HI I've bought the mentoned amplifier and I'm very satisfied with sound but there is very annoying sound from the amp - not speakers. It's high frequency hum that changes a bit when I touch the volume knob. If my amp is turned on at hight I can't sleep. I allready changed the unit for another one and this hum presented in this one too and hum is even stronger. I can hear it 3m away. Is that in whole series? I have listened NAD C352 and there is no hum. My brothers NAD T742 is dead quiet. The sailes man tod me that for this price it should be expected to have some abnormalities for the sake of good sound. I couldn't have Gryphon at home if there was hum like on my NAD C320BEE. I also checked out the voltage in the wall and it's everything OK. My NAD C521BEE also emits a soft hum - almost not noticeable and for that's normal - but amplifier drives me crazy. What should I do - sale(a lose some money) the brand new amplifier and buy C352? Have a nice Day
your NAD 320 hums?I had the same problem but i have fixed it.I found that the hum is caused by the motorised volume control.There is about 0.5 volts rezidual current where it should be none - on the power conections of the motor who turns the volume.The simplest solution - sold a 100 - 200 ohm resistor from one of the two power conection of the motor to the ground bar.As simple as that.I did the same.Also the transformer makes some noise but is acceptable.
Very interesting. I certainly wouldn't expect to have to start soldering resistors to a new amp. Apart from the warranty being voided there's also the small matter of it being a major pain in the butt. I'd contact NAD if your retailer won't take the amp back. I've had a few Nad amps and they've never presented any humming problems. It could be that something in your room is causing interference that the NAD just doesn't like but I would have thought it was pretty well grounded and immune to such things. One thing's for sure though, I wouldn't put-up with a loud humming!
Sounds like dirty power to me--a common problem. See if you can find a good line filter (I found one for $20 under the "AR" brand name last week here in the US, so I know they are available). Don't know what you can find in your area, but check around. This is a product group that is growing rapidly.
I don't think that the problem is in electric polution. Why would then the noise change if I touch the volume knob - not turn, just touch. I had a lot of NAD's and there were no problems like that - I think it's the motor that turns the knob(because before motors in my model boat's start to turn produce the same noise). Why is the NAD T742 connected to the same electric dead quiet? Have a nice Day