Dating silverface amp
View the underside of the chassis (flashlight helps alot)look for the reverb driver trans.
Its in the middle of the 6 preamp tubes with the removable shields. For a black face, this transformer would have been made in 1964 during the 23 week (—423) The trick to this is they don’t renumber the decades.
Perfect for Twin Reverb, Showman and Dual Showman, Quad Reverb, Bassman 100, etc.
Contains four phenolic 8-pin sockets, four "bear trap" retainers, eight mounting screws, four 470 ohm screen grid resistors (Metal-Film Flameproof for safety), and four carbon composition 1500 ohm control grid resistors.
If you have vibrato problems, changing the vibrato 12AX7 oscillator tube should be the first step (2nd preamp tube away from the power tubes).
If that doesn't solve the problem, changing the components contained in this kit should do the trick. Replacement for the ceramic disc vibrato phase shift capacitors in vintage Blackface and Silverface Fender amplifiers from the 60s and 70s. Available in .01u F and .02u F (See Options to select value) Tips: (1) If you would like to slow down the vibrato speed range (popular for jazz players): There are three caps in the vibrato phase shift circuit - two .01s and a .02.
Contains 3 phase shift ceramic disc capacitors and one optoisolator. You can slow the vibrato speed down by replacing the .01s with .02s (so that all three ceramic disc caps are .02). Install a .02 cap from ground to the leg of the optoisolator that connects to the 10 Meg resistor (brown/black/blue).
Fender RCA VIBRATO SHORTING PLUG Did you know that on vintage Fender amps (Blackface, Silverface), the reverb will work without a footswitch plugged in, but the vibrato will not?
This is the input circuit replacement kit for the following one-channel amplifiers: Bronco AB764 (1967-1975), Champ AA764 (1964-1982, both blackface and silverface), Champ 5E1 (1955-1956), Champ 5F1 (1956-1964), Princeton (1963-1979), Princeton Reverb (1964-1981), Vibro Champ AA764 (Blackface 1964-67, Silverface 1968-1982).