P12 noise or silent?

I have got the P12 setup finally.

I plugged all my preamp, power amp, TV, player, subwoofer etc…the sound stage is wider, more dynamic, and AV dialog is more at the front stage.
And it’s only using 30% !

However, I hear a consistent ‘deee’ sound from P12, while I turn on any Zone. That deee sound seems to be a transformer working at high frequency or whatever. I can hear it easily even I sit on my sofa about 9ft away.
It became silent if I turn off all zone. (Just a very low noise from the P12 itself)

As P12 user, are you able to hear any noise when the device is on (and zones are off), or when all zone are on ?


I have a P12 and a P5. They run silent.

I think they are hum from the P12 transformer.
I will call the dealer and change a new one .

Well, that was easy!

Changed a new one, was testing in dealers shop, the new unit has even bigger noise. I refused to take the new one.
Paul, is it normal that it has so many faulty unit?
This is from Hong Kong.

Problem solved.
Finally get a new unit working as dead client .
No more noise.

How many did you try before you got a good one?

The third one…
First one has noise only when zone is on with supply.
Second one has noise even when no zone is connected.
Third one is dead silent…
All are newly open from box, so I am sure it’s all source from PS audio directly.
I hope @Paul would take a look and make sure the supply to Hong Kong has better QC before shipment.


Sometimes I wonder if they get checked at the factory at all (because I’ve received many brand new PS products that had a fault of some sort).

This is my first PS audio product, and to be honest it push me away a bit having this experience. I wanted to get refund if the third unit is not working.
Luckily the dealer in Hong Kong has helped a lot and they do swap a brand new unit for me to make sure I am happy with it.
However, I am wondering how could we avoid such issue again in the next purchase from PS Audio.

Don’t worry about it. If your next product is faulty just swap it for another new one.

I wonder what inside the P12 is being upset enough to make that noise? It has nothing to do with QC as I am certain each of the P12s in Radar’s stock would pass our QC testing and are built to the same standards. My guess is that the one you got that was silent has less noise on one of the capacitors or other passive component that is somehow unhappy with something in your home’s AC.

I am glad you found one that works for you. This is an issue that’s not come up before and I wonder what in your home’s AC causes the others to make that noise. If we knew then it might be possible to specify a different part so it wouldn’t resonate like that.

As it is you found one and while that’s a big pain in the butt, I am glad you found one. Thanks for letting us know and we’ll keep our eyes out for anything similar or clues to what might be causing that.

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Brodric, why would you write something like that? Does it make you feel better lashing out like that?

Seriously? Every product goes through a battery of tests and burn in before ever getting out the door and you know that.

Paul, have you ever discussed with your distributors having them check local power for unusual noise? I say this since it seems most of the issues with noisy components come from countries that do not use 120VAC/60 Hz. I have no clue if their power is the same/better/worse, but since you have to synthesize that power in Boulder, perhaps there are issues you can’t experience during the QC process. From personal expereince I know that transformers can be noisy from poor power. It comes and goes so I consider it out of PS Audio’s control, but if there are worse problems in other countries maybe something more is needed. Just a thought …

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Yes I think pmotz is correct about country testing.
Since this is not just in my home ,but also in dealer demo room .
First, I ordered P12 and delivered to my home, it has noise.
Then I go to dealer demo room in person, test it with his AC outlet and equipment, same noise. Then they offer a replacement.
Second day, new unit comes, I go to dealer shop again, and test the unit on site, however the noise is worse, as I said it didn’t even turn on any Zone yet. So it obviously need to replace another one.
The next day, I got call from dealer new unit is ready, I told them please test it by themselves first before deliver to me, make sure it’s silent. And they did , and soon the unit is in my home. I turn it on, silent, great! Then plug in my equipment, turn on zone, also silent.
I have been using it for 2days now, it runs silent so far, so I am happy with it.

So I am sure it has nothing to do with just my home AC quality, because the same issue happen in dealer shop.

In Hong Kong, the standard is 220V/50hz, Some place might have 230V variation. From P12, my home is 229.1V, and in dealer is about 228V. My THD input is only about 1.1%.

I wished this product works for any input as designed. So I didn’t expect to have noise, so do the dealer told me.

If this is not QC issue, may be we need another battery test in different country?


Unfortunately I have the same case here!

It drove me crazy about the noise coming from p12.

My case is that I used my p12 happily in the past eight months until I recently purchased my CH precision C1.1 and D1.1.

When I plugged my C1.1 into the p12, there is a “zee” sound coming from P12 which is loud enough to be heard in over 10 feets. The noise is having a high frequency. It will disappear when I turn my c1.1 off.

Definitely this is because of some resonance inside the P12 as said by the CEO above.

However, I have no luck as the user above that Rader requested me to send back my P12 for their checking, instead of replace a new one for me. My question is that the P12 is not creating any noise itself without plugging my dac. What is it for sending it back to rader without my equipment? Or do I need to send it back with my whole system for checking?

Last but not least, the checking needs to take over 2 weeks of time, such that my whole system have to be shutdown for two weeks.

Does it sound like transformer noise or possibly the fans spinning?

Must not be the fan noise.

The noise stops when I switched off the dac.

How come a device that aim to reduce the signal noise become the one emit high frequency noise itself.

I accidentally found this forum and this post when I’m looking for solution from internet (it is quite impossible to send it back to the dealer for two weeks of time without any temporary replacement as this is the power plant which supply the power to all my equipment!).

I just had a quick discussion with one of our tech support guys and he’s pretty confident he knows what could be producing the noise. There can be some odd interactions with transformers and downstream gear. Email Mark at marks@psaudio.com he works with a lot of our international distributors, and will be able to get the proper parts sent for getting this fixed. It will help him a lot of you email him the serial number of your P12.

Thanks jamesh