We found this preamplifier with 70 dB gain for microphones in American documentation from the 90's. Consumption is low and equivalent transistors can be used.
This stereo preamp uses only two germanium transistors. The circuit was found in old documentation using...
This simple configuration can be found in other articles on this site. The phone used must be high...
This integrated consists of a mono amplifier for battery powered recorders and radios. The load...