[PDF] supro Model (1) - Schematic Heaven. Where All Good Amp TNs schematic re&wn from a version by Schematic Fkavmw Weatherford Amplifiers clús no to any of the information contained this The qnlity of the was poor some values were 1966 SUPRO THUNDERBOLT t to determine. These prts are masked with The Supro S6420 Thunderbolt - Angelfire In 1967 the Thunderbolt name was attached to a model numbered as S6920. The S6920 was very much different from the S6420. The 6920 was in a tall, skinny cabinet with a forward facing turquoise control panel and two knob (Bass, Treble) tone control. Schematics . The tube rectified S6420 schematic. The Solid State rectified S6420 schematic.