Oldskoolfan
Journeyman
I seem to recall a substitution list for the obsolete transistors on the control board. Anyone got a link?
Change D6 to a Bat 41 diode and it will bring your bias into the correct range with plenty of adjustment
Copy that. Ordered the diodes and some fresh caps today. Been running the amp all day with no pops, clicks, or scratchiness.Watch polarity and only D6
This is the mod to prevent the amp from going into oscillation?You should change C6 to 470uf and put back to back diodes across it 1n4148
The diodes prevent the early board design from going into latch up.This is the mod to prevent the amp from going into oscillation?
I remember reading about this.
Got a pic of how you installed the diodes?You should change C6 to 470uf and put back to back diodes across it 1n4148
Joe, are the diodes installed anode to anode or cathode to cathode across C6?The diodes prevent the early board design from going into latch up.
Back to back in parallel, so anode to cathode on one end, anode to cathode on the other end.Joe, are the diodes installed anode to anode or cathode to cathode across C6?
Yes, bias is good. Both trimmers are at about 60% of travel. Bias is more stable as well. Has about +/- .1 millivolt after stabilizing. ThanksDid you get the bias corrected?