Hum from nSub and hiss from nVi

Posted by: GreenAlex on 09 May 2016

Hello everyone,

I am facing to problems on two different systems on three different spurs^^

OK, I have a nVi in my bedroom and love it. But it being in the bedroom and it being absolutely silent at night, I can very clearly hear a high pitched sound from the speakers when the nVi is turned on. It's not present in standby, but audible when turned on. Even when the digital source (optical) is turned off. I removed all the connections except power and speakers but it is still there. Does anybody have any idea what I could try or do?

The second issue is in my living room system. I have a Naim nSub hooked up to my AV2 (DVD5/AV2/NAP200/NAPv175) and I get an audible hum when the nSub is turned on. A low pitched, constant hum. It sounds like an earthing problem but I am unable to fix it. I tried a different mains outlet (Naim system is on its own spur) but that did not help. I also tried setting to "external earth" and then touched the test-wire to the earth of a different wall socket and also tried touching the case of the AV2. Neither did anything. Does anybody have any ideas? Is there a way to get rid of this hum I have overlooked?

many thanks

Alex

Posted on: 09 May 2016 by james n

Alex - the nSub hum. Is this from the speaker driver itself or mechanical hum from the transformer. Does it go away with the signal connections removed or the sub muted (if from the speaker driver rather than any mechanical hum from the transformer). 

With regards to the n-Vi. Is this coming from the speakers ?. Reason i ask is that my n-Vi used to produce a very high pitched noise from the unit itself just on the edge of audibility which i presume was related to the SMPS - used to come and go but most noticeable when powered up from standby for the 1st hour or so. 

Posted on: 10 May 2016 by GreenAlex

Hi James,

I need to check on the subwoofer tonight whether or not it is audible when the sub is on mute. I think it is....

The noise of the nVi comes from the speakers, not the device itself. As soon as the nSats are hooked up to the nVi (regardless of whether or not there are any inputs connected) I can hear the high pitched noise. I was surprised because I would not have thought that digital amps would make a noise when "inactive". The noise disappears as soon as I press the power button. So I am guessing that whatever is turned off first on power-down is the culprit.

Posted on: 10 May 2016 by james n

Hi Alex - are you saying the noise is there when the n-Vi is on standby (ie rear power switch on, clock showing) and then goes when you press the power button (and the device starts up) and then comes back when you power down ?

James

Posted on: 11 May 2016 by GreenAlex

no no, quite the opposite^^

The noise is only there when the device is turned on. It disappears in standby.

But it is there even when nothing bit power and speakers are connected to it. So it is not caused by a source.

Posted on: 27 May 2016 by Adam Zielinski

Greenalex - not sure if the hum issue is fixed.

What you describe with regards to your sub sounds like a geound loop problem. An isolating transformer (cost around 15) should fix the problem. It is placed in line with your signal cable.

Adam