Transformer hum - again

Posted by: TomK on 01 May 2004

I got up this morning to find my 250 humming away like a large bumblebee. It's normally virtually silent. However after playing a few minutes of music it was back to its normal quiet self. Has anybody else experienced this? Any explanations?
Posted on: 01 May 2004 by pip
This is a problem iget from time to time . It appears to be more noticable on hicap ,I suspect mains interference ie friges, washers or even pc .It would be interesting if people on forum with seperate mains spurs experience same problem. pip
Posted on: 01 May 2004 by J.N.
Hi Tom

Unless a relevant electrical appliance was being used in your house at the time; it's more likely that it's distortion on the supply from elsewhere.

My 135's used to do this at the most bizarre times of day - early in the morning or say 1am, when one would expect there not to be too much demand on the supply.

In a nutshell - crap on the mains. Nothing you can do about it. The good news is that it does not seem to affect the sound quality.

I had to wait for the HT supply in my area to be overhauled to get rid of the intermittent transformer buzzing.
Posted on: 01 May 2004 by mathew farley
When i first puchased my 250 it hummed really badly, but on inspection i found the cat had s**t on it!! Eek

Only kidding!

The hum went away after a few days.
I think you will find it's quite normal for Naim kit, unless it gets really bad/loud.
Posted on: 01 May 2004 by TomK
I'm just puzzled that
a. this is the first time it's happened in the year I've had the new 250 and
b. it cleared after playing about 5 minutes of music.
Posted on: 01 May 2004 by plynnplynn
quote:
Originally posted by J.N.:
In a nutshell - crap on the mains. Nothing you can do about it.


Agreed!
I have dedicated consumer unit, 6 dedicated spurs, dedicated earth deep under the garden - and hum from 250, XPS and Supercap.
Terry