The SD9 has become a legend since it came out in 1980. Wide variety of distortions, from punchy overdrive to striking fuzz, with a complete frequency response, minimum tone coloring and a huge 42dB gain. When most overdrive and distortion pedals have circuit that either cut or boost high frequencies, the SD9 uses a circuitry that cuts or boosts low frequencies. Features: Bright distortion with precise picking response over the entire frequency range.Sweet harmonics accentuate high-end tones. Easy-access, no tools battery compartment. AC jack to connect optional AC adaptor for long hours of continuous use. True Bypass Switching lets your instrument's signal pass through a non-electronic bypass linewhen the effect is disengaged, feeding your amp with direct, unaltered signal from your instrument.Low noise mechanical switch is used for effect/normal switching. LED to indicate effect/bypass and battery condition for trouble-free performance. MADE IN JAPAN Specifications: Input Impedance 500k ohms Output Impedance 10k ohms Maximum Gain 42dB (1.5kHz) Equivalent Input Noise -115dB or less (input shorted IHF-A weighted) Control DIST,TONE,LEVEL Switch BYPASS/EFFECT Power Supply 6F22/6LF22 9V battery x 1 or Maxon AC adaptor Power Consumption 6mA/9V,7mA/10V Battery life manganese dry battery more than 76hours 25deg C / 77deg F(Panasonic 6F22NB) Dimensions 74(W)×124(D)×54(H)mm Weight 580g (including battery)