This 555-based circuit was found in the August 1976 issue of Radio Electronics magazine. The tone frequencies are provided by the capacitors connected to the 555 IC.
This microphone preamp found in a 1995 documentation offers stable microphone operation. The...
This high input impedance amplifier stage was found in a 1963 documentation. The transistor...
We found this oscillator in an English documentation from 1977. The symmetrical supply, in fact,...