Circuit's Blog :Return to Blog
160W Class AB Push-Pull Tube Amplifier by 6550, 12AX7 and 12AU7
This one is a superior class AB push-pull configuration tube amplifier project delivering 80 Watt RMS per channel. Four 6550 high power tetrode vacuum tubes in triode mode and class AB2 push-pull parallel connection forms the output. Several local loops with negative feedback is used instead of global feedback.
The output transformer is an ultra wide bandwidth toroidal output transformer.
To maintain precise dc balance in the output circuit, servo is used.
Project also includes MOSFET regulated power supplies using relative voltage reference instead of absolute reference and based on LM317, 555 timer and IRF96 IRF820 MOSFETs.
The amplifier is designed and tested with the Pspice simulator. Two monoblocks are constructed.
The design is based on the high power tetrode vacuum tubes that are 6550, 12AX7 and 12AU7. For the driver tubes 6SN7 general purpose triode is used instead of 12AU7.
Of course the circuit is not for beginners. You need much more time and experience to construct this amplifier.