Dating silverface fender enza sambataro dating
Fender never printed any since there were plenty of leftover AB763 tube charts available and these were used well into 1969.
Although the cosmetics changed, the circuits remained unaltered from the blackface circuits on the earliest silverface amps.
The only thing connected to the bias cap/diode is the tremolo circuit.
The cathodes are tied together and connected to a single 165-ohm resistor and 80 mfd 150V bypass capacitor which are both grounded at the other end.
The main focus of this article will be speakers found in Fender amps, but before we get into that topic let’s go over a few other areas first.
If you see one of these cathode biased amps, please let me know! The wire from the two 220K ohm bias resistors is connected to the brass control panel ground plate.Of course, the most foolproof way is to pull the chassis and look at the layout.In fact, on the 40-watt and 80-watt amps you can simply pull the chassis out about 2 inches and look for the big honking ceramic power resistors that are connected to ground from the cathode (pin 8) of the power tubes.This cathode set up is similar to, but simpler than, the AC568 circuit.Every other part of the circuit (power and preamp) is identical to the blackface AB763 schematic.