Sony TA-E86B Fault

Yes. What brand/type did you install? Technical forum you know.
I put a TKD 2cp2911 in there mounted on its side as they have solder tags, required a couple of chassis alterations a 1.5 mm larger hole and a metal stand cut off from the metal bar running horizontal in the middle of the amp.

At the output of the volume pot there's ~ 5mv channel difference, equating to the ~50mv difference at the output.

If I wanted to test this into a dummy load, what value of resistor would be recommended?