Supernait2 and speaker noise

Hi MPW

Have you tried connecting the CD player to another input on the Supernait? 

Hi finkfan

the noise exists even when the CDP is switched off.

it exists when i remove the subwoofer cables connected tot he sub-out as well..

regards

Have you disconnected the CD player completely and removed the interconnect so that nothing is connected? 

i did that just now..

disconnected the CD player RCA cable

switched ON SN2

The MUTE - self diagnostic comes ON - No noise

The MUTE turns OFF - noise starts

Its low at 9 o clock but gets noticeable at 10 o clock and thats where i do my listening..

i like it a little loud

regards

Is it a high pitch whistle or a hiss? 

My SN1 used to hiss when not muted. It wasn’t very loud though 

Hi

Any suggestions or ideas welcome 

Thanks

I had a similar problem with a recent and new SN2 which had a high pitched hum across all inputs (not to be confused with the usual Naim hiss from the speakers, which is very low and normal). The hum wasn't really audible when music was playing with my current phono stage (Rega MC) but audible between tracks when using e.g. a Linn Uphorik phono stage (which is much quieter and probably where I'm headed) when volume around 9-10 (and clearly audible on all "empty" inputs when switching to those). I investigated the issue with my dealer and his demo SN2 also had the same issue with analogue signals (as I recall the problem however did not manifest itself when using Naim streamers). Switching my interconnect from RCA/RCA to RCA/DIN reduced the hum by quite a bit, but it was still there. Might perhaps be a result of the huge transformer being used in the SN2, might be something else. Some will be able to live with it and won't see it as an issue - personally, I didn't want to, as I know Naim kit normally does not do this (my 200/202 in another room is dead quiet) and I did not want to have any nagging doubts as to what might happen when changing other components in my system in the future. Ultimately, I got a very fair deal in returning my SN2 towards a 200DR/202, which I took. Very happy with that (but was also happy with the SN2 apart from the hum issue - it's a great one box amp and I liked that simplicity in my home office).

I think that this type of issue is why I would be reluctant to buy more Naim kit. I accept they are good at what they do, but issues like this that must be known about at the factory would concern me. 

How kit can be sold when it does this is beyond me. All I want is worry free listening and I feel that Naim does not always provide this.

That's just my view, I'm sure many will disagree. I would add though that I am happy with my basic Nait cd and amp.

Mpw. you will get a bit of hiss but it should be at a very low level and not obtrusive (unless you are very sensitive to such things).  That is normal for any Naim amp. It should be constant though and not increase or decrease with increasing or decreasing volume level.  If it does that then that indicates a possible issue somewhere.

Charles44 posted:

I think that this type of issue is why I would be reluctant to buy more Naim kit. I accept they are good at what they do, but issues like this that must be known about at the factory would concern me. 

How kit can be sold when it does this is beyond me. All I want is worry free listening and I feel that Naim does not always provide this.

That's just my view, I'm sure many will disagree. I would add though that I am happy with my basic Nait cd and amp.

I would tend to agree with you - but I've had amplifiers from other manufacturers with similar problems. My SN2 is silent, my CDX2 isn't (except with external PSU, of course) and my Hicap DR is certainly not quiet... but the hum is covered by the music, even at low volumes.

One thing I've noticed, which I don't understand, is that I get a very faint hum through the speakers, even with MUTE on - there's no music, but the hum is still there, even with the volume control at 0. Could it be some sort of signal picked up by the cables, background noise, etc.? Extraterrestrials (who've heard about Naim, of course) trying to get in touch???

SamClaus posted:

One thing I've noticed, which I don't understand, is that I get a very faint hum through the speakers, even with MUTE on - there's no music, but the hum is still there, even with the volume control at 0. Could it be some sort of signal picked up by the cables, background noise, etc.? Extraterrestrials (who've heard about Naim, of course) trying to get in touch???

