This power source was found in a 1968 Electronics World. The transistors are from that time. The current of each output is limited by the transformer.
This circuit is suitable for low impedance m icrophones. Gain is given by the 2M2 resistor. This...
This sensitive circuit was found in old documentation. The SCR can be any of the 106 series and...
This preamp with several inputs using germanium transistors from the time was found in Japanese...