This circuit was found in a 90's EDN. The circuit provides two 15 V outputs and one 5 V output from the 12V voltage of a car battery. The components are from that time.
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...