Mu-Tron Musitronics

Mu-Tron Musitronics
Mu-Tron Musitronics


by Art Thompson
Miller Freeman Books, 1997


The ’70s Just wouldn’t have been the same without Rosemont, New Jersey’s Musitronics Corporation, producer of such innovative and road-worthy Mu-Tron pedals as the Phasor II, Bi-Phase, Octave Divider Micro V envelope-controlled filter; Volume & Wah Pedal, and the Mu-Tron III, one of the most happening envelope-controlled filters ever created. Musitronics also built the U.S. versions of Dan Armstrong’s Orange Squeezer; Red Ranger; Purple Peaker; Yellow Humper; Blue Clipper; and Green Ringer. Musitronics founder Aaron Newman who left his job as chief engineer in Guild’s electronics division to launch Mu-Tron in the summer of 1972 and product designer Mike Beigel provided their accounts of the Mu-Tron years.

Aaron Newman’s Story

While I was at Guild we had a consultant named Mike Beigel. He and his partner lzzy Strauss had a company called Beigel-Strauss Labs, and they had developed a synthesizer that had an unusual controller. Al Dronge, who was Guild’s president at that time, supported its development. Unfortunately, Al was killed in a plane crash, and the guy who replaced him wasn’t interested in electronics. We had an amplifier plant in Elizabeth, New Jersey, and when Guild shut it down, I left the company. Mike Beigel and I discussed what kind of products we could make out of that synth technology. We wanted to make accessories rather than synthesizers. The first thing Mike came up with was the Mu-Tron III, an envelope follower and voltage-controlled filter.

Because of my years with Guild, I knew most of the major music dealers in the Northeast. I went around with a prototype of the Mu-Tron to stores such as Manny’s in New York and Wurlitzer in Boston. The response was very enthusiastic, so we set about looking for some money. A music store owner in Farmington, New Jersey, named Derf Nolde provided a good deal of the start-up capital for the company that we now called Musitronics.

Musitronics began in a converted chicken coop in a very rural part of New Jersey, and remained there the entire time we were in business. Things really took off fast for us. Our first endorser was Larry Coryell, and our first major endorser was Stevie Wonder. We sent him a Mu-Tron III pedal and he fell in love with it. One day Stevie called to tell us he’d recorded a song called “Higher Ground” using a Hohner Clavinet through the Mu-Tron III.

Our next product was the Phasor II and then the Bi-Phase, which was popular with keyboard players. Later we introduced the Octave Divider; which was designed by a friend of Dan Armstrong’s named George Merriman. We also had an extremely good photo-electric volume/wah pedal, but that was near the end of our time and we never made very many.


The beginning of the end for us was around ’77 when we got involved with a thing called the Gizmotron. It was an electromechanical boxing device brought to us by a sales rep who knew someone in the band 10cc. The Gizmotron was invented by band members Lol Creme and Kevin Godley, and they’d used it for the string-sounding parts on their hit “I’m Not in Love.” The only problem was that Lol was the only person who could actually play the thing. We were blown away by the Gizmo’s potential, but in hindsight, we should have realized that it couldn’t work. The Gizmo had some physical limitations that you couldn’t really overcome. For instance, we discovered that if we made them during the winter; they wouldn’t work properly in hot weather. It was the characteristics of the plastics, and none of us were plastics engineers. We were out of our realm.



Musitronics didn’t have enough money to keep going with both the Gizmotron and the Mu-Tron line, so the company directors decided to sell Musitronics. Unfortunately, that’s when we found ARP, a synthesizer company that was in the process of committing suicide with a guitar synth called the Avatar. We sold Musitronics to them in ’78 on a royalty basis, but they folded before we could ever collect a cent. We became Gizmo Incorporated and continued to try to make it go, but then I had a heart attack and that was the end of it.

The Mu-Tron thing was tremendous fun. It was a challenge because we never had enough money. Not that Mu-Tron lost a lot of money, but we just sort of plodded along. We had lots of big-name musicians using our products, but our phaser cost a hell of a lot more to make than the MXR or Electro-Harmonix phasers. We were determined to build the best products that we could. I think if we had been more efficient, we might have lowered our costs enough to survive.

Mike Beigel’s Story

My electronic-music experimentation began in 1967 when I started playing my clarinet into the soundhole of an acoustic-electric 12-string with the volume turned all the way up. At the time I was trying to obtain a simulated drone-string accompaniment to clarinet improvisation. In ’68 I proposed an electronics project titled “Source Dependent Musical Instrument” for one of my courses at MlT and this turned into the thesis for my degrees.

