Jim Yanik wrote:

Ok, I have the schematic for a SG505 in front of me, which ought to be
similar to your FG501 supply,


SG505 PS is not going to be close to the FG501's PS circuitry.

Really? It is drawn just as the OP describes. The only
real difference from his description is they use a 1458 in
the SG505, and a 741 in the FG501.

-Chuck Harris