"Noise Stoppers"?

M37,

Just wondering why your concern with noise stoppers? Are you experiencing a level of unwanted noise with your SN2? If you are there are likely better points in your system to look at other than capping the unused inputs. I had the SN2 for three years and thought that for an integrated it exhibited an exceptionally low noise floor. During that time I changed power cords, powerstrips and wall sockets and found that these made subtle alterations to the noise floor along with more overt changes to overall SQ. I never tried noise stoppers on inputs, but have to suspect your money could be better spent on more fundamental components in your system.

M37 posted:

...to reduce the amount of RF interference entering the system."

Anyone who has tried RCA or XLR locking caps for unused inputs?
(There seem to be a few different manufacturers who market these caps but I have not found any "DIN locking caps" yet.)

Got me thinking, how much a set of Super Lumina locking caps would be, if Naim were ever to make such an item.

joerand posted:

M37,

Just wondering why your concern with noise stoppers? Are you experiencing a level of unwanted noise with your SN2? If you are there are likely better points in your system to look at other than capping the unused inputs. I had the SN2 for three years and thought that for an integrated it exhibited an exceptionally low noise floor. During that time I changed power cords, powerstrips and wall sockets and found that these made subtle alterations to the noise floor along with more overt changes to overall SQ. I never tried noise stoppers on inputs, but have to suspect your money could be better spent on more fundamental components in your system.

joerand,
Thank you for your advice and yes, I'm experiencing a loud humming transformer and constant hissing noise from the tweeters that smear levels of microdetails. But I guess this is something I have to accept with this amplifier and 91.5 dB speakers.

I had SN2 with 90db speakers, and there was no hum. Someone on WHF forums had this problem with his Nait 5i2, and after some troubleshooting, discovered it was a ground loop issue caused by some other appliance. Try unplugging some other stuff, see if the hum goes away. If that doesn't work, maybe it's something in the vecinity - TV, phono stage etc. But the unplugging thing should work.

"Loud humming transformer" sounds like the hum is coming from the amplifier and not the loudspeakers. If that is the case then it's not a ground loop. But it could certainly be caused by an appliance in the house, for example a washing machine, TV, air conditioning unit etc, so turning everything else off and then turning them on one at a time until you get the hum from the transformer is a good plan.

if the hum is coming from the loudspeakers, especially if it is affected by the volume control setting, then it is probably a ground loop and disconnecting everything from the SN2 and then putting them back one by one may identify the source of the problem. You need to be careful doing this though and I suggest turning the amplifier off when you are disconnecting or reconnecting things.

best

David

I believe your SN2 inputs are switched by relays (operated by the front panel buttons) & they isolate the wire/PCB track section to the input sockets,  if thats the case I'm pretty sure adding these 'noise stoppers'  or 'shorties'  will not do much.     I would follow Davids tips before anything else.  

Thanks everyone. The hum is coming from the amplifier only so I will follow David's advice.
Regarding the circuit hiss, if I put my ear up close to the speaker when playing music I can hear the hiss through the weaker parts of the music.
Is this considered normal?

M37 posted:

Thanks everyone. The hum is coming from the amplifier only so I will follow David's advice.
Regarding the circuit hiss, if I put my ear up close to the speaker when playing music I can hear the hiss through the weaker parts of the music.
Is this considered normal?

I would say yes this is normal if you have sensitive speakers. Can you hear it from your listening position when there is no music playing (but the volume control is on it's normal setting)?

best

David

No, luckily it's only audible close to the speakers.

I tried this with a Nait XS 2 (I made them using metal bodied phono plugs rather than paying exorbitant prices for little metal caps).

It made not a hapeth of a difference.