MOTM

Since this came up twice recently:

1) Turn BIAS all way CCW

2) Remove knob

3) Turn shaft of pot until audio barely audible. Back it down
ever-so-slightly

4) Re-attach knob. Tighten knob so pointer line is at 0.

Note: this may "skew" the knob CW or CCW (ie all the way CW not to 1.2 tick)

That's OK!

Paul S.