I'm repairing an old amplifier Sansui A-40 which I got from a friend. Here's a portion of the original schematic:
What does the red marked area do, and how does it work? I'm not familiar with that circuit, and I won't dive in for a repair unless I understand the whole circuit.
From what I understand, the left portion of TR06 as an emitter-follower used as an input buffer for the preamp and amp stages. What does the right side of TR06 do?
(In this case the failing in the equipment isn't important, I want to learn the inner workings)
Just in case you need it, the double PNP transistor is a 2SA798. (The full schematic is everywhere on the web, just look for sansui A40 schematic and there you have it.)