"Large-signal analysis of class-A vaccum triode push-pull output stage"

Abstract

A mathematical model of the transfer function of class A push-pull triode vacuum tube amplifiers yields closed-form series expressions for the amplitudes of output spectral components. The results are similar to those of a transistor class A output stage, containing odd-order harmonics and intermodulation components. For small amplitude signals, the degrading components are very small; they monotonically increase with large input tones. The parameters of the model can readily be determined using simple calculations.