gainclone: one channel buzzes

[Jimmy154]

I have a gainclone and one channel buzzes. It's a slight buzz and gets louder the later on in the day it gets. But my speakers are 2 ft away from me so I can hear it and it gets irriating. It has nothing to do with the transformer and rectifier. No matter how I wire the transformer it buzzes on the same channel. And I figure if it was the rectifier it would buzz on both. So where is the problem?

[neutron7]

did you try swapping the inputs to see if the buzz comes from the other channel? iif it changes to the other side then its something to do with the source

its probably a ground loop or other grounding issue.

a picture or diagram of your ground wiring would help people to help you

[Nordic]

Also make sure its not maybe one of the speakers... had that happen before... In the meantime, my money is on a bad solder joint.

[Jimmy154]

The inputs and the speakers are the first things I checked.

I resoldered everything cause I thought it was a bad solder joint too. It did not help Maybe it still could be a bad solder joint

Not sure how to draw a diagram, but I'll try to explain it. My two channels go to a 100 ohm resistor, then to the chassis where they meet up with my earth ground.

[Jimmy154]

It was cause the right side channel signal input goes right by the power wires where the plug is, I think. I rewired it a little and I think it might be a little better now. When the signal input wire is not wired into the channel there is no buzz. You can wire signal wire into right channel and the other end can be run by the power wires and the buzz gets louder or fainter depending on how close it is to the power wires. Inbetween two power wires it is the loudest, like where the switch is. Should of tried it with left channel to confirm, now that I think about it.

Another thing I figured out while doing this is that the volume control or pot (is that what it's called?) I had in there before made it sound worse, I think. I had a pot from an old crappy amp, now I have a pot from an old H/K amp and it is much better.

Also power wire zapped me good haha

[SteveMajerus]

Did you design the boards yourself, or are you using a point-to-point scheme?

In either case, make sure that the non-inverting input (or whereever you reference the amp to ground in your design) has it's own wire to the main signal ground. If there any voltage drops due to power supply filtering caps, etc in the ground path to the non-inverting input, the amplifier will amplify the slight differential input.

I made this mistake on one of my boards and had to cut the ground traces to solder leads on!