Who Tried Power Conditioners Over The Years and No Longer Use Them Today, Any Why?

That would be me.

Although I do not live a condo type building and do have dedicated

power.

From what I can discern, AQuest Niagra and Shunyata are the top

contenders if you need one.

In this whole argument, no one talks of the quality of the power supply in the amp.  A well-designed power supply will do a lot of signal conditioning.

I didn't have the experience the OP asked about - rather I'm having the exact opposite experience. A couple months ago my PS Audio PowerPlant 15 quit initializing.  I didn't think I missed it that much but since I got it back on Tuesday I have not been able to stop listening. It sounds so so good - more space between instruments, better soundstage, fuller tones. 
 

PS Audio wasn't forthcoming about what was wrong with the unit but it was repaired under warranty. I was told it was "upgraded to that latest Rev “B1”" without further detail.  I won't be ditching my regenerator anytime soon. 
 

Matt

I think some of the difference in experience may be attributable to the quality of the "unconditioned" or dirty power. I don’t use any line conditioners on my main system except that the 10kVa isolation transformer on which the system depends has a surge protection board. And I have a basic, "whole house" surge protector.

I have used various aftermarket surge protector power conditioners over the years and though my experience may be dated, found that they all altered the sound. To the extent of throwing "baby out with bathwater" I concluded that the conditioners I tried at that time were compromising the sound, but I could see instances where a conditioner might improve the sound of the "dirty power."

PS> I listened to the system without the iso transformer for almost two months before it was installed, and though a little "bright" at first--burn in?- the addition of the iso transformer did not change the voice of the system. I think the infrastructure where  I am near downtown Austin is far newer than that which I had in NY metro. So, I’m not sure that there is a universal conclusion applicable to alll systems. What’s your power like out of the wall? And what can you do to improve the quality just using. basic best practices, without voodoo. That’s where I’d start, before adding any black boxes (of which I have plenty).

Reading through all this suggests to me that we all have different power cleaning needs depending on what comes into the house and our HiFi equipment choices.

In my case with dedicated 20 amp line, all top end C-J tube equipment and dCS front end, an AQ N5000 made no difference vs. a 20 yr old Shunyata Hydra 8.  Then I tried a new Shunyata Denali 2 with good result.  Still using the great AQ Hurricane cables.  The C-J class A amp still goes directly to the wall however.  One nice change was to to isolate all the digital power supplies, Roon Core etc. into a separate Transparent power strip, still pluged into the 20 amp outlet.  Now all is quiet and dynamic..