The Bandmaster came with many different circuits during the blackface and silverface eras. The blackface head had a diode recifier, one normal channel and a vibrato channel with no reverb. The silverface Bandmaster amps got a 5U4GB tube rectifier and the vibrato channel got reverb. Hence, the name “Bandmaster Reverb”. Due to this the silverface Bandmaster Reverb is less powerful, has less attack and breaks up earlier than the blackface Bandmaster.
1963 -1967 blackface Bandmaster circuits AB763
1968 -1975 silverface Bandmaster circuits AA763, AB763, AC568, TFC-5005
1968 -1978 silverface Bandmaster Reverb circuits AA768, AA568, AA1069, or TFL5005
1988 -1980 silverface Bandmaster Reverb Master volum 45w and 70w
Fender Bandmaster Blackface(AB763) Layout:
Fender Bandmaster Blackface(AB763) inside:
Fender Bandmaster Blackface(AB763) Schematics: