Mutron pedals (Musitronics) set the standard for synth-style guitar pedals in the 70s when musicians like Jerry Garcia, Stevie Wonder, Frank Zappa and Herbie Hancock attached their sound to these fantastic pedals. Classic Mutron effects like the Mutron III envelope filter, Mutron BiPhase, Phasor I/II, Octave Divider, Volume/Wah can be heard on classic funk, rock and R&B albums from music’s glory days.
Mike Biegel, founder of Mutron (Musitronics), has released his personal collection of Mutron pedals to public viewing. To get an inside look at every original Mutron design, along with some unreleased prototypes, click here. The original design of his most famous pedal, the Mutron III (envelope follower), is carried on today by Electro-Harmonix in the Q-Tron and Q-Tron+ pedals. The current production-model Mutron III is made by Haz, and is not Mike Biegel’s original design. He recommends buying either a vintage Mutron III or a Q-Tron. Coming from the founder, those are strong words.
The Legacy of Vintage Mutron Effects Pedals
Mutron III (Envelope Filter)
This is the famous, patented envelope filter (aka – “auto wah”) effects pedal originally developed in the early 70s. Jerry Garcia is the most famous guitarist to have used this pedal, and it can be heard on songs like “Shakedown Street,” “Dancing in the Streets” and “Fire on the Mountain” by the Grateful Dead. This Mutron pedal hit more of the mainstream when Stevie Wonder used the pedal on tracks like “Boogie on Reggae Woman” and “Superstitious.”
Mutron Octave Divider
The original boutique octave up/octave down pedal, the Mutron Octave Divider gave guitarists an unbelievable synth-like tone that turned heads everywhere during the fusion guitar era of the 70s. Jeff Beck made the Mutron Octave Divider popular with tracks like “Thelonious.” The Octave Divider takes the original guitar signal as the source signal for the octave effect, giving it a very smooth, sub-octave sound. The circuit of the Green Ringer was used to provide the octave up effect.
Known for his raw ,vintage lead rock sounds, Frank Zappa explored new territory with the Mutron Bi-Phase. This is quite possibly the most inaccessible Mutron pedal on the used market, and it goes for a high price. It’s a dual phase-shifter that is capable of being played in series or parallel, and also in mono or stereo modes. The pedal can also be used with a foot controller (C-100), offering musicians the ability to manually control the phaser’s modulation rate or sweep.
Mutron Phasor/Phasor II
The Phasor I was Mutron’s original phaser and is known for it’s use of transconductance amps within the circuit. It is a somewhat sizable, yet simple pedal. The only controls include depth and rate knobs. The Phasor II, however, is an electro-optical phaser pedal that was designed with an identical “photo-mod” circuit that was used in the Mutron Bi-Phase pedal. This pedal offers feedback and depth controls.
Mutron Micro V
The Mutron Micro V is the Mutron III’s kid brother. It comes in a smaller enclosure and generally sells for less than the Mutron III envelope filter. This little funky box was designed with transconductive amplifiers instead of the photomods found in the Mutron III.
A unique design, the Mutron Volume/Wah combined two pedals that typically take up a lot of pedalboard space: a volume pedal and a wah pedal. By combining the simple volume pedal circuit with a wah circuit into a single, rocking pedal design, the Mutron Volume/Wah is an incredibly versatile pedal that oozes tone. It’s hard to find, so if you find one, grab it.
The Mutron Flanger is also a rare pedal that can be difficult to find. If you do see one, buy it. whether as an investment or a musical device. This bucket brigade flanger was built into an expression pedal, and was one of the first of its kind in the vintage years of guitar effects. Mike built a unique noise-reduction system around the core circuit (driven by the SAD1024 chip, common at the time). The pedal offers oscillator control and uses start/stop frequency control instead of shelf frequency control.
Essential Mutron/Musitronics Resources
- Official Website & Offshoot Musitronics Website from Mike Biegel
- The Fake Mutron (from Haz)
- Premier Guitar Interview with Mike Biegel
- Pro Guitar Shop Article on the Mutron III
- Build Your Own Divided Octave
- Mutron III Clones: