Mu-Tron is a pioneering effects pedal brand founded in 1972 by Mike Beigel and Aaron Newman under the name Musitronics Corporation. Originally based in Rosemont, New Jersey, the company introduced the Mu-Tron III envelope filter — the first stand-alone envelope filter effect ever produced. The pedal shot to prominence after Stevie Wonder used it on the Clavinet riff for "Higher Ground" in 1973, and it went on to become a defining part of the sound of artists including Jerry Garcia, Bootsy Collins, and Frank Zappa. Collins famously stated, "Without that Mu-Tron, there ain't no Bootsy."

Beyond the Mu-Tron III, the original Musitronics lineup included the Bi-Phase dual phaser (used by The Smashing Pumpkins on Siamese Dream), the Phasor, the Octave Divider, the Flanger, and the C-200 Volume-Wah. The company also produced the Dan Armstrong line of plug-in effects, including the Green Ringer and Orange Squeezer. After Musitronics ceased operations in the late 1970s, founder Mike Beigel eventually revived the brand — first under the Mu-FX name, then under the original Mu-Tron banner after reacquiring the trademark.

The revived Musitronics Mu-Tron, now based in Cardiff, California, produces updated versions of the classic designs alongside new creations. The current product line includes the Micro-Tron IV envelope filter, the Bi-Phase II, the Phasor III, the Octavider+, the Boostron II, and the Tremu-Tron optical tremolo, among others. The brand occupies a unique position in effects pedal history, having essentially invented the envelope filter category that countless manufacturers have since built upon.

Mu-Tron has 35 products cataloged on Equipboard, including Phaser Effects Pedals, Filter Effects Pedals, and Harmonizer & Octave Effects Pedals. Their gear is featured by 140 artists, with the strongest followings in Rock, Electronic, and Pop. Notable users include Frank Zappa, Anthony Marinelli, and Bootsy Collins. Most Mu-Tron products sit firmly in the high-end, boutique range.