This resistive sensor was found in a 1969 US documentation. The circuit uses transistors of the time, but current equivalents can be employed.
This fuzz distortion circuit was found in old RCA documentation. Equivalent transistors may be...
This circuit with transistors of the time was found in the magazine Radio Electroinics of June of...
Several versions of this circuit can be found on this website. This makes use of FETs that can...