I got an engineering degree and a humanities degree- I was MIT’s first electronic music graduate-and between ’68 and ’69 I built a strange analog device that simulated a drone-string accompaniment to an arbitrary musical sound input. The system diagram was basically a blueprint for every kind of instrument-controlled effect and synthesizer made. Around this time friend of mine named lzzy Strauss and I also developed a real synthesizer that used very different musical controllers. Guild Musical Instruments bought into the project in ’70, and we began making synthesizer prototypes for them.

These synths were different because they had very strange hand controllers. I could play music on them, but they looked and acted like nothing made before or since. They never went into production, however; because Guild’s president died in an airplane crash and the rest of the company wasn’t interested in electronic music.

In ’72 Aaron Newman and I decided to extract some sections from the synthesizer and see if we could make a new product out of it. First we hooked up an opto-electronic-based envelope-controlled filter; tweaked it and turned it into a little product. Digital audio pioneer [and former AES president] Barry Blesser also participated in its design. We first called it the Auto Wah and then marketed it as the Mu-Tron III. Synthesizer inventor Bob Moog’s affidavit helped us get the patent. The Mu-Tron III became quite popular thanks in part to Stevie Wonder; who helped immensely by giving us free publicity and letting us use his name.

Mu-Tron III
Mu-Tron III


In ’73 we prototyped a bucket-brigade flanger; but then immediately shelved it for a phase shifter At the time phase shifters were more popular and a whole lot easier to make. The Mu-Tron Phasor used transconductance op-amps for the variable element at a time when most people were using FETs.

We were aware of most of the effects that were around, but the phase shifter that we were going after was Maestro’s PS- I. MXR also came out with the Phase 90 while we were designing the Phasor, but we gave ours two more stages. Then in ’74 came the Mu-Tron Bi-Phase, which was actually Newmans idea. We made it with photo mods because we wanted a really wide dynamic range. Though the technology was semi-obsolete-even at that time-the photo mod helped give the Phasor its own sound because photo resistors don’t track each other exactly and each has its own particular time constant and subtle form of non-linearity. We even had a special photo mod custom made for us with six photocells in it.

At first the Bi-Phase prototypes sounded too clean, and we didn’t know what to do about it. All the FET-based phasers had a non-linearity to them. In audio terms ours was too good, but in musical terms it wasn’t good enough. I decided to put a feedback control around the phase-shift loop so that instead of distorting the signal it emphasized the peaks where the phase shifter didn’t cancel the signal. This made the sound more interesting without distorting. Our Bi-Phase was the first phaser with a feedback pot, though Electro-Harmonix got a phase shifter to market before us with a feedback switch.


I made sure the Bi-Phase had as many ways of being controlled with oscillators, pedals, or external inputs that I could possibly stick into one box. When we designed the Opti-Pot C-100 control pedal for the Bi-Phase, we wanted to make something that was way high tech compared with everything else. One was the mechanism itself-which was spring loaded and connected with a Delrin hinge-and the other was its opto-electronic linearized control, which basically replaced the pot with a photo-transistor.

After the Bi-Phase we made the Phaser II, which was one-half of a Bi-Phase with only an oscillator sweep control. That was probably our most-popular product. For the Mu-Tron Octave Divider; we joined with Dan Armstrong and George Merriman. We started producing Armstrong’s line of products, and we got Merriman working with us on the Octave Divider. The last products we introduced were the Vol-Wah pedal and the Flanger. The pedal- and LPO-controlled Flanger was quite a piece of work, but that was right before we sold Musitronics to the ARP Instrument Company. We only made about a thousand of them.

The Gizmotron was the great disaster. I had wanted to go into digital audio at the time. I liked the Gizmotron a lot when I first heard it, but it basically ate the company because there wasn’t enough money to do R&D on the Gizmotron and digital audio at the same time. Against my strenuous objections the board of directors decided to sell Musitronics.

In ’80 I introduced the Beigel Sound Lab Envelope Controlled Filter-of which only 50 were produced- and also developed the Resynator Instrument Controlled Synthesizer for a company called Musico. I also designed a mixer for St. Louis Music. From ’79 to ’96 I was heavily involved in the development of RFID products [radio frequency identification, now a global industry with applications in many fields of identification, security and scientific research], which allowed animals to be tagged with a miniature transmitter implanted under their skin. Through my involvement with RFID, I learned about new technologies including ultra-miniaturization, surface-mount design, digital-analog techniques and advanced manufacturing methods.

In ’94 I met former competitor Mike Matthews [president of Sovtek/Electro-Harmonix] at a NAMM show. We talked about effects pedals, and later he asked me if I’d be interested in re-creating the Mu-Tron III for Electro-Harmonix. The new box which is called the Q-Tron, uses the same opto-electronic design of the Mu-Tron III, but I’ve given it some new features and improved its specs. It will be followed by other new types of effect: devices. It’s great to be involved again in the musical products industry after quite an extended “vacation.”

Musitronics Mu-Tron III Patents.