Instead, we note that the slope of the Q1 load line for class-A push-pull service is 25 Ω, as predicted by the circuit model seen in Figure 2. This principle was brought to bear in a Class-A linear ...

[Bruce] has designed a push-pull tube amp that has enough gain to connect to a portable audio player. The design is closely related to his OddWatt offering from a few years ago. The new amp has ...