Fender Vibrato Pull Switch Kit
This kit is designed for all Fender blackface and silverface amps from 1963 through 1981 with Vibrato, except for the Bronco, Princeton, Princeton Reverb, Showman Amp, or VibroChamp.

Remember that you must have a footswitch connection to the vibrato footswitch RCA jack on the back panel - or at least a shorting plug such as our FSP-100 (included in the kit).    If you are using a footswitch, make sure that the footswitch is working properly.    A bad footswitch, bad footswitch cable, or a dirty connection to the RCA jacks is often the cause of loss of vibrato.   Note:   The Vibro Champ, Princeton and Princeton Reverb amps do not need the footswitch for vibrato operation.    These three models are the exception; all other Fender models from the blackface and silverface era must have a footswitch connection for vibrato to operate.   Also, both the reverb and the vibrato cables must both be connected to the proper jacks on the rear of the amplifier in order for vibrato to function, as the vibrato footswitch receives its ground connection from the reverb connection.
Use all safety precautions in working inside the amplifier chassis.  Tube amplifiers contain high voltage which is stored in the filter capacitors even after the amplifier has been turned off.   Always unplug the amplifier from commercial power, and discharge all filter capacitors before working on the amplifier circuitry.   If you are unsure about this procedure, we strongly recommend that you leave your amplifier in the care of a professional service person.

Unsolder the two wires from the Vibrato Intensity pot (pot closest to the amp's pilot light).   These should be a yellow wire on the outside terminal and a brown wire on the center terminal.   Remove the knob by loosening the set screw, and remove the nut holding the vibrato intensity pot, and remove the pot from the amplifier.

Install the new pull-switch pot, with the lock washer on the inside of the chassis.   Tighten the nut on the front panel.   Install the knob on the pot shaft, and adjust the position of the knob so that the "1" is straight up when the pot is turned all the way down.   Tighten the set screw of the knob.

Solder the yellow wire to the outside terminal of the new pot as shown.    Solder the brown wire (formerly on the center terminal of the old pot) to the open switch terminal on the back of the new pot.

We recommend at least sliding the chassis back into the cabinet before powering up and testing for vibrato operation, to avoid the possibility of electrical shock.

Make sure the FSP-100 plug is inserted in the vibrato foot switch jack on the rear, or your footswitch cable is inserted in the jack.   Pull out the vibrato intensity knob and adjust the intensity.  Push in the knob to eliminate the vibrato effect.
 
 

Copyright ©2025 Studio Sound Electronics - All Rights Reserved
Not responsible for web site errors or omissions