NAD 3020 Transformer buzz

[Neopsp]

Hi all.

I own 2 Nad 3020's and a while back they both started to make a buzzing sound when i turned them on or turned them off. It appears they stop making the noise (sounds like when electricity sparks) when they get a signal. It only lasts a few seconds but varies. One day i turned the amp on without speakers attached and heard the same noise as is usually played through the speakers! I opened the amp and traced the noise as comming from the transformer. Has anyone had problems with this before? Will I need to replace the transformer? It just seems strange that both my amps are doing this
Thanx all
Neopsp

 

[halojoy]

Hi all.

I own 2 Nad 3020's and a while back they both started to make a buzzing sound when i turned them on or turned them off. It appears they stop making the noise (sounds like when electricity sparks) when they get a signal. It only lasts a few seconds but varies. One day i turned the amp on without speakers attached and heard the same noise as is usually played through the speakers! I opened the amp and traced the noise as comming from the transformer. Has anyone had problems with this before? Will I need to replace the transformer? It just seems strange that both my amps are doing this
Thanx all
Neopsp

it can be the windings in trafo, somewhere a wind can be burnt, and it speaks.
Have you checked out the Big Caps?

 

[trwh]

How loud is this buzz exactly? If it's quite loud, there could be a safety issue - you could take the amp to a service technician. On the other hand, I have seen many pieces of equipment that make quite a lot of mechanical noise as part of their normal operation.

Tim.

 

[Neopsp]

well the buzzing is not too loud but is faintly audible when the speakers are not plugged in. When they are plugged in it is quite loud and very anoying. The volume knob doesn't affect how loud the noise is. I think i will take them in for a service as soon as i get money again. (student ...) I havn't checked out the caps nor have i replaced any components yet coz if i make it stop working now it will have to stay that way for at least a few months. If a wind in the transformer is burned can that be dangerous? The one amp does build a little bit of potential on the chassy. I will be building my t-line's sometime (which has had to wait a year coz of fianances) which will be bi-amped and the last thing i want is for my tweeters to get damaged coz of this noise (and have to wait another year ). Is that a possibility?

 

[pinkmouse]

The other possible reason for buzzing transformers is noise on the mains. Have you intalled a new fridge or aircon/heating sytem recently? These tend to be the worst culprits, followed by lighting dimmer switches and power tools.

 

[jarek]

I own 2 Nad 3020's and a while back they both started to make a buzzing sound when i turned them on or turned them off. It appears they stop making the noise (sounds like when electricity sparks) when they get a signal. It only lasts a few seconds but varies. One day i turned the amp on without speakers attached and heard the same noise as is usually played through the speakers! I opened the amp and traced the noise as comming from the transformer. Has anyone had problems with this before? Will I need to replace the transformer? It just seems strange that both my amps are doing this

Have you connected mains ground to audio ground? If so, try disconnect them..

Regards
Jarek