Fender reveb tank dating
The reverb knob on the vibrato channel will have no effect any longer.
This mod is not applicable together with the Pull V1 mod, as you need the normal channel preamp tube.
The Vibrato channel has a duplication of the same controls as the normal channel, plus the addition of reverb, vibrato speed and intensity controls.
We all know that speakers change their tonal character during age. Some amps have long, lush and soft reverb while others are mushy and overwhelming. Some amps are sensitive and difficult to control the reverb on.
One side effect with this mod is a noticable click and a volume difference between tremolo on and off using the new spst pot.
The Normal channel has two inputs, a "bright" switch which compensates for loss of brightness through the volume control when the control is set lower than about "6" on its scalea volume control, treble, middle and bass tone controls.
This mod is relevant only for two-channel amps with normal and vibrato channel.
Plug your guitar into the vibrato channel, then unplug the reverb return cable on the back of the amp the one that comes from the reverb tank output and plug it into the normal channel input.