Transformer Hum

I have a similar problem with my 135s, also on a separate spur. Two things that I did simultaneously that improved things by subjectively 80 or so percent was servicing them and sitting them on foculpods (sorbethane feet).  A bargain at 20€ for four.

you could also try a test of turning off all other fuses in the house so only the Hifi is powered - is the hum still present, then the mains is noisy to your house- not much you can do. If there is no humming, you can successively switch on each fuse and find out who the culprit is!

Regards

Matt

Yes, switched off everything else. Seems I must have noisy mains???

Oops just read that you tried the other consumer units already...

how old is the 552? Does it need a service? 

I guess the feet are probably not much help either if you already have fraim

It is 8 years old.  Happy to wait another couple of years for the service, as no plans to DR this year...

A heard tell of a story from the early days of Naim. Julian Vereker was apparently quizzed by a customer at a Hi-Fi show about his buzzing NAP 250.

"If it bothers you, put it in a cupboard" was apparently JV's laconic response.

Ah; how times have changed. It was all so delightfully simple back then.

John.

I got horrible hum after I replaced my elderly Quad 77 Intergrated with a NAIT 5i-2 in my UK bedroom system. It was being fed by the same Beresford Caiman DAC that I had used with the Quad with no hum at all. I was tearing my hair out after trying all different cables etc and after querying it on this forum, got all sorts of weird suggestions ranging from putting a 240/240 mains isolation transformer before the NAIT to wrapping it all up in aluminium foil.

I contacted Stan Beresford, the designer of the Caiman DAC. He had the solution. He explained that Naim apparently use a strange dual level ground system. All I had to do was to connect a 2.5mm/sq single cable from the chassis of the DAC to the chassis of the NAIT. Instant 100% cure. I now get no perceptible hum at all. The NAIT's timing is much more accurate than the Quad and it has a wholly coherent sound stage. When listening to mono, as I am at the moment, it comes from plumb in the centre of the two speakers (DALI Royal Menuet Mk.2's). There is no sense of two speakers at all. 

i get hum on and off, sometimes from 555PS and other times from supercapDRs. sometimes all of them! sometimes quite worrying when it gets loud --but it soon goes away and i forget about it.

enjoy

ken

Some days my components hum like mad, other days they don't. I usually turn the music up a little bit and I can't hear the mains hum.
By the way, this is NOT audible through the speakers but the physical mains hum/vibration, which cannot be cured by adding any kind of earth wire.
I believe Naim equipment often hums.
Even after I moved house, it made no difference. I have dedicated mains spurs and there are some days the power supplies simply hum.

True, never a problem when playing music.  But 6 large power supplies can make a bit of a noise if I just want some silence!  

I hoped a separate spur would make a difference, but seems not and we are all in the same situation.  I hear you - just turn the music up!!

Indeed - just play your music louder. 

As to mains hum and transformer hum - there was a thread two weeks ago on that topic. See if you can find it. 

Yes there are two different stories in this thread.  Hum directly from mains transformers in the Naim units is normally an indication of a bad mains supply (I think I read somewhere that it happens especially if you get a DC voltage superimposed on the AC), but it can also be a faulty transformer. If several units hum this way, the mains is the issue and if it were me I would start to think about buying a mains conditioning unit.

Hum from the loudspeakers is almost always an earth loop problem and one of the posts in this thread explains about that.  This can usually be sorted easily and no-one should ever have to put up with hum coming from the loudspeakers.

best

David

Back in the dim distant past when I had a mono set up with a Quad II pre-amp and Mk.1 power amp, the mains transformer, once you took the cover off, had four clamping screws on the iron leaf, waxed paper core. You could tighten or loosen these to minimise transformer hum. 

For me, it is a mains issue. No speaker hum. A little vibration from them all. Maybe the 552 is the loudest. 

I saw FootTappers thread on the large mains transformer. Not sure if this is a universally recommended solution? (Without potential drawbacks)

Hi Gavin

For some reason, I find that the mains transformers are more prone to hum when a service is falling due.

The remedy in this case is self evident.

If all else fails and you find that you have asymmetric mains (sometimes called DC offset), then the thread that I started a year ago may help:
"Suffering from this transformer hum blues?"

Good luck!  It will be interesting to find out how you get on.

Best regards, FT

J.N. posted:

A heard tell of a story from the early days of Naim. Julian Vereker was apparently quizzed by a customer at a Hi-Fi show about his buzzing NAP 250.

"If it bothers you, put it in a cupboard" was apparently JV's laconic response.

Ah; how times have changed. It was all so delightfully simple back then.

John.

 

A reasonably acceptable response in the early cottage industry days in Salt Lane. TBH I'd expect better of Naim in 2016 John, particularly with the mains supply becoming more polluted.

James