PS Audio DirectStream Power Plant 20 AC regenerator Page 2

The P20's touchscreen display is large. The menu's most comprehensive screen shows four meters, indicating the power being used by connected devices, the total harmonic distortion in the incoming waveform (currently about 3.5% in my system) and in the outgoing waveforms (currently an impressive 0.2%), as well as an Improvement Factor, which I presume is the ratio of those two numbers.

Let's not forget that the P20 doesn't just improve the quality of the power your system sees; it also protects your system from destructive electrical power, such as voltage surges. The owner's manual claims "energy dissipation" of 2040 joules, which is pretty standard for a high-capacity surge protector, and a "peak current surge" of 180,000A, which is much higher than any plug-in surge protector I've ever seen. Myers, the PS Audio engineer, says that "all three [models] include heavy-duty metal-oxide varistors (MOVs) that provide exceptional levels of surge protection. The number of MOVs increases as the capacity of the regenerator increases: the P12 has three MOVs, the P15 has four, and the P20 has six."

On the one hand, it's necessary to protect my expensive stereo equipment from power surges; on the other hand, I don't want cheap, crappy surge protectors compromising my sound. Ten thousand bucks is a lot to pay for a surge protector, but if it protects my equipment without harm—if it actually makes the music sound better—that's not a bad value proposition. But did it?

I've used my PerfectWave P10 Power Plant continuously ever since I reviewed it for the May 2016 issue. I noted then that, with the P10 feeding all my equipment, "the aural images reproduced from digital sources" were "fleshier, more corporeal, and better located in space." I also wrote that with the P10, the sound "seemed more natural and less electronic—almost suggesting a physical rather than electronic playback medium . . . a wood block sounded like a wood block, not a recording of a wood block."


Once I'd muscled the DirectStream Power Plant 20 into place, I moved over all the power cords from my P10, then forgot about power several weeks—I just listened to music and focused on other reviews. When it came time to get serious about reviewing the P20, I got out my Wiremold L10320—a simple, well-constructed, well-regarded power strip—so I'd be able to make comparisons.

With all the cords still plugged into the P20, I listened to "An die Hoffnung," Op.94, from a recital of Beethoven songs by baritone Stephan Genz, accompanied by pianist Roger Vignoles (CD, Hyperion CDA67055). For modern, rock'n'roll ears, lieder are a bit of an acquired taste, but I've acquired it. This is a great CD, well recorded, and Genz has one of the best baritones I know. I noted the texture, character, and expressiveness of his voice in all the quiet passages—how it often changes character several times, even within a single sung syllable. I went back and listened to those quiet passages twice more, focusing on the quality of the voice, that well-captured vocal expressiveness.

I powered down the DAC, unplugged it, and plugged it into just the Wiremold power strip. Amps, preamp, server—everything else—remained plugged into the P20. I gave the DAC a few minutes to warm back up—it wasn't off for more than a couple of minutes—then listened to those passages again.

The change was astonishing—one of the bigger changes I've heard when switching out components (loudspeakers excepted), and easily larger than the differences I heard the last time I compared two preamps. With the DAC plugged into the Wiremold power strip, a good bit of Genz's texture and character simply vanished.

A hazard of comparative listening is that what we hear is greatly influenced by our attention. When you direct your attention toward one aspect of the sound, what you hear changes. Yes, you hear a change, but what has changed is how you're listening, not the pressure waves reaching your eardrums.

A very useful technique, then, is to listen for something that goes away. When I played "An die Hoffnung" with the DAC plugged into the P20, my attention was drawn to the richness of Genz's well-recorded voice. When I plugged the DAC into the power strip, I directed my attention toward that particular aspect of his sound. I found much of it missing. That, to me, is a definitive result.


I continued to move plugs from the P20 to the power strip: preamp next, then monoblocks. There were additional, cumulative changes in the sound: moving the preamp over shrank the soundstage, and moving the amps over muddied the bass. But I noticed a difference most when I moved the preamp from the strip back to the P20—the soundstage expanded, especially in depth, and aural images were a little more precise. But no change was nearly as important as the difference I'd heard when I removed the DAC from the P20.

