Suitable for audio signals in electronic music, this circuit was published in the September 1973 issue of Radio Electronics magazine. The transistors were general-purpose types at the time.
Found in a General Electric documentation from the 1980s, this circuit makes use of a FET...
This circuit is based on an MC1408, an integrated circuit that is not common today. The...
Another way to increase the sensitivity of the circuit with the amplification of the sensor...