Author Topic: alpha112p  (Read 1466 times)

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Offline blastart1

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alpha112p
« on: September 22, 2002, 09:09:00 am »
Is there a schematic anywhere in existance for this amplifier? Does anyone know what the two TO3 power transistors are supposed to be? The PCB looks great but there has been some mods attempted and the transistors have been changed. For one thing they are both PNP which I know is wrong. Thanks

Offline Don T.

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alpha112p
« Reply #1 on: September 22, 2002, 09:44:00 pm »
Hello:
 I think the T03's are supposed to be MJ15022 & MJ15023. We used 3055's and it's counterpart in some of those early amps. The techs used to replace the 3055's with the later MJ#'s. I don't know of an existing schematic, at least I have never found one.
Don T.
Don T.

If it's too loud, you're too old.

Offline blastart1

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alpha112p
« Reply #2 on: September 22, 2002, 10:02:00 pm »
So I guess that Sunn never produced schematics for their SS amps or at least they never allowed any of them out of their sight. That is really a shame. This is a good looking board. It just seems impossible that there would not be a schematic and layout for one of the several models of alpha 112`s that were produced. I will just have to trace it all out and see if any of the mods are a conflict to the normal circut. Thank goodness they are easy to distinguish from the solder resin left behind. They consist of two ceramic caps soldered accross two resistors as bypass caps. And one that seems to be a resistor lifted at one end and a bipolar electrolytic put in line. Thank you for your help.