Yamaha CA-800 bias and dc adjustments.

1. They say to turn OF the Pre/main coupler. Personally I'd just turn the volume control down...
2. No speaker load.

For Class B:

1. Set voltage between TP 1 and TP2 to - (UH-OH. POSSIBLE MISPRINT ALERT!) Manual says 15 VOLTS, using VR 602.
2. Set DC offset using VR601
3. Set DC between TP 3(+) and TP4(-) to .047 volts using VR 603.

Class A:

1. Set voltage between TP 3(+) and TP4(-) to 0.8 volts using VR604
2. Repeat procedures until each is within limits.

Mark Z.

Thanks for the numbers Mark. That 15 volt measurement is correct. It's even marked 15 volts on the pc board. (-; It just doesn't indicate how to adjust it.

Now that I repaired the popping channel, I noticed a much lower level noise going on in the preamp section. Any chance you have a schematic that can be easily sent electronically?

Thanks for your reply.