We found this circuit in the December 1968 issue of Radio Electronics magazine. The circuit is used with high-impedance magnetic headphones. The transistors are from that time.
This circuit produces a clef sound when a pulse is applied to its input. The damping effect is...
This circuit can serve as the basis for a simple phone. The LM10 is not common today, but the...
This is a possible circuit for the receiver of the previous circuit. Other circuits can be found...