Additional components need to be installed for a Fixed Bias Amp to control the bias
voltage. Follow the steps on this page to mount the parts for a FIXED BIAS AMP. You
will be installing a trim pot, a dual ganged pot (in place of the single pot on the Cathode
Bias version), 2- 100k ½ watt resistors and an additional zener diode and mosfet.
Step 6) Mount 2 more 100k resistors in locations R3 and R5
Step 7) Install the 12v Zener (ZD2) at the ZD2 location on the board making sure you
have the band on the diode orientated like the image on the board.
Step 8) Install the 1m trim pot on to the board.