This circuit uses old germanium transistors because it was found in an old magazine from 1973. Changes can be made to obtain the same effects with more modern transistors like the BC558. The circuit is interspersed between the guitar and the amplifier input. The potentiometers can be 47k and we have other components whose values can be approximated by those currently standardized. Signal input and output cables must be shielded, and power must be supplied with a 9 V battery or source with excellent filtering.
