Rarely is any topology fully optimized, since few designers consider noise reduction possible without the aid of heavy feedback or without brute force techniques, such as chokes or regulators. So how can we fairly judge a topology unless it is completely and competently designed? Sadly, we can't.
Do not forget that the techniques outlined here can be applied to a wholly solid-state amplifier with a few modifications. So is there anymore to be squeezed from this topic? I am sure that there is, but we will wait to see what the e-mail brings before returning to it.
(I had hope to include an explanation on how to design a 4 watt OTL amplifier in this article, but it will have to wait until next time.)
"Analyses of Drivers for Single-Ended Push-Pull Stage," Hiroshi Amemiya, IRE Transactions-Audio, Sept-Oct 1955