This circuit from a March 1971 Radio Electronics uses a transistor to stabilize the bias current of the output transistors. The circuit is médium power.
This circuit was obtained from an American 80's documentation. The balanced mixer can be shown in...
This circuit was found in a 90s Electronic Engineering. The quadruple operational amplifier can be...
I found this circuit in an English publication from 1989. This configuration can be mounted with...