P5: Phase Tuning???

I hope some of you will help me understand Phase Tuning. From first impressions, it appears it could be nice fine-tuning tool, but I have no idea why, or if this is specific to my power.

Even after 600 hours burnin, I had difficulty getting the spaciousness, texture and micro detail I wanted from the P5. I did finally get to a really good place, but with so many people finding power plants more plug and play, I kept wondering about wildcards like Phase Tuning. Compared to minimal conditioning before (an Uberbuss and modded Brickwall), the P5 was a breakthrough for voltage regulation, but had for me (all slight) a darkish density, hardish edges, and related micro detail limitations. I craved subtle qualities more complex micro detail can offer.

Having heard phase is a rare issue, and if all the meters display logical info…don’t mess with it, I looked more at cables, feet, room circuit noise cleaners etc. The biggest breakthrough toward more micro information was a DIY 8 gauge cable with many twisted silver on copper teflon wires of various gauges and rhodium ends. The thought again…had this done something good to the Phase.

Another breakthrough was using a Shunyata Defender for a filter in my modded Brickwall and running the tweaked Mac Mini, Tranquility DAC, and linear USB power supply through it, the Brickwall plugged into the same Furutech receptacle as the P5. Through the P5 at this point, the Tranquility is really good, but comparatively, it loses a little too much space reference, harmonics, complexity… Added up, for me, this can make the difference between very, very good sound, and a natural sense of real players in space.

Finally, with the most lively feet I have under the P5 (Synergistic Research MIGs), it was sounding really amazing with my Decware Amp and pre into the P5 and the front end into the Brickwall with Defender.

From this happy zone, with excellent stable power and sound, I have been playing a little with Phase Tuning. In this system/room, set at minus 3-4, I get a more spacious sound that is articulate, but also smooth, complex and textured, and with a nice musical warmth. One of things I work toward is resolving clear differentiation between notes and ambient trails near and far…smooth and natural transitions, the edges made sweet by complexity and spacial ambience that just goes and goes.

At the moment, the P5 meter reads 122.1V in and with it set at 119V, with the Phase at zero, the output voltage says 119.8. With the phase set at minus 4, the output voltage says 119.6V. THD in is 2.5-2.6 and out is .1 both ways.

Can anyone help me to understand this phase thing? Is there a good reason for what I am hearing? Is Phase perhaps an important tool for subtle adjustment? Is the Phase here in my house a reason for some of the difficulty I had getting the sound I needed from the P5? Or any other thoughts?

Welcome, Will

It is rare phase tuning needs to be used. It is there to adjust the P5’s software to better phase lock loop synchronize with the incoming AC in certain odd circumstances. In these few cases it helps lower the THD.

There is no harm playing with it. So try the various settings if you would like and listen for a difference.

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Thanks Elk.

It sounds like what I am hearing is outside the scope of the design intent for Phase adjustment. But since “Phase Tuning” changes software settings, even though I have no THD issues, I wonder what the software is doing in this case?

I have been playing with it too short a time to be clear about all the specific sound attributes, or even if it is a definitively useful exploration (only started today), but for fine-tuning, it looks like it could be a useful tool, shifting the tonal focus a little. On first impressions, zero seems to have excellent focus and definition, and this might be the best, but maybe not depending on tastes and system/room? At minus 4, the articulation is there, but it seems to cause my system to soften edges (more texture) and create more sense of space, shifting the ambient focus broader. Though each aspect of the ambience seems a little less defined, the whole of the spacial info seems to have a little more presence. I am thinking it feels more “atmospheric.”

I will keep exploring, but am wondering if you long term power plant users might be able to fill in some gaps for me?

Any thoughts?



I was one of the people that had a phase problem. My power company had problems and the incoming voltage had 14% THD.
The P10 could only reduce it to about 8% THD.
That was not good enough for PS Audio so they came up with the phase adjust. With that I was able to adjust for minimum output THD.
My power company has since fixed their problem but if it ever comes back I will be able to compensate with the phase adjust.

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Will said

It sounds like what I am hearing is outside the scope of the design intent for Phase adjustment. But since “Phase Tuning” changes software settings, even though I have no THD issues, I wonder what the software is doing in this case

This is an interesting question. I do not know.

My guess is that it adjust the PPL a little above and below 60HZ and its harmonics to try and line up with what the power company is producing so that the Power Plant can better do its job. But this is literally a guess.

