweeping broad statements without being clear to set some ground rules or conditions. Questions about "power conditioners" without that are meaningless to the point no one even knows what it means. Some are mere transformers. Some include caps, and the varieties and combinations go on and on and on.

Some are a complete waste of time and money. Some are transformative to the point you will be shaking your head and start blathering about how you have discovered the most important component of all: the power conditioner!

This will last until you hear a really awesome speaker cable, at which point move over power conditioner. Spoiler alert: its like that with everything. Sorry. But you can forget about "power conditioners". All you can do is look for one particular component that maybe happens to be a power conditioner, and do it on the basis of how it sounds. Same as everything else. Don't make the rules, just report em. And that's the way it is.

I had a PS Audio line conditioner and, yes, stuff sounded fine when I had my components plugged into it. One day about two or three years in, though, the thing heated up and started to smell bad.  I hurriedly replaced it with a generic power strip. Sound quality might have taken a one percent hit.  Short story shorter -- I happily use the generic strip.  Yes it is plugged into a High End wall socket, and my DAC is plugged into it's own dedicated High End wall socket, but AC quality is something I don't obsess over anymore.  Finally, oh yeah, I do still have the boa constrictor-width AC cord that came with the conditioner.  It goes between the generic power strip and my integrated amp.

Power conditioners are electronics parts, they can protect against surge, and soundwise they are suppose to clean the line but it is half truth, they add a noise of their own, this is a trade off with some lost always in the final result...

I own one to protect my amp against surge but i improve the sound greatly adding my own creation, the"golden plate", on it and isolating it from the floor...

golden plate: shungite +copper tape on the external side.....

I don't use 'em. No surge suppressing strips, or regenerative power. Just pure juice from the one 8 gauge line.