Fender Vibrasonic

These amplifiers shared nearly identical circuits, with two (or four) 5881/6L6GC tubes in fixed-bias Class AB configuration, long-tailed pair phase inverters, and dual "normal" and "vibrato" channels with independent volume and tone controls; the models were differentiated only by cabinet/speaker configurations, transformers, and rectifiers.

Unlike the Concert-Amp however, the Vibrasonic-Amp was the first production Fender amplifier to use a speaker made by the James B. Lansing company.

Only the prototypes of this amp were built with metal control knobs, as pictured in the 1960 Fender Musical Instruments catalog.

The “Custom” Vibrasonic was part of a series of amplifiers designed by Fender Custom Shop engineer Bruce Zinky, and incorporated the circuit of a stock Twin Reverb in the Steel channel and the circuit characteristics of Vibro-King and Tonemaster amplifiers (two other Zinky-designs) in the Guitar channel.

The “Custom” Vibrasonic was equipped with a special design Eminence 15” speaker and had a relatively short manufacturing run, being discontinued by Fender in 1996.

First production from late 1959, model 5G13 with prototype metal knobs and JBL D130 speaker