This circuit is from a Radio Electronics from October 1970. The circuit uses transistors from that era and has a low impedance output. The resistance R1 depends on the impedance of the input signal.
MCP19124/5 Contains Independent Voltage and Current Control Loops Plus a Full Suite of...
This circuit is designed to control static loads fed by direct voltage. The circuit is from...
This circuit is from an American 1964 documentation. Transistors of the time are used, but modern...