Updates: November 2017
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Musico Resynator | Hexsynator

1980s Pitch and Envelope Tracking Synthesizer

With Roland 24-pin Guitar Synthesizer Input

Resynator with Roland 24 -pin vintage guitar input
Don Tavel, Inventor of the Resynator
Don Tavel and Resynator
Click to enlarge

A few years ago I was contacted by Alison Tavel regarding the Resynator, a Pitch and Envelope tracking synthesizer her father Don Tavel had invented in the 1980s.

The Resynator had quite a pedigree from the start, Don Tavel had a Masters degree in Music from the Indiana University Center for Electronic and Computer Music. The difficult engineering design work was done by the legendary Mike Beigel, founder of Musitronics.

The basic Resynator was a monophonic synth with an analog input, similar to the Roland SVP-355. Like the SVP-355, the Resynator had a 1/4" analog input and could be used to both generate its own sounds, and to drive external synths.

However the Resynator also had two built in computers, the Digital Frequency Analyzer (DFA) and the Timbral Image Modulator (TIM). The DFA was used to track pitch, and the TIM was used to generate envelopes for the synth.

The unit was packaged as a floor unit, with a companion foot controller that offered eight foot switches to control various settings in real time. A second version was developed, a rack mount unit.

Where things get really interesting for the vintage Roland guitar synth player, though, is with the Hexsynator, which looks to be a fully polyphonic six-voice extension of the original unit, complete with a cool vintage Roland 24-pin guitar input!

Currently, Alison is working to resurrect the original synth and is looking for funding to cover the costs in developing the Resynator into a commercially available synth, and is working on a documentary film as well.

Check out the screen snaps below from a promotional video Alison put together, plus the text of a review of the original Resynator written by John Amaral.

Resynator - Go Fund Me
Links to more information:

Photos - Resynator and Hexsynator:

Resynator and Hexsynator Resynator and Hexsynator Resynator and Hexsynator
Resynator and Hexsynator Resynator and Hexsynator Resynator and Hexsynator
Resynator and Hexsynator Resynator and Hexsynator Resynator and Hexsynator
Resynator and Hexsynator Resynator and Hexsynator Resynator and Hexsynator
Resynator and Hexsynator Resynator and Hexsynator Resynator and Hexsynator
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Photos - Resynator Video Teaser:

Alison Tavel with Roland G-707 and Resynator Vintage Synthesizer Detail: Resynator Vintage Pitch to Voltage Synthesizer Resynator and Hexsynator 6-Voice Polyphonic Guitar Synthesizer with Roland 24-pin Interface
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Photos - Resynator Advertising:

Resynator Black and White detailed print advertisement Resynator Black and White detailed print advertisement Resynator first version print advertisement
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Product Revew: The Resynator

New: The Resynator

A unique piece of equipment combining a huge array of effects and synthesized sound in one unit that can be controlled in real time by any instrument.
Resynator Synthesizer

By John Amaral
Musician Magazine, October 1980

Resynate your axe! Resynate your guitar! Resynate your sax! Resynate your voice! It you follow the new musical products like I do, you've probably seen the full page ads which have appeared in major publications for well Over a year for a mysterious box called the Resynator. Since it wasn't available in stores, many of us wanted to know where the product was and what it does. Well, the Resynator is available now (factory direct) and is interesting. I'm going to tell you what it does and how to pilot it so that you don't have to go cold into your first solo flight.

The Resynator is a uniquely versatile analog/ digital hybrid synthesizer that can be directly controlled by any signal source such as guitar, microphone, electric keyboard, amplified wind instrument, amplified horn, etc. It tracks the pitch and dynamics of the signal source and produces a wide variety of synthesized sounds via a somewhat unique but straightforward method.

This brainchild Of Don Tavel Of Musico and Mike Beigel Of Beigel Sound Labs represents quite a lot of consideration and research into what synthesis and playing music are all about. To my knowledge, it is the first professional device which combines a pitch follower with a computer and synthesizer. In addition, the design approach to the synthesizer should be meaningful to players who are concerned with performing in real time. In a nutshell, it's somewhere between having presets and having a lot of knobs. After playing with for a little while, I was rewarded with the ability to get a lot of traditional sounds, and some new ones as well, quite easily and efficiently.

Although it doesn't have presets in the traditional sense like a Prophet, most sounds are quickly reproducible, and while it successfully imitates the sound of popular synthesizers like the Minimoog, the Resynator also has some sounds of its own which are produced by the Timbral Image Modulator. It has the unexpected ability to imitate sample and holds, syndrums, gongs, and chimes, as well as standard instruments, like trumpet, tuba, bassoon, clarinet, French horn, and flute. A realistic Chorus effect, which sounds like an ensemble of the above instruments, is easily gotten by a little low frequency oscillator modulation into the Voltage Controlled Oscillator.

