class A to class AB switch

[ingenieus]

Ingenieus,
did you ask D.Self's permission to post that schematic?
He is a Member here.

Oops, good point. Perhaps a mod should remove the image.

In my defense I would like to point out that is a very old version that I uploaded.

The latest version uses different output transistors, for one.

The Signal Transfer Company: Trimodal Power Amplifier

 

[kenpeter]

I have given an extreme low part count solution in shunt regulated JLH thread.
Enriched A (Classic JLH), Linear A, Square Law A, AB, B. Select your poison...

All the same basic JLH amp with one new transistor for quadrature feedback.
Each mode having its own slightly different current sensing network.