We found this circuit in an English publication from the 60's. The transistors are of germanium of the time and the headphones must be high impedance magnetic.
This circuit is from Mullard 1969 documentation. The circuit operates at a relatively high supply...
This circuit was found in the September 1984 issue of Radio Electronics magazine. The circuit has...
This circuit is regulated by zener and provides a voltage of 9 V. The circuit is from a Radio...