In my retirement I run a little repair shop for vintage hifi. 1980's and older SS and tube equipment of any vintage. I got in a late 60's Altec 711B receiver in for service. The unit is complete, though pretty dirty. Both channels, all inputs, are heavily distorted. Output transistors were mismatched in gain, (there is not bias or offset adjustments) so I found (2N3055 NPN) matched both pair within 1 point. It got the DC offset to within 0.3 mv from 85mv. The B+ rail is way down (B- is 34V, B= is 21V) Nothing is getting hot. I am suspecting a bad filter cap. But I would like to know more about the power supply and output stage before I start swapping out parts.
Jess10 posted a schematic on December 14, 2011, It's pretty rough for my old eyes to focus on. Does anyone have a better copy of this?
Jess10 posted a schematic on December 14, 2011, It's pretty rough for my old eyes to focus on. Does anyone have a better copy of this?