DIY - Change capacitors - Scott A436
Adjusting the BIAS.Setting the quiescent currents (powers of the amplifier circuits). Do not apply signal to the input of the amplifier, volume 0. Output terminals of senior speakers: nothing connected. Use only a multimeter, and know the precautions and safety measures face a unit. The voltages in the device approaching 250 volts!
Left Channel:Adjust the variable resistor (R808) Check the voltage between (A and B), and set to 8 mV quiescent current.
Right Channel:Adjust the variable resistor (R833) Check the voltage between (A and B), and set to 8 mV quiescent current.
Results:A transformed amplifier, much more musical, more detailed. A great device, this Scott amplifier A 436. A vintage amp that I recommend!
Transistor and Diode Cross Reference
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More potentiometers with Loudness plug! Here is a trick to fix it: Resistance of a 1/2 W in series with the potentiometer (100 KB), on each channel, of course, the loudness function will be able to work, but at the expense of travel. A resistance of 100 k, but will increase the work stroke of significantly potentiometer. 50k is a better solution, to adjust to your taste also for more or less serious.