Found in an 1868 Mullard documentation this circuit has a dynamic range of 10 Hz to 25,000 Hz. Modern equivalent transistors can be used.
We found this version of the automotive tachometer in a 1980s publication. Variations from other...
This circuit can be used as a low Power audio booster for experimental projects such as radios,...
June 2017 - These new AVX capacitors are suitable for filter applications, considerably reducing...