EL34 Hybrid PP

It's a Dual-Mono push-pull amplifier inexpensive and compact. The first stage features an Hybrid SRPP to permit a direct coupling with the next stage and reducing the complexity of overall phase response. The Output Stage is a Class A1 Ultralinear. The Output Power is 15-16 W (23% efficiency).The criterion network could be inserted between the points a and b or between c and ground, if phase margin measurements are not satisfactory.

H.V. power supply is around a voltage doubler. Voltage at A point is 400Vcc.