This circuit was found in an American documentation from 1969. Indications of the used transistors are not given, but general-purpose types can be tested.
This small earphone amplifier with germanium transistors was obtained in a Japanese publication from...
This powerful regulator, shown in the figure is for 5V (TTL) is suggested by Motorola and makes use...
We found this circuit in an English publication in 1991. The circuit can be assembled with...