SuperNait 2 buzz — please help

I really don't have a answer for your particular problem, buzzing through the speakers, that doesn't sound like the amp is performing the way it should. Toroidal transformer hum and buzzing that is slightly audible from the unit itself is normal in certain circumstances, but buzzing through the speakers is another matter.

Who did the service on the amp? I would inquire what specifically was done to the amp.

My hum didn't come through the speakers. So I don't know whether DC off-set could be the problem, but I am sure the mains experts will appear soon!

If it is DC off-set causing your grief, try Isol-8 PowerLine Axis. This PDU only addresses the DC problem and doesn't do any "naughty" mains-conditioning.  

Has the socket you're plugging into an adequate earth?

Naim kit needs an earth for safety.

The livingroom of our apartment in France had no earth connection in any of the power sockets. There was one in the kitchen sockets and there was an unconnected earth conductor looped in the back of the livingroom ones so the socket could be replaced with an earthed one before plugging in the Naim kit, which is what was done. I didn't try unearthed so don't know if it would cause a hum through the speakers but I think it could.

I talked to a local Naim ( Uniti ) dealer about the lack of earth, he didn't seem to think it was a problem, which told me all I needed to know about that dealer.

Hi,

  Try plugging your supernait2 into a friends or someone else's power sockets, and see if the buzz remains this will eliminate or confirm your unit is at fault  

Bplay, for basic, immediate solutions I'd try the following:

1) buy a circuit tester (< $10) and assure there are no polarity issues on the circuit you are currently using or on any other outlets in the house,

2) unplug all other power cords from the circuit (not just the socket) you are currently using,

3) try an alternate circuit (on a  different breaker). If you don't want to move your gear use a heavy duty extension cord rated at at least 15 amps, the shortest length possible.

4) call an electrician to spend an hour and see if he/she can locate the source of noise within your home.

You had the SN2 serviced, the Nait 5si also has noise, so to me it's obviously something in your domestic power supply.

I'd get on the phone to your dealer and have the unit checked over.  If it buzzes just as badly at their place then there's a problem with the unit and it needs looking at.

yeti42 posted:

Has the socket you're plugging into an adequate earth?

Naim kit needs an earth for safety.

The livingroom of our apartment in France had no earth connection in any of the power sockets. There was one in the kitchen sockets and there was an unconnected earth conductor looped in the back of the livingroom ones so the socket could be replaced with an earthed one before plugging in the Naim kit, which is what was done. I didn't try unearthed so don't know if it would cause a hum through the speakers but I think it could.

I talked to a local Naim ( Uniti ) dealer about the lack of earth, he didn't seem to think it was a problem, which told me all I needed to know about that dealer.

Hey Yeti, thanks for the reply — it is for sure grounded I have tested for ground and am all good!

joerand posted:

Bplay, for basic, immediate solutions I'd try the following:

1) buy a circuit tester (< $10) and assure there are no polarity issues on the circuit you are currently using or on any other outlets in the house,

2) unplug all other power cords from the circuit (not just the socket) you are currently using,

3) try an alternate circuit (on a  different breaker). If you don't want to move your gear use a heavy duty extension cord rated at at least 15 amps, the shortest length possible.

4) call an electrician to spend an hour and see if he/she can locate the source of noise within your home.

You had the SN2 serviced, the Nait 5si also has noise, so to me it's obviously something in your domestic power supply.

Thanks Joe, great trouble shooting advice — am going to try the extension cord for sure. I am also going to bite the bullet and get an electrician in. Thanks again

Richard Dane posted:

I'd get on the phone to your dealer and have the unit checked over.  If it buzzes just as badly at their place then there's a problem with the unit and it needs looking at.

This was the first thing I did and it was fully checked buy the distributor. Thanks Richard

Buzzing in amp output can be induced from certain electronics, e.g lighting dimmers. The suggestions of trying with everything else in your home turned off, trying on a different electrical circuit, Maybe trying in different physical location in your home, and trying in different premises (dealer or friend) will indeed confirm if it is the amp or something local to you, thus focussing investigation and possible solutions.

In my case it was an interlink being too close by the power supply of my fiber internet connection modem. Routing the interlink differently solved the problem. Never thought that a smps radiate so much crap.

Yes, the power supply is still on the same mains connection - which should be removed but an internet connection is more important given maslovs pyramide than hifi.

Bplay posted:

Richard Dane posted:

I'd get on the phone to your dealer and have the unit checked over.  If it buzzes just as badly at their place then there's a problem with the unit and it needs looking at.

This was the first thing I did and it was fully checked buy the distributor. Thanks Richard

And it was fine at theirs?

yeti42 posted:

Has the socket you're plugging into an adequate earth?

Naim kit needs an earth for safety.

The livingroom of our apartment in France had no earth connection in any of the power sockets. There was one in the kitchen sockets and there was an unconnected earth conductor looped in the back of the livingroom ones so the socket could be replaced with an earthed one before plugging in the Naim kit, which is what was done. I didn't try unearthed so don't know if it would cause a hum through the speakers but I think it could.

I talked to a local Naim ( Uniti ) dealer about the lack of earth, he didn't seem to think it was a problem, which told me all I needed to know about that dealer.

In my listening room there is newer, properly earthed sockets installed, and also some older ones with only 2 pins. I have tried them all just out of curiosity, but not found any significant difference. That could make significant difference in safety though

No one seems to have mentioned signal ground yet. What source is the OP using? Naim does need signal ground to be linked to mains earth at one point. Traditionally in Naim this would  be via the primary source, usually a CDP In my experience lack of a signal ground can cause a buzz. I had it on my SN1. 

I ran a Rega Saturn CD player in my last Naim system without any buzz problems. I think there is a more serious issue based on the OP's description.