Keeley MK3 DRIVER Andy Timmons Full Range Overdrive PedalSet the Drive Switch up for AT Clipping this mode features asymmetrical LED diode clipping and is Andys Super AT Mod sound, offering a bright and more articulate attack. Setting the Drive Switch Down for RK Clipping engages two germanium diodes for a smoother, slightly compressed drive which can sound a bit like a vintage fuzz pedal with a softer, smoother feel. In the AT position, the Tone control features Andys preferred voicing and low end