This trimmer or reaper amplifier cuts the signal peaks at a voltage determined by the zener diodes. The gain is given by R1 and R1 and the power supply must be symmetrical from 5 to 15 V.
This two-transistor constant current source is from a 1968 documentation. Modern equivalent...
We found this circuit in an old documentation. The integrated circuits used are specific to...
This circuit was found in a 1964 Electronic Design. The circuit can be implemented with equivalent...