This circuit was found in a 1999 publication. Its purpose is to flash two LEDs according to the sound of an equipment and to randomly flash three LEDs at a controlled frequency
The circuit shown in the figure is suggested by ON Semiconductor (www.onsemi.com), based on its...
September 2016 - can be found at Mouser Electronics the new amplifiers with digital variable gain...
This simple 1-transistor audio preamplifier appeared in the June 1968 Radio Electronics magazine. The...