The Musitronics Corporation of Rosemont, New Jersey, was formed in 1972 in an attempt to salvage an aborted synthesizer project. Founder Mike Beigel had initially been tapped to design a synthesizer for Guild Guitars. After Guild President Alfred Dronge was killed in a plane crash in 1970, the company made the decision to shut down their electronic division to focus strictly on guitars, abruptly pulling the plug on Beigel’s synthesizer. Subsequently, Beigel teamed up with Guild’s former chief engineer, Aaron Newman, to form Musitronics. They decided to extract sections from the synthesizer and see if they could make a new stand-alone audio effect out of it. The result was first called the Auto Wah, and then marketed as the Mu-Tron III. Synthesizer inventor Bob Moog's affidavit helped get the patent. The Mu-Tron III became quite popular thanks in part to Stevie Wonder's use and endorsement of the pedal.
The company offered traditional effects such as simple phase shifters, flangers, and foot-operated wah pedals as well.
Between 1976 and 1981, six pedals were sold under the Dan Armstrong name, even though they were manufactured by Mu-Tron.