[Eeyore]

Don Pearce wrote:

Here's the thing. Bipolar Gm is
enormously bigger than mosfet, and you can use that in an output stage.
You do it with local feedback by emitter degeneration - a fraction of an
ohm does it.

Actually NO. A fraction of an ohm isn't enough. You'd have to use about 1 ohm at least
which would be intolerable in practical designs for obvious loss reasons.

There is a cleverer way to do it which blows away all the classic ideas of biasing bipolar
output stages but it's my secret. That basic design was good for 0.008% THD and I wasn't
even trying hard. It borrows on your idea though, just not the same way.

Graham