This was a bit of long shot but I did some digging though our Archive and I was able to find something.
Here’s what I found, apologies for the poor quality:
I’ll attempt to translate as best I can…
V1 + 38 VDC
V1 - 38 VDC
V2 + 30 VDC
V2 - 30 VDC
Both Channel: 0
Bias Adjust -
Meter in series with V2- at REC 1 on MMA scale. Both pots turned toward center of board all the way. Nominal idle current should be 19-20 MMA adjust right channel pot to REC (I’m not sure on this bit) 45 MMA
After this it’s illegible to me. It seems like it’s something about the left channel though I can’t make out any of the details…
These notes are attached to a schematic. If helpful, I can email you the whole schematic - just send me an email at firstname.lastname@example.org letting me know you want it and I’ll send it right over.
Hopefully this helps some! Maybe others have details that can help out as well.