Founded in 1973 by David Oreste DiFrancesco and John Johnson, DOD Electronics was later purchased by Harman, the parent company of DigiTech. DOD effects are popular within the experimental/noise music community, and are prized for their unique sounds. In 2013, the DOD brand was revived with a number of re-releases of classic effects.

The FX30B Gate/Loop is primarily a noise gate designed to silence ambient signal noise. The unit features sensitivity, release and gate controls, and can also be used as an effects loop or A/B switcher.