buzzing in right channel [solved]

[martok]

My amplifier, with Speedball installed, has a buzzing sound in the right channel which becomes noticeable when I turn the volume knob to around 70% and gets louder until around 80%. I only noticed this when I installed a pad for the input to get more potentiometer travel. When I removed the input attenuator pad, which I thought was the problem, the buzzing was still present at 70% to 100% volume. I changed both tubes but this did not fix the noise problem.
I also tried replacing the volume pot, with a PEC, but the noise was still there in the same position.

I am open to any suggestions as to what the cause of the buzzing could be. 
       

[Paul Birkeland]

Does this happen when a source is plugged in?

Are you listening at these levels?

[martok]

This occurs whether there is a source connected or not, except when the source is plugged in, the buzzing goes away at about 90%.
I dont listen at these volume levels, and it wasn't a problem for the few months I used the amp. But I attempted to install a TKD pot today and when i tried listening the buzzing was consistent at all levels. I suspect its because of the resistor arrangement inside the tkd that makes the problem more pronounced.

[Paul Birkeland]

Was this buzzing present pre-speedball?

[martok]

It took some time, but I found what was causing the buzzing noise in the right channel. I had previously swapped speedball boards left to right, but this had no effect. Eventually I noticed that the red wire coming from the pot was running right beside the heater wires toward the input tube. I rerouted the red (signal) wire to approach the socket terminal from another direction and this completely fixed the problem.