Very rarely did Jimmy ever use pedals. Live he had a wah and a channel switch, (towards the end of the 70's he used a flanger/phaser type pedal or possibly a tape deck or something to that effect for "nobody's fault but mine". In the studio he didn't use pedals much either. On Zep 1 he used a booster pedal and a wah. The key to his tone is his LP, Marshall amps, and his micing techniques.