Channel Imbalance at low volumes

@willemj it does indeed happen with all sources. The volume does gain VERY quickly, however the amp has a built in “low-level” button which brings the volume down by 4-5dbs so the knob can be turned up more. Would this be done by a built in attenuator? However the imbalance is still present at the same low audible levels. 

I tried lots of deoxit however it didn’t help. I couldn’t really get to the pot though so I was shooting a little blind - is there any source for a schematic or service manual?

In addition, I moved the amp to my kitchen which is a large room (~40’ long) so I’m listening at higher volumes more often and it’s noticeable less often. 😉

This is a classic symptom of a defective volume control. Get the control replaced.

I had the same problem with an NAD receiver, had it in the shop 2 or 3 times, but they never really solved the problem.  In my case, the left channel would be the same volume but only playing the system louder than I typically enjoyed.
Good luck!

Leemaze,
The fact that the volume gain goes up very quickly suggests that input sensitivity is too high, which is something you may want to addres in any case.
I am trying hard to think why the problem persists at the same sound level, but at a different part of mechanical rotation of the volume control when you push the low level button.