surfur

Responses from surfur

Audio Research D70 mark1 + schematic
P.S. I realize the post regulated bias spec of -30.5 is low, spec being -37, but it's the instability that really hurts.Thanks again 
Audio Research D70 mark1 + schematic
Well, This is a pretty old thread now, but maybe I'll get lucky.I have a D-70 I'm troubleshooting for a drop in the bias after about 4-5 min of warm up.I've have it current limited on a variac and was initially elated when I was able to bring the ...