The SD-9 SONIC DISTORTION is the “black sheep” of the 9-Series, the Maxon SD-9 Sonic Distortion pedal offers the best characteristics of transistor and op-amp circuits in one compact unit. The SD9 has unique Low Boost/Hi Boost Tone control that offers more low-end beef than other effect pedals, while its Distortion and Output controls can provide up to 55 dB of gain boost. At low gain settings the Maxon SD-9 functions perfectly as a full-frequency overdrive pedal. Higher gain settings turn the SD-9 into a hand-held monster; providing gut-wrenching grind and singing sustain that will make a clean amp dirty and a dirty amp downright evil.