I removed the incorrect 4.7k ohm resistors R626 & R627 and installed the correct 4.7 ohm resistors. It's working!
Class B Mode bias was set at 50 mV
Class A Mode bias at 850 mV
It sounds amazing, really. I've had a chance to listen to a lot of cool vintage sets and amps but this CA-800 is moving to the top of my favorites list!
Thank you avionic and mbz for weighing in. I really appreciate the effort and the mental nudge.
In case anyone else comes across this thread and is working on the CA-800 amp board, here's a little more detailed image of the components: View media item 15347
It sounds amazing, really. I've had a chance to listen to a lot of cool vintage sets and amps but this CA-800 is moving to the top of my favorites list!
The CA-800 is a good amp, the CA-1000 is better and the CA-1000II is slightly better again. All share the same basic mechanics=PITA to rebuild.
Yamaha took a slightly different tact with the CA-1010 and 2010 (both same/easier rebuild) which are impressive but some people prefer the CA-1000