P15 struggles


A few days ago I added a lightly used P15 to my system, and I’m really having a hard time getting it to sound good. I can hear some benefits with detail and expanded sense of space, but everything is sounding really bright and ear fatiguing, and a little flat. I’ve set the waveform to Sine, Low Distortion, used the CleanWave feature a few times, and ended up lowering the voltage all the way to 105v just to mellow the sound a bit (which does help). Input distortion is about 2.9%, and output is .1%. I’ve had the P15 on for 60 hours, and half of those playing music.

My system is a Direcstream DAC, BHK Preamp, BMC CS2 stereo amp, Focal Aria 936s. Previously I was using a Shunyata PS8 Venom/Defender combo, which was causing fewer tonal issues, and might have had a deeper/quieter black, although it was a bit more of a ragged and dirty sound.

I’m looking for any tips, insights or tweaks for how to get the P15 sounding musical and listenable in my system.


Try plugging the Amp directly into the wall and bypass the P15 and see what happens. I run my BHK 300’s out of the wall and the source and pre through the P5. That may improve the dynamics.


That’s right, I was going to suggest the same thing.


There are 2 preamps (external and amp internal) in the system, is this necessary? Shorter signal path is more desirable every time. Every component in the system will add its own signature to the sound and P15 as superior as it is, it added an undesirable footprint. Your system was on a brighter side perhaps to begin with.

There are quite few things one can do to adjust the sound to the way they like, some ways are fairly easy and others are very intrusive, like modifying equipment PSUs.

Anyway, at your own risk, few simple checks, without going into dark.
Check your mains polarity feeding the P15. P15 live wire must be live, otherwise it may not do anything as neutral wire in power plants appears to be pass through.

Mains polarity feeding your downstream equipment. Transformers in theory do not care which input is hot (live) and which is neutral, however swapping these will effect the sound, 100%. It is to do with outer/inner tranny windings. It is not uncommon for manufacturers to wire these randomly. There is a voltmeter check, suggested on one of DIY famous forums that may help to determine if mains polarity is as desired. Voltmeter is connected to chassis of individual (not connected to anything else) equipment and the ground pin of mains socket (ground must be disconnected from the equipment during the test). Then unit is powered on and voltage is noted. The mains (hot and neutral) are reversed and same measurement is taken. Lower voltage is assumed to be the correct polarity. On mine, I recall, measurements were 20V and 50V. It appeared though all my equipment was wired correctly, but one of mains plugs was reversed inside (UK style). Reversed polarity, in my experience, can give thin and lifeless reproduction.

Low level interconnects may need to be revisited.

This can go further, but it may take years of experimenting.


Thanks, I will look into the mains polarity. I think if there is an issue it has to do with the power itself, or how the amp is interacting with the P15.

As for the preamp issue, the CS2 is an integrated amp, but it doesn’t really have a preamp stage, just input switching and an output gain stage that is part of the power amp. I got the BHK in there to help the DS DAC with its lower output, and to help the CS2 with its overly dry sound. I definitely get a much better sound with the external preamp.

Interconnects are all Audioquest Colorado.

Again, I really dig the big soundstage I get with the P15, but in this system it is coming with a lot of added ear fatigue.


Sorry to hear about the ear fatigue, certainly know how it feels - robs lots of listening enjoyment, definitely something is not right. It can be caused by so many things it may be very hard to find the cause, anything from user errors to equipment properties or mismatch. Even room temperature, humidity and even your own mood can have an effect. I don’t have P15, but from reading here, everyone seems to have very positive experience, also at PS, I believe, they spend a good deal of time trying to make power plants to sound neutral and give few multiwave options to optimize to users’ setup and ears.

Quickly checked the specs of DAC (output Z 100R) and CS2 (input Z 50kR), looks ok to me. So perhaps BHK is softening things for you as it has calmer character.
Running thicker gauge multistrand copper cable to speakers will bring more body into sound. Anything silver coated, single solid core or flat strand may sound bright. Worth checking speakers are not out of phase.


I picked up on this tread due to the ear fatigue comment. I too have been struggling with this for a couple months where I never did before. You can see my system set up in my profile, but have a P5 powering my Acoustat Spectra 33’s and pair of REL S/5 subs and a P10 powering everything else. As it turns out my ear fatigue started when I switched my P5 from Multi-wave to Sine. Can’t say how or why this made a difference, but when I switched the P5 back to Multi-wave, my ear fatigue (which also aggravated my tinnitus) immediately improved. Not sure if will make a difference for you, but thought I would share


Thanks. I took your advice, and using Multiwave 1 did help a bit. Still sitting with it to see if the change is enough.


FWIW my Multiwave setting is at 4 and Phase Tune at 2.