Fisher SA-100 Amplifier
The Fisher SA-100 is a fixed bias push pull EL84 amp capable of about 20 watts per channel. This amplifier is unique amongst EL84 amps in that it is fixed bias and also has adjustments for both AC and DC balance. The original power supply was fairly odd, in that it contained many large power resistors which were baking all the circuitry inside the amplifier. I'd guess that the power resistors were dissipating about 25 watts of power at least. I have redesigned the power supply and removed most of these resistors. This board replaces the can capacitors with a circuit board which mounts to the output transformer bolts.