Function Testing ACC 260 Amp Head after Reparing Preamp Power Amp Board from Shorted Transistor TO3
Acoustic Control Corp ACC 260 261 (The Doors Amp). Power amp board was cooked on the output emitter resistors. Replaced a few dozen resistors and power rail electrolytic capacitors.
Mod 100uf microfarad capacitor
Rubycon, 10uf and 1uf, 2,2 capacitors.
Output transistors, MJ15003 (matched gains cold, using Atlas tester, as best a possible.)
Set tremolo bias, and crossover distortion. Idle current stays around .268 ampere. Transistors stay warm to the touch after several hours of playing music at half preamp volume.
Acoustic Control Corp Forum for more info and schematics.