Keeley 30Ms Double Tracker Delay With ReverbKeeley 30ms Automatic Double Tracker. This 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 Says Chief Engineer Robert Keeley, Since the early days of automatic double tracking, pioneered by Ken Townsend and