Here is a technical explanation that PS engineering gave me while they were troubleshooting my 14% incoming distortion.

“Sounds like you have some technical background… I am varying the phase shift between the incoming voltage and the output voltage. The regenerator synchronizes with the zero crossings of the incoming voltage. However the peak of the incoming sine wave is usually not perfectly in the middle of the zero crossings, because of the phase of the distortion products. So in practical application the regenerated wave has to be shifted slightly from the input. We haven’t found a good theoretical model to optimize this, so we really appreciate you helping us get some empirical results.”

Thanks folks.

I think I get this. It sounds like the regenerator is syncing with incoming zero crossings, but the sine wave center is not necessarily centered, the wave being a little crooked with distortions. So the peaks and troughs are being shifted (ideally to center) by adjustments?

“I am varying the phase shift between the incoming voltage and the output voltage.” I wonder if this means the phase shift adjustments define the final sine wave shape, or if the wave is processed further to before output?

Though the wave is much better here (around 2.6% THD) than st50 had with 14% incoming THD, there is definitely sound change with Phase adjustments and it would make sense if it were changing the peak shape and crossing point.

Then the question for me becomes: Does the P5 definitively modify the sine wave peaks and troughs to “perfection” if the initial THD is not too haywire? Or with reasonable THD coming in, can the Phase Tuning adjustment actually be used for fine-tuning the wave further, possibly bringing it closer to a perfect wave form if we can figure out what indicates that it is better?

I have not played much more, getting a feel for minus 3 and 4. From this the THD remains .1% and the voltage a few tenths closer to the chosen setting. I can adjust all the way to -9 or plus 9 before the THD goes up from .1%. The voltage reading IN is 122.2 now. Set at 119V, with the Phase set to plus 9, the output says 120.2V. Phase at minus 9, Voltage reads 119.3V. Does this tell us anything?

At this setting, with the reduced edge hardness, and increased spaciousness, texture, and broader ambience, is shifting the phase peak adding some kind of subtle distortion other than THD??? Or is it a noise free phase shift that is allowing more micro information from the gear? And finally, do the adjustment sound changes I get here relate to those of anyone else? Or is it dependent on our exact phase coming in?

Whatever it is, I am pretty sure it has excellent potential for tuning. For example, at least in this room, at minus 3-4, saxes that can be too hard/rigid become more textural…less brass and more reed…and ambient information that seems too consolidated and isolated on zero, integrates more with the rest of the room information. At the same time, the individual player definition in the soundstage goes a little softer, though still very nicely saturated, but with more space, more in-between ambient information and better depth definition.

That said, Phase here set at zero is an excellent, solid sound.

Maybe I will get a chance to listen some on the plus side of Phase later today.

Hi Will,

You haven’t mentioned Multiwave. Have you tried it? I hear more stories about positive sound quality effects from adjustments there, than I have from phase adjustments.


Hey Dave,

I enjoy multiwave, especially on some recordings. On many though, it thickens my sound a bit much for me, so I tend to leave it off. Admittedly, I have not tried hard to make it work though, exploring it with some minor adjustments now and then. I think it is probably to do with my amp. It is a very simple point to point tube amp that is fast, rich, and lucid. Multiwave can saturate the sound too much for my tastes. Perhaps the amp tuning already takes one or more of the tube sets close to ideal limits?

Hi Will,
Stumbled on this older post of yours–we usually talk on the Decware forum or in email and hadn’t seen this.

I’m using a P15 now and it has a tuner for Phase Control and when I use it I get varying results, usually +4 or +5, now and again -1 or -2. And then when I press auto-tune again I usually get. . . 0dd. So I started playing about with Phase myself and my findings are similar to yours. At -2 or -3 I get a very atmospheric sound with a less hard edge to horns and lead piano lines, and a nice tonal balance throughout most material. I tend to leave it there these days. Going to +1, +2 or above tends to gave a solid body to the sound, a more compact and slightly forward presentation which works well with some material.

Also with the P15 I find that I use Multi-Wave a lot more than I did wth the P5 and even the P10, where I did use it a bit more. Every little adjustment on the P15 is a bit more noticeable and profound than the previous power plants I had. It’s nice. . . and also like tube-rolling a bit frustrating at times. But options are nice!

I’ve figured out that my P15 seems too like it best when I have the MW Strength on 4 and the Phase Tune on -2
At least my ears are most happy with my P15 with those settings even if isn’t THAT big of a difference.

