In this cool video, Antony Smith shows you how simple, yet how awesome it can be, to build your own Bass Fuzz circuit. It has a crispy sound! This video nicely shows the atmosphere of listening, creativity and handiwork that go together when designing your own electronic music instruments. He makes some modifications to the circuit in between playing and you can hear the differences! Also, he plays well:
If you want to make a similar one and mount it into a roadworthy metal package, find parts like Hammond cases on the DIYDSP.com store.
For example, there is a shelf full of the colorful metal Hammond cases, which are sturdy: In fact tour-quality. Stomp switches are on the same shelf.