Could well be something that's being picked up, or, if you have any AV kit attached like a TV or cable receiver it could be from that. There should be no hum through the speakers with everything connected correctly, cables properly dressed etc.. Have a chat with your dealer.  Maybe they can come round sometime and check it out?

Thanks Richard. I will unplug everything and start from scratch. I have a feeling it might be caused by a mains cable which lies too close to one of the speaker cables - although the hum is the same on both sides. It doesn't bother me unduly, but one might as well get it right.

It may be that you don't have a signal ground connected to down to mains earth.  This should be at one point only and is typically provided by the CD player. If your CDP is your only source and it is a one that doesn't earth the signal ground, it can cause problems.

FWIW - I have owned a SN2 since January and use NAC A5 speaker cables and have not experienced any hum in the system.

Hi everyone

many thanks for your responses.

It is one of the reasons the Naim forum is so good  - there are so many contributions and ideas.

It will be my attempt to do this systematically 1 by 1

I feel i owe it to explain and get to the bottom of it

a. Today i removed the sub out cables from the SN2 to the subwoofer and disconnected the subwoofer from the mains.

b. I plan to get a couple of my friends over - trusted ears - and have a music session and i will see their reaction as well

I will run this for some hours and report back

My reporting will be intermittent due to work and family commitments lined up over the next week but report i will..

FWIW - the sound from the SN2 is very nice and i like it lots.

best regards

mpw

MPW, noting where you live, it may possibly be a mains issue.  Friends who have lived there have often reported that the mains was appalling - variable voltage levels, high levels of noise pollution, and regular brown outs and cuts - making running a decent hifi system somewhat challenging...

Hi richard

Mumbai has probably the best power supply situation in India. 

The power outages etc..are long back in the past and in fact i have to scratch my head to think when did we have a power outage last ?

I must admit though , the system sounds much better at night - sonic wise - but the high pitch sound - was observed at night as well.

Some of my friends have taken an exclusive power line for audio itself from their mains ( i have done the same ). 

They run even pricier systems ( 1 room has Euro 100k worth hardware) on the same power supply - on a dedicated line.  There is a dynaudio evidence kept in the sides - waiting for a new master and thats not included in the Euro 100k !

I am suspecting some cable interference - something common to all inputs and that could be the subwoofer cable.

let me run the rig for a few days and report back.

BTW - if you ever come to Mumbai - you are invited to some lovely coffee and music.

best regards

SB posted:

It may be that you don't have a signal ground connected to down to mains earth.  This should be at one point only and is typically provided by the CD player. If your CDP is your only source and it is a one that doesn't earth the signal ground, it can cause problems.

I switched off the source (CDX2) and the faint hum went. When I switch it back on - with or without external power supply - the hum comes back. Are you suggesting that the mains supply is not earthed properly? How can I make sure the signal ground is properly earthed?

Thanks for your reply; and apologies to the OP - I'm aware it's not exactly the same issue and that I may have hijacked his post.

Sam, that's interesting.  Do you have any other sources connected?  

Have you owned the CDX2 from new?  Are you using a Naim DIN interconnect?

No, there are no other sources.

The CDX2 was pre-owned - it's a late 2013 model, and yes, I'm using a Hiline.

It's weird that having the CDX2 connected should actually create the humming noise.  Can you try the standard interconnect in place of the Hi-line?  Just to see whether there's a fault with the i/c?  

Otherwise, I wonder whether the previous owner had the signal earth lifted in the CDX2 by their dealer and never had it returned to normal when it was sold on?

Same result with the standard IC; I will get in touch with the dealer of the previous owner - I know where he bought it from.

I will keep you informed, thanks for your help and suggestions.

Check your mains earth first and the mains leads too, to ensure they are earthing properly and also use an induction pen to ensure all have the correct polarity (easy to get wrong with the Schucko plugs).

Clearly something is amiss.  My SN2 generates just the slightest hiss when no source is playing. Nothing more untoward than that.