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Sorry for my late reply Lonson.

I have not been here for a long time, so not looking for notifications. This one sat in the spam folder for a while, then I kept forgetting. So sorry about that.

I am glad to hear phase tuning is working for you, and you too Birger. It remains a primary tool for me. My system and room tend a bit toward bass in the balance, and pretty substantial resolution and density throughout. So with the “stock” P5 sound weighing toward warm and less revealing than I like, minus phase and minus voltage adjustments really help me get sound I find natural and alive.

After having done all I could toward more resolving and spacious sound with cable, fuse, feet, passive filters, finding voltage and phase adjustments, I have been able to get what is to me a less colored and masked sound than I originally got from the P5. Tuned more-or-less to my system and room now, with more sense of liveness and transparency from the P5, I no longer hear masking or coloration except by direct comparison to my front end filtering setup. I still prefer my modified Brickwall with a Shunyata Defender for transparently powering my computer and other source components, but especially needing voltage regulation in my house, for my amps and everything else, I am quite happy with the P5 once tuned.

My modified Decware Torii IV tube amp, and CSP3 pre, being simple and revealing, my sound balance is sensitive to voltage changes, and this is the reason I got a P5 to begin with, my house voltage being irregular and high in general. Here, high voltage equals a more dense and full sound, and lower, leaner, more open and spacious. For me, the added benefit to regulated voltage with the P5 was realizing how voltage adjustments are a great tuning tool also. If the sound from tube choices is weighing toward heavy and dark, but otherwise compelling, I might experiment with dropping the voltage setting a bit. Or too lean, I can raise the voltage. Though preferring neutral/revealing tubes, cables, etc as a base, I rarely change it anymore, but if I do, it is by only 1 volt, and that matters here. Typically I like the voltage at 118.

Also, in my setup, the minus phase adjustments enhance the sound balance nicely. Now I hear the negative phase adjustments as opening space within, relaxing the concentration of what came off more as macro detail into micro and very fine detail in space. Effectively the right balance of P5 settings help give me more fine resolution and spaciousness, making the sound experience more “real.” Harder edges become less edgy, “feathered” by more very fine “particles” of detail in space. Ambient trails and spaces between players become more present, while increasing nuance and timbral realism makes the players more “alive,” .

My P5 phase setting has been -5 for quite a long time, but recently, as my system becomes more resolving of complexity and density, I like -7 as well. I don’t know if my house power phase is off or not, but I much prefer the more open sound in my system/room from this setting, bringing out nuance and natural beauty from more complexity and space. It sounds fine with the phase set at 0, but it becomes “alive” with “the right” settings.

With your P15s, beyond more or less atmosphere and complexity, or density with off-zero phase changes, do you noticed a difference between the odd numbers and even? Not necessarily better or worse, here, I personally alway come back to the spaciousness I get from odd settings. Mostly I seem to end up at 119 or 118V, high regulation, -5 or -7 phase, and no multiwave….but trying minus 6 just now, listening to Heather Masse, Many Moons, the more solid/forward mid-note feel is really nice compared to the generally more airy/spacious feel of -5 or -7. But finally, each time I try it, comparatively, I find even settings a little overstated in my setting.

Great tools these adjustments!


Thanks for the reply Will. Interesting find about the even and negative number differences. . . .

I confess that I haven’t really explored the phase settings as broadly as I should. It puzzles me that when I hit “Autotune” the P15 tunes to +4 to +6. I often leave that going and listen and it sounds okay but becomes annoying with a bit of time, too dense and with an abrasive quality. I do like the settings at -1 or -2. A little mellower of a presentation. For the most part, as I have been playing with other things instead (mostly 6SN7 tubes with converter bases and different voltage regulation and rectifiers, and also exploring a revisit to some voluminous artists’ works that I have gotten wrapped up in) I have left the phase at 0 for the most part. I’ll have to try -5 to -7 soon and see what transpires.

What has most surprised me about the P15 is that I like Multi-wave on in the system, as high as 3 or 4. I think this gives the music a more “analog” feel or a sound that brings me back to my pre-digital systems’ presentation, from before I became an obsessed listener to the system itself. . . .

And with the tube complements I use and the P15 settings I usually have the voltage at 120 or 121. . . I like to thicken up the sound a bit. … makes it seem more realistic to me at my listening distance.

