This old circuit, from the 80's, uses an integrated circuit that is uncommon today. The circuit is intended for loads controlled by triac and the resistors depend on the desired control.
Two operational amplifiers are used in this source obtained in an American documentation...
This class B push-pull amplifier circuit with a few hundred milliwatts of power was found in an...
This circuit is from the Motorola Linear Databook of 1990. The coils must be according to the...