Guitar Overdrive pedal effect. The No.1 Overdrive is a tube-like amp on your pedalboard. If you crave a powerful, warm distortion with a dynamic, tube-like sound, prepare to meet your ''can't live without'' pedal. No.1 is the original KHDK Overdrive. Powered by our unique proprietary circuit, the No.1 was born from years of passion and sweat, experimenting and tweaking with the tones we heard, loved and set out to perfect. As versatile as it is bold, the No.1 is designed in the spirit of an overdriven tube amp. It features two gain controls which cascade the gain stages for a rich and harmonic overdrive. Gain one controls the first gain stage from a pure clean boost to a naturally compressing overdrive. Gain two shares one knob with the Bass control. It cleverly controls the gain and the low end of the next gain stage, which adds rich harmonics, bottom end and natural tube-like saturation to your tone. It is designed as an active high-pass filter for the second gain stage and will allow you to set the amount of bottom end with precision. Controls: Gain, Volume, Hi/Lo switch, Bass, Treble. The KHDK No.1 Overdrive is powered by a single 9V battery. You can access the battery connection by unscrewing the bottom plate of the pedal enclosure. Alternatively, plug in an external 9V DC (center negative) power supply. True Bypass.