P5 Transformer buzzing

My new P5 power plant has constant transformer buzz. The hifi sounds very harsh plugged into the power plant but the stats from the power plant are good. I live in the UK and the voltage is quite consistent. The thd in goes from about 2.0 down to 1.7% and the thd out has never moved from 0.1%. But the sound from the hifi is brutally harsh in the treble range.

Anyone noticed a constant buzz from their power plant transformer?

There is a low buz sometimes comming from the side with the transformer. It is very low though although you can hear it from few feet away in a quite room. I have two P5 running and they both do,it.

Now as for the sound have you tried the new firmware or old ones. Also the multi wave. Nothing I have tried ever made the sound bad or Even close to what you describe . But some devices do improve more than others.

List what equipment yup,use and how.


Hi Al,

I’ve downloaded the new firmware and tried the multi wave settings. Makes little difference. The P5 does improve the sound quality when compared to just plugging straight into the wall socket but the improvement is only a slight one. My equipment:

Turntable, Pink Triangle Tarantella, with upgraded power supply, moth arm, Ortofon 2M bronze cartridge

NAD C545BEE cd player

Cyrus 6A integrated amplifier

Harbeth P3ESR speakers

various Russ Andrews woven interconnects and power leads

The purchase of the P5 was my latest and final attempt to defeat the noise inherent in our mains supply.

I have tried just having the cd player, amp and speakers connected or just the turntable, amp and speakers connected.

I also have a PS Audio P300 power plant. Although the fan noise is much louder the sound quality is far better than with the P5: much better depth, three dimensional sound, less harsh, but still harsh.

I also have a Ben Duncan balanced mains unit. Hums like mad when plugged in. Have used it instead of P300. Sound is detailed, can still be quite hard. But the hum from the transformer in the balanced mains unit is so loud its not worth using

I have various Russ Andrews passive mains filters that do little to increase my listening pleasure.

The two best mains accessories I’ve purchased have been the P300 and the P5 in that order. Just like all the other mains accessories I’ve purchased they do improve on the sound compared to just plugging straight into the wall. But just like other mains products I find the sound quality is still dependant on the quality of the power coming from the wall socket.

When the power out of the wall socket is at its very best (on those very rare occasions) and my hifi is plugged directly into the wall socket I think the hifi sounds much better than when the power out of the wall is not at its best and the hifi is plugged into the P300 or the P5.

So, in my opinion, just as with all those other hifi accessories to my ears, even with the P300 or the P5 connected, my hifi is still a slave to the quality of the power coming out of the wall socket.

Its very frustrating to have spent three to four thousand pounds on hifi, let alone accessories and feel that the best option when I want to listen to relaxing music is to listen to my Ipod.

I listen to my hifi rarely, usually not even to a whole album before I wander away, despondent to do something else.

I’ve taken all my equipment back to the hifi shop which is about 50 miles away to test how the hifi sounds there. It sounds great there. Better mains power: less polluted, less RFI, less DC in the mains.

I carted it all back home again. Tried it in every room of the house but it sounds harsh again.

Whatever the power line noise is in my area, it kills the hifi sound, whether through the power plant or not. I think that’s the only conclusion I can come to. The tv sounds harsh as well as the hifi. Not just to me but to my wife as well. On those rare occasions when the tv is not sounding harsh I know the hifi will sound ok too (whether or not it is plugged directly into the wall.)

First off wow. That really stinks. There is another thread on here about a gent with a 230 volt P10 and swears the old firmware is better but not to your degree of dissatisfaction . Some more questions. Have you tried just using basic equipment . Removing anything not needed also some in the wall and some in the P5.

I say this as in my office I have quad amped setup. And did not want to put the P10 over the top and wanted to use the 4 circuits I have there to it’s full potentional. As it turns out I can use the one P10 for all the amps

And my Complete front end. I have no analog setup just digital . The second P10 does all else , CPU , tv , sat box and a surround sound unit when used. I use multiwave but I have never given the whole thing a go with different options. I have been active on other forums regarding the P5/10. And I do get feed back that some equipment can potentially put noise back on the line coming from the P10/5 outlets . I have raised these questions here and have rec no response. I emailed Paul directly and was told that the out put imp of a P10/5 is about 1000 times lower than a wall outlet. And a such isolates it far better. As there is no real guide nice in power distribution here. I will PM you a guide to power distribution I have found. It does not include such P10/5 units but is a really good guide and may have some answers in your situation here .



It seems you have DC on your powerline.

You could try to use a DC killer and feed your P5 from there.

When the DC is killed your P5 transformer will most likely be quiet.

The P5 itself will also do the job on the DC, but that is only for the equipment behind the P5 as far as I know.

In the link behind a DC killer for 2000VA enough for the P5



As I am sure your correct. It’s only my P5 that does this . I have two P5,s and 2 P10,s. And only the P5 I hear this . How can I determin if this is true. I have a dvm scope . And portible fluke device.


Hi Al,

With your scope you must look at the line in the mitlle the neutral is not exact in the mittle when you have DC. Zoom in on it, sometimes the offset is very little.

Attached files

Stupid me. Not thinking. DC offset.

Thanks I will look at this at home and at office. Over the weekend.

And I will post back


In some cases where there is a balanced 220V feed, there may be a bit of imbalance between the two hots.