Can UQ2 suffer from humming PSU ?

Posted by: Alco on 06 February 2016

Hi guys,

I bought a s/h mint Nait XS about 4 months ago. Sounds great and my plan was to find a s/h ND5xs to go with it, but... just as I experienced with a Nait 5si two times in 2014, it suffers from an annoying transformer hum, every now and then.

I know that it's not a defect of the amp itself. It's mains polution that's to blame!
(I installed the amp at a friends house and it has been deadly quiet for a week!) The humming occurs a few times a day, in time laps of appr. 10 to 30 minutes.  I'm sure many will say that it's normal with Naim gear, but the humming can be heard easily everywhere in my livingroom.

Now, I know that the chance of suffering from this humming issue get's bigger if you have a component with a larg(er) psu inside.  Therefor, I'm considering... to sell (or trade in) my Nait XS (and ditch the plan of finding a s/h ND5xs) and just go simple, by getting me a new UQ2.

I'm missing the little s/h UQ1 I briefly had last year, and I thought due to the smaller internal transformer, it would be very unlikely that a UQ2 will suffer from transformer hum.

Whatta ya guys think ?

kind regards,
Alco

Posted on: 06 February 2016 by Brubacca

one of the common problems for this is DC on the AC line. This happens because we have more and more non linear power supplies in our devices. They create harmonics on the power line. Also harmonics comes in from our neighbors and local municipal facilities and factories. Do you have a large flat panel TV? Or maybe several in your home?

I use a Emotiva CMX-2 to get rid of this DC problem.  If you are in the US it is an easy inexpensive thing to try. 

Posted on: 06 February 2016 by Alco

Hi Brubacca,

Thanks for your reply and suggestion. I'm aware that my humming problem is related to DC. 
I had the chance to try some so-called DC offset killers. They do kill the hum, but also changed the sound.

I don't have a large flat panel tv. Only one, rather small flat panel tv.
Currently I have one upstairs neighbour and one on the side.

Posted on: 06 February 2016 by Brubacca

The biggest cause of harmonics on the line comes from your local water municipality or if you live near heavy industry.. 

 

I am not sure if possibly a isolation transformer at the hifi would help. 

I felt that my Qute 1 did have some transformer hum. (To answer your question). 

Good luck I hope that others have some help to offer 

Posted on: 07 February 2016 by Adam Zielinski

'Undortunately' my UQ2 suffers from some transformer hummmmmm What is most funny is that it hums at different times than my SuperNait2.

Each one is on a dedicated mains spurr as well.

Had to plug it in via an RFI fileter - helps.