All these ab763 amps with reverb has the gain stage in the reverb recovery circuit which the non-reverb amps don’t have. Yes of course some have the mid knob and bright switch while others don’t. The main differences between these amps are transformer size, filter caps size and output/speaker impedance.
Fender tweed bandmaster pro#
The silverface Bandmaster Reverb is a typical ab763 amp and shares basic circuit design with the Super Reverb, Deluxe Reverb, Twin Reverb, Vibrolux Reverb, Pro Reverb and Twin Reverb. It reminds us more of a classic 80w Twin Reverb than a Bandmaster Reverb, and it shared its circuit design with the Pro Reverb and Super Reverb at that time.
The 70W model from 1978 with master volume and push/pull boost had a huge power transformer and big filter caps. As usual the later silverface models were modified to become cleaner and more powerful. Due to this the silverface Bandmaster Reverb is less powerful, has less attack and breaks up earlier than the blackface Bandmaster.
The silverface Bandmaster amps got a 5U4GB tube rectifier and the vibrato channel got reverb. The blackface head had a diode recifier, one normal channel and a vibrato channel with no reverb. The Bandmaster came with many different circuits during the blackface and silverface eras.