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

I can’t imagine what’s going on. The P15 has brought great improvement to my system.

horses for courses.
I believe it’s safe to say that different products and methods, perhaps especially in mains conditioning, in different locations (geographically on the grid) and in the context of a system (a whole kit in a room), offer different results more then not.
So nothing about this is simply black or white. It is a more wholistic thing then that.
One can believe whatever they would like about a particular product or product line but it’s relatively meaningless without Listening, in a context, over time to become understandable. And then, that is only one context.
I’ve literally taken the same kit to a different location and room and had to dance to a completely different tune. The nature of a perfectionist hobby.
That said, i’m sorry that the PS Audio isn’t working out for you. I have had great success with other components in their earlier product line and have yet to hear the Audioquest Niagara in a system that I understand. Conversely, I have a dear friend who’s kit sound I favor, who returned a Niagara for other solutions. Go figure.

Forgive me as I may be preaching to the choir here but have you given it time to settle in as big things like that can take a fair time. I would recommend at least a couple of hundred hours. 

I agree with jim204. Give it a week of active use so it can settle down in the system. I once purchased a conditioner that sounded quite terrible in my system for the first three days, and on the fourth day, it suddenly changed and started sounding fantastic. It was a used unit, with plenty of time on it.

Totally agree with the above.  Leave it in your system for at least a week and then switch back to the Niagara.  Then you'll know.  Then again, if regenerators were the cat's ass, why isn't everyone using them?  So your initial conclusion may well be on the money. 

For those who suggest a "settle in" period, thanks -- that's good to know. I've heard that with other things like cables, interconnects, etc. It's not clear to me where those elements are "burning in" or "settling" (as the lingo goes) vs. the other factor -- our ears getting used to a new setup. Indeed, it seems nigh impossible to disambiguate which is "us" and which is "the gear."

In a way, that's a problem, because we don't want to pay big $$ to get used to something that isn't really changing.

On the other hand, if the final experience is better, who cares? Better is better. (Of course, we're left with a question....)

The Power Plant thing is like any other piece of equipment- YMMV. Subjective "improvement".

I  instantly heard the opposite when I plugged a Power Plant in years ago. My 13 year old, PP Premier was recently refreshed by PS Audio and will go at least another 10 years. Best purchase I've made here on Agon.

I plug everything(including amp)into it with great results. 

I went from a Niagara 1200 to PS Audio P12 and the difference was stunningly improved.  I'm almost wondering if the OP is finding some levels of incoming THD euphonic in his system.  The P12 dropped incoming THD levels from 4% to 0.1% in my system.  The background became deeply black and quiet, particularly impactful with all my tube gear.

I can’t imagine what’s going on. The P15 has brought great improvement to my system too, especially with the performance of the DACs I have connected to it.

Break in... ? the op said it was a dealer demo, so it probably has many hours of playing time. But, it may need time to settle in its new environment. (perhaps a few hours).

I owned many iterations of PS Audio power conditioners, when I switched to the Niagara 7000 it was leap years better than PS Audio. Especially the fact that amps can be plugged into the Niagara! I now own in addition to the Niagara 7000 a 1200 that I use with my JL Subs and a 1000 that I use with my home theater equipment.

ozzy

It could be that the P15 has a bad resistor or cap or some component that is limiting its capability.  Perhaps get another one and try it in the same system?  

Do you have a top quality power cord to connect the P15 to your home service?

If it’s a demo unit, it probably has already been broken in unless the dealer told you it wasn’t on the floor very long.
If it’s that far off, call ps audio about your issue. It should be under warranty and they are very good at supporting their customers 

Could be  the Pass amp just doesn’t like any power conditioners with active devices. 

The final word on any piece of gear, of course, is how it sounds TO YOU. Don't convince yourself something must sound better simply because of price or name recognition. That said, I'm a regular watcher of hi-fi reviewer Steve Guttenberg's YouTube channel, and I remember being startled when he said that he tried a PS Audio regenerator once, and it clearly, without question, worsened the sound quality. (Who knows why?) He ended up getting rid of it. Guttenberg is a huge Pass fan, and has a Pass amp in his current system, though I don't know if he had one when he tried the regenerator. I also remember stumbling across a comment on a hi-fi forum (maybe this one) in which someone said that Nelson Pass once said that using Pass amps with other power components (he might have specifically referenced PS Audio regenerators) is often not a good idea, because the power section in Pass amps is already so good that most other power components will be inevitably be a downgrade. That might not be the exact way it was put, but it was something very close.

How does clean power worsen the sound?

That’s what happened in my system as well....ruined all nuance, air, 3 dimensionality, etc. All systems are different...in mine not good. (All Ayre)

I purchased BHK preamp, M1200, and P15 together three weeks ago. The first week they sounded flat and dull, but now they are phenomenal. It may well be PS Audio designed their gears to match well with their power plants. P15 may not give as much improvement to other brands as to their own.

Another huge improvement was adding an Audioquest Thunder AC cord to P15. It made a dramatic improvement too.

I think “huge” is an overstatement. I had a Pass Int250 with a dCS and in my opinion there were some subtle improvements - PS Audio gives you a more rounded sound and a blacker background but I can understand why in some systems the leaner sound  without a PP would be preferred / work better. 

@hilde45

+1

To the OP,  If you haven't already tried this I would as a test only plug source components in to the PP.  Leave the amp out, then if no improvement plug it all into the wall (no conditioner at all).  Also, go back to the dealer and have them plug it into a system and notice the change if any.  Good luck.

I would send it to PS Audio for Eval.You should be enjoying the upgrade

If you think that it is going to sound great out of the box...it's not.  I leave mine on 24/7 and as I recall it took a good 10 days to settle in.  Initially I freaked out because it sounded worse than when connected to the wall socket...but now it's simply incredible.  If after the break in period it still sounds bad...then I would contact the dealer.

PS Audio has a 30-day 100% refund return policy. Send it back if you’re not happy. Easy solution.

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.