From fat crunch to ultra high-gain distortion, the ST-2 Power Stack delivers famous BOSS distortion with a stunning amount of power that's akin to coveted tube amps and professional amp stacks. The SOUND knob simultaneously blends gain amount and sound character, so you can quickly dial up anything from vintage crunch and punchy drive to full-assault distortion. To add further detail to your tone, simply tweak the onboard two-band EQ to taste. The ST-2 is one very unique distortion pedal, calling on BOSS' years of amp modeling research to bring you real stack sounds in a compact stompbox.The ST-2 delivers the playing feel and power that are hallmarks of stack amps. It was derived from BOSS's extensive analysis of the sound and characteristics of a vast number of guitar amps. This distortion effect delivers authentic tone and expression that responds naturally to picking nuances and volume changes on your guitar. But emulation is only the beginning, as the ST-2 has the ability to go beyond the sound of real amps.The ST-2 lets you enjoy a rich, clean tone when playing soft, and smoothly transition into a fat crunch as you play harder - great for rock ballads or songs that require dramatic tone shifts. Imagine the powerful, driving sound of a stack amplifier. An authentic classic-rock tone is here as well, with crsip overtones. Turn up the SOUND knob for a heavy-metal tone. The ST-2 allows extreme high gain, but offers a powerful low-end and sharp edge at the same time.The SOUND knob is a controller that is uniquely BOSS. Simply set it to the tone type you're looking for. The SOUND knob not only changes gain but sound character as well, from brisk crunch and spectacular drive to earth-shaking ultra high gain.BOSS compact pedals are world-famous for their great sound as well as their road-tough construction, consistency, and reliability. The ST-2 inherits this BOSS-proven design, offering guitarists a solidly constructed pedal that's built to withstand decades of demanding use.BOSS ST-2 Features:Original distortion sound reminiscent of tube-based stack amplifiersProvides a wide range of tones, from vintage crunch to ultra high-gain modern distortionFaithful and accurate response to picking nuances and volume changesSOUND knob controls both gain level and sound characterTwo-band EQ with dedicated BASS and TREBLE knobsRoad-tough BOSS constructionBOSS ST-2 Specifications:Nominal Input Level: -20 dBuInput Impedance: 1 M ohmNominal Output Level: -20 dBuOutput Impedance: 1 k ohmRecommended Load Impedance: 10 k ohm or greaterPower Supply:DC 9 V: Carbon-zinc battery (9 V, 6F22) Alkaline Battery (9 V, 6LR61)AC Adaptor (optional)Current Draw: 36 mA (DC 9 V)* Expected battery life under continuous use:Carbon: 3 hoursAlkaline: 10 hoursThese figures will vary depending on the actual conditions of useAccessories: Owner's manual, Alkaline battery (9 V, 6LR61)Option: AC adaptor (PSA series)Dimensions (WxDxH): 2 7/8" x 5 1/8" x 2 3/8"Weight (incl. battery): 1 lb Boss ST2 Power Stack Overdrive Guitar Pedal.