PS Audio Power Plant 15........

Been using many iterations of PS regenerators since late ‘90s, their PP1200 (20yrs+) trouble free (only needing fan changed twice), always brought improvements to whatever plugged in (various—too many to list over those years).

Recently, just for peace of mind sake~thinking too old (but they still work flawlessly btw.)—while looking for new, auditioned some of those mentioned above plus few other popular auto voltage regulator types. Again, ended up with P20 clear winner in my system. 3D, resolute, dynamic all the while sounding v.natural/organic ie.no stripping/washing off colors as many do. And that saying with my main (dedicated) started reasonably ok—with less than 1,5% THD in on average, and very little voltage irregularities if any.

If sure not a faulty P15 you got—I’d try let it settle a bit more whilst try play around with adjustments. Sine/multi, also—tune voltage out—as few volts up/down could alter sound quite markedly ime. Also, power cords into/outward of it play a big role too. And if possible, separate power amp from sources on different dedicated mains using two PP (even smaller ones ie. 2xP10), this will further bring upticks in sound—cleaner, better separation and open up the soundstage even more, imo.
Can’t imagine living without them in my system. Good luck.

I recently added a PS Audio Stellar Power Plant 3, and I'm astonished with the improvement in sound. Much bigger soundstage, better dynamics and separation, a just-right smoothness and ease to the music. Note decays ring on and on. I knew that the AC here in my old Chicago building was pretty bad, but I didn't expect clean power would make such a big difference. I'm sorry you aren't hearing an improvement. If it doesn't improve with some more time, I would try another unit, if possible. Good luck.

bbenzaquen6343,  I know this is ancient history but what did you finally do?

I find ANY AC filtering or regeneration whatever, negatively affects my AMPLIFIERS so I only use them on sources.  Most of my turntables come with

speed controllers that regenerate ac internally and IMO need no addtiional ac prep. All the ac filtering and regen devices have 

high current amplifier outputs but again I prefer not to use them.  I am a rural

listener and dips in ac levels are the predominant issue here.  The ac lines to my primary system are dedicated back to the panel box.  

I found that my P15 made all of my low powered gear sound great but cannot handle a high powered SS amp. It killed the dynamics when using with my old Coda #16. Plug directly to the wall and get a dedicated line from the panel if you can. It made all the difference for me.