When I wanted to try out distortion with my bass, I first tried out my brother's ditortion pedal (he's a guitarist)... a Nobels DT-1...I liked it (though I didn't fool around with the settings or he'd kill me) so I bought a similar pedal -- the Boss DS-1 distortion ... I know it's a guitar effect, but I got it for really cheap and it gives me a good fuzz/overdriven tone (like Jack Bruce--my idol)... I just keep the Tone all the way down or my bass starts to sound like a really bad analog recording ... I imagine this must be similar to the bass overdrive