Found in an 1989 R-E Experimenters Handbook, this circuit produces several sound effects that can be modified. The signal must be applied to an external amplifier.
This 1995 circuit uses an audio amplifier that is no longer common today. However, other...
We found this circuit in a Japanese documentation from the 1960s. The frequency depends on the...
The output voltage of this circuit is proportional to the square root of the input voltage....