Low distortion operation of some miniature dual triodes

The variation of distortion with available parameters for low level rc-coupled triode stages is investigated and, the possibility of minimizing second harmonic distortion utilizing signal-source impedance and the nonlinear, noninfinite dynamic grid resistance as an amplitude-correcting device, is explored and found to warrant further consideration. Some data on distortion-level reproducibility for randomly-selected tubes is presented and the limitation of local feedback as a distortion reduction scheme is pointed out. Variation of distortion with signal level is discussed and demonstrated.