The way I said that wasn't clear. It is on the far side of pin 6. I have noticed in the circuit of the caps and resistors, on the negative sides you can preamp tap at about 6 points, each having a different volume and hiss level. This is the best or clearest. it has QTY 4 -12AX7A and Qty 2-12AT7 but they give no reference to what it drives. An amp guy here thinks its the tube, it didn't work as the combo W/ tubes in, this time either.
Tube1 2 3 4 Tube1 2 3 4 5 6
6l6 6l6 6l6 6l6 12AT7 12AX7 12AX7 12AT7 12AX7 12AX7 looking at amp from the back