THANKS for the comments, you’ve given me things to process and experiment with.


Hi will thanks for sharing your findings…

Try running clean wave press the clean button twice to let a full 60 sec run…
in my system it freshens and liven things up …

If you haven’t yet give it a shot…

Happy trails

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Will as far as phase tunning…my incoming thd has gone from 2% to 4-5% in the
past couple of years or so…phase tuning took about a minute for the system
to calculate and apply the results. Outgoing thd .1%-2%…

My system has really benefited with my regenerator.

Lonson and davida,

Yes, individual power and system/rooms do seem to consistently define the particulars of what we each need to “get there,” but the basic tendencies of the tools of the regenerator appear to offer similar results. So though chosen settings will vary, how they work set higher or lower appears to do similar things across systems. Here, it is a real boon to immersion in the music to get the power “just so,” and having these relatively fine adjustments are quite useful tools for me.

Interesting… It sounds like your newer regenerators have a selection for self phase tuning based on how the P15 interprets your power. Also interesting Lon, that you don’t prefer the results from the auto tune, but you do like multiwave more with the the P15 than with the P5. It is good to hear PSAudio keeps improving their regenerator tech!

davida… I like the clean button for a 60 second cycle too. In a too-quick initial glance at your post via email, I “imagined” you were saying to run the whole cycle twice rather than hitting the button twice to get one full cycle. Got me thinking this may not have been a bad mistake though, and I will give two clean runs of 60 seconds in a row a try now!

My THD, as displayed on the regenerator, has been steadily rising over years too, but rarely much above 3. Getting a balanced transformer from a Chinese seller that looked like it used pretty good parts, I decided to try some nice caps in it, and a good fuse and cable, and see what it did before the P5. After some cap adjustments, it seemed to have become a slight sonic benefit, a little more solid and refined, though I need to more carefully AB it now that it is all burned in.

It was speced for 115 volts, and the voltage-in on the P5 starts 2-3 volts lower now than without the transformer in front, now usually around 119-120 or a little more. With it, THD-in on the P5 stays around 3.1, generally a little higher than without, but the P5 THD-out stays around .1-.2. I mention the transformer for accuracy, as I am using it for now. Not sure how it effects the P5, though I would think that starting at a voltage that is closer to my goal might work the P5 a little less in that capacity.

As to our regenerator adjustments though, I have noticed interesting phase/voltage relationships before the balanced transformer and after… The P5 set at 118 volts, with 0 phase setting, testing today, the out-voltage reads at 118.5. Still set at 118 volts, phase at -5, voltage out=118.2/3. And at -7 phase, voltage-out=118.1. I don’t know how accurate these readings are, or if this voltage correction is the result of a truer phase correction, but observing this phenomena as I initially experimented did cause me to go further and further out away from zero, finally learning I liked the phase at -5 or -7.

Today’s tests, the THD out remained .1-.2, but it does seem to stay more on .1 than .2 at -7 phase where the voltage is also closest to the setting of 118.


Will, bravo for you tinkering with the various tool settings
exploring what these can accomplish for you…great leaarning
to be had here…

As for running clean wave 2x for 60 sec each …is what I was hoping
to convey…The credit goes to sixpack1 who ran his 5x at 60 sec each run.

Here is the thread…great reading…

Thanks for the clarification davida, and for the link. Interesting. I usually run cleanwave for one cycle every several days. I will try 5 cycles in a row, and then experiment with using it more often and for more than one cycle.

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I really hope doing so will make a difference for you…if not
no worries you gave it a go…

Something else that I have read and tried is to power the regenerator off
then turn the power switch on the back to off…kind of like rebooting the
computer as a fresh reloading of the software to the cpu takes place…

This seems to freshen things up…

Happy trails

I’ve done some experimenting late last night and early this morning and I think I DO prefer a negative odd value to an even one.

I find that I like the negative phase IF I lower or defeat MultiWave. MultiWave at 3 or 4 gets me a very similar sound to -5 in Sine, and MultiWave at 1 with phase at -5 is quite nice, both widening and deepening the soundstage compared to 0 and MultiWave at 3 or 4, which has a similar frequency balance and image body. But has a slightly more open presentation, with 0 and MultiWave at 3 or 4 things seem a bit more compressed.

So I’ll leave it at -5, MultWave 1 for a spell as I listen to some newly remastered Coltrane cds from Japan.

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