Before you place your order with PS Audio, think hard about which Power Plant to buy: You may need more power than you think. Amplifiers use far more power than, probably, all your other components combined—you may be surprised how much. As I've already mentioned, my PS Audio BHK 300 monoblocks consume about twice as much energy as they deliver. Pass Laboratories' XA60.8 class-A monoblocks, which I also have on hand, are specified as each putting out 60W while at all times consuming about 300W, no matter how loudly or softly the music is playing.

How does the DirectStream Power Plant 20 compare, sonically, to the P10 Power Plant? I don't mention it above, but I did do some comparative listening. The P20 sounded noticeably better, in all the same ways: naturalness, detail, image precision, soundstage depth and width. Enough better to justify an upgrade? I haven't decided.

And it doesn't matter what I think. A hazard in writing audio reviews is that different people hear different things due to differences in rooms, systems, hearing, and how (and how well) they listen. A hazard with writing reviews of AC treatment devices is that some people start out with better AC power than others. That's why PS Audio's 30-day free trial is so useful. You can try it yourself, compare it with other power-conditioning devices, and decide how much value it offers you. PSA even pays the return shipping.

I've come to consider my PerfectWave P10 Power Plant an essential reviewing tool, less because of the improvement it makes in the sound—although that is, of course, important—than because it levels the playing field for the equipment I review, ensuring the same, high-quality power for all the components I compare. There's much to be said for those magical late-night listening sessions when everything sounds magical, in part because the AC supply is quiet. Assuming it's powerful enough and doesn't limit current, a well-designed AC regenerator can provide the same quality of sound all the time. As for all the other reasons that late-night music can sound so good—solitude, scotch, bourbon, tranquil thoughts, etc.—you're on your own.

PS Audio
4865 Sterling Drive
Boulder, CO 80301
(720) 406-8946

volvic's picture

Yes, you can run out with only 10 outlets, by my count I would need at least 14. With one of these you could control the frequency of current going to your TD-124 and keep it nice and steady at 33.4 rpm. I wonder if my 40 year old outlets would suffice for one or would I need a complete re-wire to make something like this financially viable. Great products.

Long-time listener's picture

Another reason late-night listening sounds better than daytime listening is that our hearing is sharper at night--we hear more texture, color, and detail. Evolution (or a higher power, depending on your point of view) has equipped us with hearing that that becomes more sensitive during hours of darkness, peaking at about 3:00 in the morning.

I used to have a PS Audio Power Plant ('Premier,' I think). I loved what it did for my DAC, but it broke down constantly and I got tired of taking it in to be fixed, so one day I left it out with the trash.

Best regards, LTL

Bogolu Haranath's picture

It may also be due to something to do with the different kinds of 'electromagnetic' radiation the Sun emits during the day light hours ........ Some are invisible and can penetrate everything .......... During the night time they are markedly reduced and/or not there ..........

Wonder how audio systems would sound inside NORAD mountain complex? :-) ............

May be a 'higher power' is affecting our hearing :-) ..............

MvC's picture

I don't agree with the 'level playing field' argument. An important quality in an audio component is it's rejection of mains noise. A really good amp should not be affected by mains quality at all, or at least as little as possible. By ignoring this important property your reviews will be less relevant for real world audiophiles, not more.
Anyway, for most of us the question is not how much difference it makes, but how much difference compared to investing the same amount of money in your system.

dumbo's picture

It seems each company with the release of each new product tries to out due their competitors previous obscene price for a similar product. I fear there will be no end!

Anyway, I've yet to find any power conditioner, no matter how big/fancy, that did nothing but damage to the sound of any amp that it was feeding. Less demanding source gear, well that's a different ball of wax and there are plenty of gains to be discovered there by using power cleansing devices.

There is obviously a trade-off involved with these products. One must choose having protection or unrestrained dynamics/power. You cant have both! Spending $10K on a product that touts the ability to run one's whole system without compromise seems damn silly to me. Its like shooting yourself in the foot

Amps Goto Wall Directly
Source Components Goto Power Conditioners
The End :)