DC Hum problem from my P10 in both standby and on

After moving to a new house I’ve built a new room with 3 dedicated powerlines in to the room + a dedicated line for lights. The room has been soundproffed so at 100dB I can only measure 35dB on the floor above, the room is very quiet so if something as humming it’s very distracting and audioble. And my P10 is humming, step in to the room an you hear it with no problem. Just having P10 plugged in with no components in standby or on you really here the hum from the transformer. So every low parts in a pice of music is canceled out from this noise. Please advise if there is a DC removing device or any trick to remove this. Before I’m forced to disconnect it and send it out to pasture (sell it). Would a P5 be a better bet as it has a smaller transformer?

I’ve had electricians, goverment power controller and the power company on sight to check if either could find any faults, ground loops. $2000 later no fault were found be any ! Even bough new fuses for the breakerbox that auto monitoring this 3 lines and detects if a faulty wire or product is hooked up.


No any reply from PS? I am looking and waiting.

Have you been reading Paul’s Posts the last few days? Might help you isolate the problem. If it is a problem with P10 should be covered under warranty.

Sorry, I must have missed this. Sounds like you have DC on your line. New fuses and the things you’ve tried to remedy it won’t be of any help. The good news is whatever’s connected to the P10 won’t have the same DC as the P10 will block any coming out of it. The bad news is the P10 itself will have hum until you can fix the issue. There are several things you can do, the easiest is to call the power company and have them measure it. Usually they will fix it if the DC is high enough, but it really depends on the utility.

You can also add a Humbuster in front of the P20 if you can find one used. I wish we still made it.

Frank Van Alstine seems to be building a DC blocker.


You might contact him to see if you can pick one up. Hate to see you give up your Power Plant.


I live in Norway so we have hydroelectric power (known for creating DC), powercompany has allready been here an from there ±10% spec they wouldn’t do anything. I’ve contacted AVA hifi and ordered last night these


and also from Vibex. Expensive to have DC, I tried everything suggested in your latest email series’s Paul with no luck.

I’ll poste when I receive the diffrent dc killers


The different makers of DC blockers has come back to me with 2-3 weeks lead time + shipping to Norway so for now I’ve decided to retired the P10 as the system is unusable with it’s noisy transformer.


Well now I`ve tried 3 different DC blocker. Vibex Granada, Kemp Elektroniks Power DC-Terminator Plus and AVA Hifi humDinger.

But the power supply in the P10 is still noisy. I even tried serial connecting all 3 of the Vibex, 2 of Kemp and 4 from AVA before the P10 with no luck. So I can rule out DC as the problem. I`ve heard that Parasound delivers a more costly power supply for their amps as a special order to Norway about $100 more cost price for it to the importer that solves the problem for those in my situation. My P10 is on a 240V line.

Please advise Paul


Is there anywhere you may be able to borrow another P10 (dealer, friend etc) just to see if it may be your P10 unit?

Hi Rocky

There is no longer any dealer or importer in Norway expect just one, Audio Media 7 hours away. I`m the only one that of my friends that has PS audio. My 2 P5 are more quiet.

So borrowing is not an option!


I am also living in Norway and have the same hum problems that you describe.

I also use a Vibex DC blocker on the output of the P10. The P10 is powered via the PW PowerBase isolation platform.

My suspicion goes in the direction of TN net (Terra Neutral) vs IT net (Isolated Terra):



It might be that the P10 deals with one of them better than the other. Do you know which type your local power provider uses, pers1?

Hi Frode

I use Outlet -Kemp DC-Terminator- PS Powerbase - P10

My meter says L1,L2 & L3 ( 3 X 230 / 400V) messure 238-240v

To the meter there is 3 black cables marked L1,L2 & L3 and 2 blue.

According to electrition sheet it’s a TN-400.

all my active DSP speakers power supplies har also steadily humming as well.


If you have 230V between neutral and ground and the same between phase and ground you most likely have a TN net.

I believe the resistance beween ground and neutral is caused by the distance to the nearest transformer in your neighbourhood.

I also have TN net.

The default in the US is TN-C-S.

Have you tried to bypass the Powebase isozone filter?

I believe what I am told is that the Powerbase pure ac filter can cope with both voltages, so if you put in 120VAC, 60Hz you get 120VAC, 60Hz out, and the same apply for 230VAC, 50Hz.

Hi Frode

I have 240V with Ground , Nutral and Line.

Between Nutral and Ground I have 0V and Line and Ground 240v

I expected my 8 powerbases to be wired correctly so I have not even consider that. If you are saying that for me and my power TN-400 they do not work as intended? If so they are for sale. Have you done something to get rid of the humming?



8 Powerbases - that was something… :)

I am not saying something is wrong with the PowerBases. I just wondered if you have tried powering the P10 directly from the wall socket.

I sometimes hear mechanical noise from my sub transformer, but this one bypasses the P10.

I have still not been able to figure out if there is a sole source for the hum. My input voltage is pretty stable and below 1% THD.

I think someone herein also mentioned that the Multiwave vs Sine setting on the P10 might influence the end result.

I am not sure if all my devices appreciate a high MW setting.

Yes all have been tried THD in 0.8 out 0.1

P10 transformers that buzzes

Well last effort to try and locate if what makes the P10 humming I went were few have have gone before!!!

  1. I’ tried cutting the power to all my fuses ( always leaving 1 on to power the P10) and on different circuits - still humming

  2. Unplugging everything in the house besides the P10 - still humming

  3. Turning off the main power line to my 4 closes neighbors Houses - so they had no power ( with there ok) - still humming

4 .Turning off the hole parking structure mains nearby ( help of power company ) - still humming

So this weekend I sold the P10.