The Mission Engineering Delta III is a distortion pedal from Mission Engineering. It is not a multi-circuit box with separate boost and fuzz sections; it is a single three-transistor analog dirt unit whose gain knob sweeps it from transparent boost through distortion into what Premier Guitar's reviewer described as "ballsy vintage fuzz"1.
What it does
The Delta III covers three gain territories with one circuit. Turn the gain down and it works as a transparent boost; turn it up and it moves through distortion and into vintage-style fuzz. Because the whole range comes from one analog circuit rather than cascaded boost, overdrive and fuzz stages, the transitions between those sounds are continuous rather than switched1.
Premier Guitar reviewed the pedal in September 2026 and found that, with the right power arrangement, it runs extremely quiet at all but the most extreme gain settings1.
"Mission Engineering's Delta III Si isn't a three-in-one box with independent fuzz and overdrive circuits cascading into each other, but a three-transistor analog dirt unit that can go from transparent boost to ballsy vintage fuzz with the twist of the gain knob."
The closely named Delta III Si is the version Premier Guitar reviewed; players comparing the two should note this page's facts come from that review.
Videos
Sweetwater
Premier Guitar
Brett Kingman
Sources (1)
- Delta III Si Tri-Stage Distortion Pedal Review, Premier Guitar, 2015-10-22
