The Vibrosonic Reverb was a guitar amplifier made by Fender.
This silverfaced guitar combo was basically a master volume Twin Reverb equipped with a JBL D-130-F 15" speaker.
It was available with 100 watts RMS of power with a 1960s "tailed" Fender logo before its change to a 135 watts RMS combo featuring a "tailless" Fender decal in 1977.
Features included built in vibrato, spring reverb, Line Out jack socket, hum balance and overdrive boost pots (as of 1977).
The vibrato was only accessible through a footswitch and the overdrive boost was made use of via a push pull function on the master volume knob.