Arcam A65 with EMI driving me nuts…


Greetings Forumites, I am looking for ideas how I can defeat right channel EMI in my integrated Arcam A65. It seems to only be in the right channel. The left channel is dead quiet. The EMI does not get louder as I turn up the volume which leads me to believe EMI is coming in after the power stage.

I do not think it is an issue with my speakers as the EMI is present whichever speaker I plug into to the right channel. Also, same problem when I plug in headphones. The right channel has the EMI.

Removing the CD, or other sound sources has no effect. The EMI is still there. It does seem to decrease if I touch the chassis, but not completely. Maybe, there is some grounding problem involved, but the grounding (green wire) and wiring looks tight to me inside the chassis.

I love the amp and don’t want to get rid of it, but this EMI is ruining my sound. I have the service manual and I am handy with a soldering iron. I can easily replace a few caps etc. if need be.

Many thanks.

busk

could be all sorts of things--cable routing, inadequate cable shielding, improperly grounding and ground loops from  antennas or  wall outlets, as well as bad caps or relays. since i understand you still get noise when you remove all the sources and when you swap speakers, it's probably not a cabling issue ( i would try using different cables to eliminate), so before start soldering, i'd try a couple of things:

1. plug the amp into different outlets and see if the noise recurs--you can also try using a ferrite choke or hum eliminator adapter.

2. unplug the amp, let it sit for a couple of days, then try screwing down the transformer really tight (there's a philips screw right in the center)--it could conceivably be some mechanical vibration--be careful.

Something like EMI typically would affect both channels, so it's likely something else is the problem.

I really appreciate these responses. It is strange that the noise is in one channel only. I am clearly pulling in some FM radio broadcast as well as noise. I do have a dehummer plug between the outlet and the unit and a ferrite bead on the power cable to no avail. 

 

best.