The Boss SUPER OverDrive SD-1 gives you the warm, smooth distortion of an overdriven tube amp without blurring the nuances of your picking technique. The unique symmetric drive circuit delivers a more rich, authentic-sounding overdrive effect. Here's an overdrive pedal that has Level, Drive, and Tone controls that make it easy to go from mild to hard, or even use the SD-1 as a signal booster.