A Single-Ended Push-Pull Audio Amplifier

An amplifier circuit for push-pull operation of two output tubes that provides a direct output to a grounded load is described. This circuit avoids any necessity for close magnetic coupling between halves of a split primary of an output transformer; it does not use any interstage coupling transformer; and its simplifies the application of feedback from the output stage to preceding single-ended stages. Methods for using this circuit with triode and beam-power output tubes are given, and the ultimate possibility of eliminating the output transformer for driving a loudspeaker is discussed.