I was recently given an old very home made looking power amp from a friend that
passed away. It looks like an 80s or 90s design.
The PC board has Z8 printed on the back, uses a 2N2920 dual NPN diff pair, TO126 drivers
and looks like it was intended to have a pair of the old TO3P outputs - TO246 IIRC.
The board is actually wired up to some big MT200 Sanken outputs.
Anyone know what this was? I'm looking for a schematic.
TIA
passed away. It looks like an 80s or 90s design.
The PC board has Z8 printed on the back, uses a 2N2920 dual NPN diff pair, TO126 drivers
and looks like it was intended to have a pair of the old TO3P outputs - TO246 IIRC.
The board is actually wired up to some big MT200 Sanken outputs.
Anyone know what this was? I'm looking for a schematic.
TIA
Last edited:
Z8 reminded me of Clive Sinclair's stuff...so as a shot in the dark, I present this link:
Doz' Blog: Sinclair Stereo Sixty Amplifier.
Doz' Blog: Sinclair Stereo Sixty Amplifier.
Z8 reminded me of Clive Sinclair's stuff...so as a shot in the dark, I present this link:
Doz' Blog: Sinclair Stereo Sixty Amplifier.
I wondered where all the hits where coming from ...
Will check on an old manual ... if I find it.
The hand applied black crepe tape design plus the dual package differential input transistor makes me think of early 70´s Motorola "Complementary Transistors Power Amplifiers" ; they published a range from 15W to 120W .
Some Manufacturers, notably Marshall, adopted them but on their own design PCBs.
The hand applied black crepe tape design plus the dual package differential input transistor makes me think of early 70´s Motorola "Complementary Transistors Power Amplifiers" ; they published a range from 15W to 120W .
Some Manufacturers, notably Marshall, adopted them but on their own design PCBs.
I told you it´s a version of early 70´s "Motorola High Power Complementary Amplifiers", with protection circuit chopped off and output Zobel and inductor mounted offboard, probably straight on output connectors.
Way back then I read and reread it so much that I must have worn some ink off the pages
Way back then I read and reread it so much that I must have worn some ink off the pages
Attachments
Yes, with some minor modifications (use of zener diodes to stabilize DC in the Motorola) it is very similar to the classic RCA universally adopted by many manufacturers.
Pacson used it here in its maximum power versions.
Fundamental:
Pair with HFE the pair in input Darlington configuration.
Pacson used it here in its maximum power versions.
Fundamental:
Pair with HFE the pair in input Darlington configuration.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
- Home
- Amplifiers
- Solid State
- Old DIY Power Amp Design - What is it?