Using transistors at the time, this circuit was found in a 1970s documentation. Transistors support modern equivalents for 2A currents at least in the case of the output transistors.
The diagram shows a tone control with the LM381 IC. The circuit is from a Radio Electronics from...
Published in Radio Electronics magazine in March 1963, this circuit uses 4 transistors of the...
In the figure we have the suggestion of coupling an audio oscillator to monitor the CW...