The Resynator has some profound implications for the future of electronic music products. It contains two computers. called the Digital Frequency Analyzer (DFA) and Timbral Image Modulator (TIM). The former follows the pitch of the signal source and the latter shapes filter envelopes. The rest of the circuitry is centered around the same modular integrated circuits that the Prophet uses and the types of signal processing techniques that Mike Beigel pioneered at Musitronics. All this says a lot about the care and quality that went into the Resynator's design.

A Player's Machine

To me, however. the most important thing is that control accessibility and the method of synthesis has been rethought with performing musicians in mind. Quite simply. it's a player's machine. You select the overtone you want, then select an appropriate filter envelope. You can do all this very fast with foot switches, your instrument, and the panel controls. Overtone structure, harmonic emphasis or harmonizing interval is selected by playing a note on your instrument and depressing a foot switch, you don't have to stop playing. Also, sustain, filter cutoff frequency and octave up or down are foot switchable. Positive or negative detuning is achieved with a control voltage pedal. This creates complex synced wah. harmonizing, and pitch bending effects.

Actually, the Resynator is a bit more straightforward than many other synthesizers. When you plug in and tune up to the internal reference, you automatically have an in-tune square wave coming from the VCO. The signal from your instrument is processed digitally for pitch information and through analog circuitry for amplitude (envelope) information. The pitch control voltage thus derived is sent to a master VCO. The second oscillator, called FXO (effects oscillator). is quite versatile and somewhat unusual. It can operate as a straight oscillator tuned a fixed interval away from the VCO (harmonizing). It can be phase synced to the VCO for harmonic feedback effects. Finally. it can act as a carrier which is modulated by the VCO. creating overtone structures which can give the most bizarre non-harmonic sounds, the overtone series of regular instruments, or straight ahead synthetic sounds whose overtones have Simply integer relationships When you tune the FXO to a complex interval, you get non-harmonically related overtones. When you tune the interval between the FXO and the VCO to a simple interval, you get harmonically related overtones. Musico calls this process CM (Complex Modulation).

Footswitched Intervals

The most amazing feature at the FXO is the ability to tune its relationship to the VCO by playing a note on your instruments and momentarily depressing a foot switch. An internal computer compares the note you play to A—440 Hz and adjusts the interval between the two oscillators from unison to just about anything you want, You don't have to stop playing to do this. The implications are enormous, The VCO can be pulse width modulated and both oscillators can have their pulse widths set manually. The mix control mixes FXO with VCO resulting in a complex waveform which is sent to be signal processed.

The first signal process is a Voltage Controlled Filter whose control voltage is derived from the Timbral Image Modulator, The TIM is a computer which recreates eight separate control voltage shapes stored in its memory. Any of these eight envelopes can be selected to sweep the filter in interesting ways, some natural, some synthetic. For example. shape with its fast rise and fall is most suitable for percussive sounds like chimes, gongs and synthetic drums. Shape which has a more gradual rise time and a wavering sustain is suitable for horns and woodwinds. Other shapes, notably with its gradual rise and unwavering sustain, are good for creating otherworldly sounds, The speed of the TIM shape and its dynamic range are set with the panel controls Rate and Amount Filter resonance and bass frequency are set with Peak and Cutoff. The onset of the TIM envelope is triggered automatically by each new note attack from your instrument.

Final processing is done as on most synthesizers by a Voltage Controlled Amplifier. This VCA is controlled by a separate envelope generator whose rise time is panel adjustable, but whose decay follows the signal from your instrument unless you override it with the sustain panels switch or sustain foot switch. When the VCA Dynamics switch is on, the loudness of each note is determined by how loud you play. With it off, loudness builds to a fixed value. The overall result is realistic, musical, and feels right when you play. The master mix control adjusts the ratio of unprocessed sound to synthesized sound. It is therefore possible to get three distinct pitches at once: your instrument plus the two Resynator oscillators.


Since it has complete set of control voltage ins and outs, the Resynator can control another synthesizer or be controlled by one. The interfacing possibilities include using it as a pitch to voltage converter for a different synthesizer or TIM controlling phasers, flangers, delays, etc. The back panel has VCO and FXO CV in and out, gate and trigger in and out, and TIM CV out.

Suggestions for improvement: A few subtle changes and additions to the graphics would make understanding come a lot quicker. The Tune knob should be bigger; it's critical and often used. There are a lot of situation where it is necessary to tune away from A=440 Hz and, as with many other synthesizers, the pitch can drift over a few hours playing, so it ought to be easier to recalibrate the primary VCO. Provision could be made for TIM modulating the VCA. Provision could be made for insetting an external signal source into the signal processing chain. The input sensitivity could be increased to accommodate weak signal sources.

The Resynator gets my vote for being the most innovative musical product in a long time. Judging from the low price, they must plan to make a lot of them. I think that players of all instruments (and singers) should give careful attention to its possibilities. The Resynator is available directly from Musico, 1225 N. Meridian St., Indianapolis, IN 46204, at an introductory price of $1980 with a 20-day return policy. What next? Resynate your sex life? Resynate you lifestyle? Resynate your mind? It works.

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Resynator Demo: YouTube (Audio Only)