NAD C355BEE hum or buzz noise

[admin_exported]

Dear All,

Today while I was turning off my NAD C355BEE I noticed a small hum or buzz coming from the standby buttom. Moving closer I realised that it comes from the toroidal transformer, either it is turned on or on standby mode. This is the first time I notice this since I had it (January 2009) and this is noticeable on silence of the night, during day I never heard this before or even at night.

For the guys here who has the NAD C355BEE: Can you please at night with the complete silence going next to the NAD C355BEE and place your hear close right above the toroidal transformer and see if you hear anything? Only with the unit turned off on the back of taking the mains cable it doesn't do any sound at all, but connected either on or on standby it does this kind of hum or buzz, can't exactly say which one it is.

It's only noticeable now at at night, never heard it or realise that there was this sound coming out from the transformer.

Also I disconneted all interconnects and speaker cables and the sound is still there, if you put your hear against the box right on top where the transformer is. You can only realised this very very small sound like that, going further way you have the perception of this hum or buzz sound at only around 15-20 cms, any further that that you hear nothing.

Please can you check this before I deliver the NAD for repairs and tell here somehing? do it with absolute silence.

Thank you - J.Costa

 

[matthewpiano]

This is quite normal and common to many amplifiers. All the CA amps do it and so does the Pioneer A400.

As long as its not being amplified through the speakers (which would indicate some sort of DC leakage), there is absolutely nothing to worry about and it is not a fault.

 

[Anonymous]

Hello,

Today I putted the coffe machine working and it afects this hum noise, once stoped the hum noise gets back to it's normal sound. And this noise is not heard if I get like 10 or 20 cms await from the unit, and i still have almost 2 years ahead of garantee, so mind as well wait the longest possible, right? Anyway I have asked to NAD about this noise, when they'll reply I will post it here

Any of the NAD C355BEE owners have tryied to listed and see if it does this hum noise? and is it loud or very low loise?

 

[Anonymous]

It's like Matt mentioned, just a characteristic of the amp and nothing to worry about.

 

[Anonymous]

Hello,

I contacted NAD about this hum and they answered me as follows:

"Thank you for your recent request via the NAD Electronics web-site.

Please try adding a power surge protector in the chain of power supply for the C355BEE.

If this doesn't fix the fault of humming, I would contact your local NAD dealer for a possible service call.

Best regards.

NAD Electronics
(mg) "

In my opinion their suggestion will not solve this out, but seems that they do recognize that this hum noise could be fixed.

Again I would like to ask to the Owners of the NAD C355BEE to listen and tell here if there is also this huming. Please

Regards

 

[Anonymous]

The NAD C320 (old one hums) the NAD C352 doesn't but I don't know about this one. Is the noise annoying you?

 

[Anonymous]

Hello,

Actually now that I know it's there it bothers me a little, and I'm not sure if the humming was there since I bought it (February 2009) or if appeared after I bought it because I never noticed any humming...

NAD will repair it if I deliver the NAC C355BEE for this, but what if it comes humming like was before or even worst, what if it comes humming more? Also a change of the Toroid will change the sound?

I know that there are guys overhere that has the same amplifier and already participated in other forums I posted here, so I would like to ask to any of them to see in the silence if their C355 hums of do any noise from the toroid, please, and Tell it here.

Greetings

 

[link]

none on mine but its only 2 weeks old.

 

[Anonymous]

Hello,

So your C355 is only 2 weeks old...mine is about 2 months.

At the beggining I didn't noticed anything, but one day at the complete silence by some strange reason I putted my hear against the upper part right above the transformer and I listened to this low kind of humming...because it is not noticeable at a close distance, only if you put your hear against the metal cover right above the toroid, you did that or just tryied to listen at a close distance?

 

[link]

tried what you did and almost burned my ear

still no hum or i did burn my ear and hear nothing.

 

[Anonymous]

Hello,

Thanks for the efford!

At the beggining I never noticed anything, maybe the humming appeared later on...

Anyway NAD told me to use a power surge protector, but that will only protect against surges, not the humming...

I will wait some more time and then contact my local dealer and ask for a repair, if it was normal as many says your C355 would make that noise too and it doesn't, again thanks a lot.

Anyone else who has a NAD C355BEE can make the same as Link did and see if it does that humming sound ?

Greetings,

P.S. - By the way what is your sistem and how does it sounds?

 

[biggus_1961]

Had mine since August 2008 and occaisionally here a low volumne hum through the speakers but tracked it down to the low wattage bulbs in the house, turn off the low wattage bulbs and no more hum, so maybe a mains conditioner is the way to go and not a surge protector..Even cheaper replace the 'green' bulbs with the tried and true old style bulbs, though iguess i'd be sitting in a room with a 40 watt bulb to appear 'green' !

 

[link]

valkilm:
P.S. - By the way what is your sistem and how does it sounds?

i have diamond 9.1 amplified by 355 with beresford 7510. i'm still searching for the right speaker. im wondering if the 355 could give justice to the new dynaudio reviewed here. listens mainly to 80s and current bands, but also into acoustics, house, electro and the likes.

will let you know if humming occurs later on.