Mad Professor Number 1"1" IS A DISTORTION REVERB PEDAL DESIGNED TO PROVIDE THE SOUGHT AFTER BROWN GUITAR SOUND OF THE LATE 70S EARLY 80S, WHEN PLAYED THROUGH A CLEAN AMPLIFIER. Like that legendary tone, this pedal produces intense drive while retaining high definition. The pedal also includes a built in reverb circuit to add ambience and depth to your sound. "1"'s gain ranges from medium to very heavy distortion. The amount can be easily controlled via the volume control