Self on Audio, 3rd Edition

Chapter 29Distortion in power amplifiers

Part VIII: class A amplifiers (Electronics World, March 1994)

The class A amplifier described in this chapter has now been in production by The Signal Transfer Company [1] for twenty years without so much as a component value change, which I think indicates it is pretty sound. I have to admit that I was initially nervous about having the voltage reference and quiescent-control subtractor sailing up and down en bloc with the amplifier output, but there was never a hint of a problem. This is a lesson to anyone nervously contemplating a complicated output stage, but one thing you must never omit is practical measurements on a real physical amplifier.

I have never been tempted to upgrade its power capability, ...