Hi David - sorry to message you out of the blue but I see in the past (2012?) you had the same problem with your AU999 that I now have. One of the small cylindrical heatsink mounted transistors (bias setting transistor?) has had one leg break, so now I think I need to replace both of them. In your post on the subject, could the following still be considered to be true?:
I changed the BC408 by a BC237B as used on the other channel which adjusts correctly, and the che current is now adjustable. We should consider the BC237B a good sub for the 2SC281.
My thread on the topic is under the "Sansui" board. Would appreciate your reply. I am in New Zealand and it appears that I can source the BC237B relatively easily here. thanks! simon