Standard SR-157SW

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2SB77 and 2N408 can be used too.

Also AC127 and AC128... those are small...maximum 1 watt of dissipation, for low level audio stages.

Can be used as drivers when powered using 12 Volts... into the output, they can produce 500 miliwatts if attached to heatsinks using thermal compound.

Germanium is very sensitive to heat... gain is low, power dissipation use to be small and thermal drift is enormous...also they use to be noisy.


Carlos
 
hello.
found an old schematic (hifi-nostalgia).............
they are all similar,like today............
greetings..............
 

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I have assembled both during the seventies

Was a brazilian Kit.... the union of Phillips, Ibrape and Miniwatt resulted into a big company that started to sell audio kits.

Ibrape was "Brazilian Industry of components"

And Miniwatt was a division from the Philips factory that made electronic tubes (valves)

and those schematics you show were used...i have assembled both down the seventies... sounded fine for those days standards.

Inspecting the circuit i found some differences...the output used here was matched AD161 and AD162... drivers was AC187 and AC188 and supply was 24 volts DC.

regards,

Carlos
 
Hey, everyone I know this is way old but I was hoping for some help. I recently got one of these and unfortunately it has been modified with silicone transistors and the circuit does seem to have been changed aswell. I would love to get this unit back to stock. Any help would be greatly appreciated.
 
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