If you are referring to the D1, there is no DC being
fed to the output of the PCM63, however it is
directly coupled to the Source pin of the Mosfet. The
current through the Mosfet goes to the negative
rail through a resistor.
If the Source voltage is not precisely DC, that is not
an issue, as the output of the PCM63 is a current
source having a high impedance, and it can tolerate
some DC at its output.
No. Disconect PCM 63 the DACs from the mosfets and connect pin 6 to a 100 ohm resistor to ground. It should be at about zero volts. If this so, go back and adjust P4 and P5 to get 0 Volts at source of Q3 and Q6. Also make sure that the supply vlotages to the DACs are at +5V and -5V.
Hmmmmm.......Dirty Harry and NAD 3020. Now I see why you sent me there. And I thought JLH was John Lee Hooker.
Schematic looks a lot like a Williamson. Don't know why those Brits have a thing about feedback applied to emitters. Yeah, yeah, I know, you call it current feedback. I need to dig out my books from bootcamp to clarify this. AD844 is current feedback in my book.