Keeley 30ms Automatic Double Tracker. The stereo effect pedal offers an array of studio style doubling effects used for creating thicker, fuller sounding instruments. Also included in the effect pedal is a reverb that simulates the famous chamber in Studio Two. The Keeley 30ms is designed to work with guitar, bass, keyboard, even vocals. In Stereo Double Tracker Pro mode the unit drops the reverb channel in favor of complete control over the double tracked voices. Each of the two voices can be tuned up to 30 cents sharp and flat. Those voices are then delayed by up to 30 milliseconds for subtle to very distinctive doubling sounds. The user can program by internal switches the wet output to have either dry and effected sounds, or just the effect, giving them true double tracking in stereo, live.