Likewise, the brown/blonde Tremolux, Concert, Vibrasonic, Twin, Pro, Super, Vibrolux, Showman, Dual Showman, and Bandmaster used a sequential numbering independent of model, but as with Fender guitars, these were not used consecutively. The 1956 to 1963 Champ, Harvard, Princeton, Deluxe; the 1956 to 1960 Vibrolux, the 1956 to 1964 Bassman, and all the tube reverb units have their own serialization scheme.
The Champ has a "C" prefix, the Harvard an "H" prefix, the Princeton a "P" prefix, the Vibrolux a "F" prefix, and the Deluxe a "D" prefix.
Our evidence is that we are finding some serial numbers duplicated between models.
For example, serial number A00121 has been found on a Champ dated November 1964 and a Vibrolux Reverb dated February 1965.
Jeff is an amp tech who specializes in Fender amps, i.e.