Ampzilla GAS 500 Repair

The Ampzilla GAS500 (developed by James Bongiorno) is a very interesting device for its time (1980):

• Dual differential input stage
• Tracking/bootstrap supply
• Fully Complementary Push-Pull Output
• High quiescent current (Class-AB near Class-A)
• High power supply capability
• Broadband design
• DC servo control

 

The amplifier was in poor condition. However, I was able to draw out the circuit diagram and thus the repair was possible. I was also able to remove or repair mechanical damage.