The voltage between the two driver bases won't change much when you replace R42.
But the current through the drivers will
Understood.
Look upon C12 (and all the bias the parts attached to it) as an elevator.
It can rise up and down, almost to the 60th floor and 60 floors down.
But the height of the elevator always stays the same.
OK, But what voltage should I see across C12? How do i know when I have it set right?
A fusable resistor is just a normal resistor that burns up in a controlled way when something is wrong.
Up to you to use fusables or not.
Understood. Just wanted to know if fusible was important here or just a cost saver.
R9 should be 1k. I assume you measured that disconnected, not in circuit.
A wrong value here could upset the balance of the amp.
I measured it just in circuit for an initial reading. going to pull it and test it right tomorrow.
Somewhere I think I was advised the voltages at the bases of the transistors listed in the drawing needed to be exact and so shouldn't the R29,30, and 34 voltages drops etc. Is that right? They are all high.
Thank You