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Fw: Farfisa S-80 amplifier

Fw: Farfisa S-80 amplifier

2009-05-14 by Kirk Topits

Hi,
I have a Farfisa S-80 amplifier (from B8-80 or Twin-80 guitar/organ amp), circa 1967, with discrete components. I also have the Farfisa blueprint schematic. However, two of the transistors are blown. In the power amp, there are 4 AU103 switching transistors. However, between these and the transformer are 2 unnamed transistors (SFT 0). These are unusual transistors, with three wires, mounted in the air, about 1/2 inch long tubes, with no writing and some trace of red. I am wondering if any other Farfisa amplifier circuits from this era might have a similar design and better description.
Thanks!
Kirk

Re: [vintagesynthrepair] Fw: Farfisa S-80 amplifier

2009-05-14 by Kirk Topits

These appear to be Mistral Low Frequecy Transistors, and Farfisa used them in several amplifier designs. Anyone have info on Mistral Transistors?
Kirk
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Sent: Thursday, May 14, 2009 10:49 AM
Subject: [vintagesynthrepair] Fw: Farfisa S-80 amplifier

Hi,
I have a Farfisa S-80 amplifier (from B8-80 or Twin-80 guitar/organ amp), circa 1967, with discrete components. I also have the Farfisa blueprint schematic. However, two of the transistors are blown. In the power amp, there are 4 AU103 switching transistors. However, between these and the transformer are 2 unnamed transistors (SFT 0). These are unusual transistors, with three wires, mounted in the air, about 1/2 inch long tubes, with no writing and some trace of red. I am wondering if any other Farfisa amplifier circuits from this era might have a similar design and better description.
Thanks!
Kirk

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