This circuit produces a signal that has the waveform of the sound produced by or near the banjo. The circuit is from an 80's American documentation. The signal must come from an ordinary guitar.
The transistors are 2N918, 2N3464 and other RF equivalents of the time for Q1. For Q2, 2N3399, 2N2894...
This circuit, which can be used as a shield, was found in a 90s Electronic Design. The circuit...
This interesting intercom circuit was obtained from an Argentine publication from the 1970s....