Final stage audio amplifier for music reproduction

摘要

The shunt regulated push pull circuit has a divided load and is designed so that no AC current flows in the cathode resistance of the lower pentode. The push-pull output (Ui) is fed to the control grid of the upper pentode (B2) in the following stage. In the so called "White" cathode follower, the non decoupled cathode resistor of the lower pentode (B1) is used as the main component in a correction system for symmetry distortion, caused by transient variations in the dynamic load impedance. Together the two circuits form a complete two stage output amplifier, which has a low output impedance, but does not rely on feedback coupling.