The Tone City Big Rumble is an Overdrive/Boost effect pedal that combines an overdrive section with a clean booster. Both sections can be used individually or combined. There are two different sound modes: jazz & rock. The overdrive sound can be mixed with the clean signal with the Clean control. The clean boost delivers up to 20 dB gain. The Big Rumble has controls for clean, tone, drive, boost, volume, attack, and a true bypass footswitch for each section.