Really noisy transformer in CDX2

Posted by: Mark J on 22 October 2015

This thing has uber-hum going on. Worst I've ever experienced in anything I've owned - Naim or otherwise.

The mains are cool as I have multiple other sources that behave themselves impeccably.

The local Naim agent suggested get the thing rebuilt with a new transformer but costly. The unit is second hand so not a warranty issue - it's a 2008 build.

Read something somewhere about tightening a bolt on the chassis somewhere to fix. The thing sounds good but the hum is majorly off putting especially for my wife.

Any ideas from the forum?

 

 

Posted on: 22 October 2015 by Richard Dane

Mark, ensuring the retaining bolt on the Tx is correctly torqued may well help.  However, it may just be bad on your particular mains - just because all else is fine doesn't mean anything really.  Plug it in somewhere else in another county and it may well be fine.  What does the previous owner say about it?

Posted on: 23 October 2015 by mikey8157

If you have tried everything else then a mains DC blocker may stop the problem.

Posted on: 23 October 2015 by ianrobertm

Add an XPS - that will fix it...... 

 

AND you get a major upgrade.....

Posted on: 23 October 2015 by Mike-B

I had a CDX2 with a noisy transformer,  but in perstective it was noticable because it was the loudest of the Naim units, meaning all the transformers hum.

I detected a small amount of DC Offset & built a DC filter - that worked beautifully & bought some SQ improvements that I was not expecting,  however it did nothing for the transformer hum !!!  (still have the DC filter BTW)

I tried XPS & YES - per "ianrobertm" - it brings significant SQ improvements to the CDX2 & that alone is well worth the outlay, but be careful the XPS might also bring its own hum, test before you buy.

Posted on: 23 October 2015 by ianrobertm

The XPS can also be a bit picky, with its mains fuses too..... 

Mine is fine - never blown one yet - but YMMV. Many posts about this - some saying theirs will only power up 5 times before its fuse blows....

 

Tx noise/hum is also a much discussed 'issue'. Again, my XPS is fine - as are all my other Naim units with Tx's in - inc my CDX2. I have seen a pile of rejected, noisy Tx's at Salisbury - so it is looked for, during manufacture. 

 

Its is all to do with harmonics on the mains - I have heard all mine 'buzz' madly for several minutes then stop. But it is just a mechanical noise - its not on the outputs. The answer is obvious - turn up the Volume.....

Posted on: 23 October 2015 by catalinmetal

i really hope you're not serious in recommending someone with some issue on his cdp, to get the similar expensive PSU to solve the problem!

Posted on: 23 October 2015 by Mark J

A few weeks back I took the cd player to a friends house on the other side of town. I plugged it in there and his comment was " Jeez, that's noisy"

 

All Naim gear with a Tx buzzes or hums to some degree but this one is particularly noticeable. And it does this 24/7 by the way