Why Polyphonic (Hexaphonic) Distortion?

Distortion is most spread reason to treat strings separately, because it eliminates the intereference between strings. Polyphonic distortion exists since the 70'es, and the difference is brilliant and a culture shock:

Distortion created the rock sound. It started from a technical limitation: When playing the guitar amps too loud, the clipping of the waves two very distinced effects:

1. Compression: by chopping the peaks, the sound becomes less dynamic and the instruments "sings" more

2. Change of harmonic content: new overtones and undertones which partly are harmonically related and make the sound richer and partly are disharmonic and bring the dirtyness.

Musicians learned to use these sounds to express the spirit of 1968 revolution. The compression made the guitar sing and scream like a solo instrument and the interferences made the chords sound harsh and heavy. Since then, the distortion effect is associated with rock music. The effect is not mainly achieved by overdriving amps any more, but with circuits and software that imitates it. And distortion is used in any kind of music, not only for the desperate scream of the revolution but also for screams of joy in the church, for erotic heat, romantic melodies, space loops and experimental music.

But even 30 years after its availability, its still not common to use the clean compression effect polyphonically!
Standard distortion used with only one string is very flexible and turns the guitar into a singing solo instrument. The clipping causes a compression and turns the naturally quickly fading string into a sustaining note. Plus, there are more overtones, so the sound can be shaped much richer with filters.
But what if you want to play a two or three voice solo with the same sound?
With a mix of strings, distortion does something very different: Its a simple mathematical fact that any changes of a waveform that contains a mix of two frequencies produces the fundamental bass which contains both of those frequencies as harmonics. This effect and the resulting new frequencies are called interference. Interference can be harmonically related, making the sound richer, or unrelated, making it dirty. In musical terms, this means that depending on the intervals you play, a chord sounds fat or disharmonic. Octaves and quint (?) work well, smaller intervals become increasingly disturbing. Every guitar player using distortion knows this well, at least intuitively. Its what limits the harmonies used in standard guitar rock music. And its what makes musicians that use more sophisticated chords not use distortion! Although they may like the sustaining and enriching effect that distortion has on single strings!
A Polyphonic Guitar offers the nice aspect of distortion for all musical styles without any harmonic limitations. It also makes solo work cleaner, because even the most clean guitar players cannot avoid that sometimes the transition between notes create interference.

I built my first PolyDistortion in 1978 with a ARP Avatar pickup and in 1984 the Paradis PolyDistortion became available. Here you find pictures and details about this hardware. It had very little contol options because we wanted it to work in the guitar and any potentiometer would have to be a 6 or 12 fold... but I think it sounded cleaner and richer than the Roland GR100 and the distortions in their guitars. I never tried Keith McMillens ZETA PolyFuzz and do not know any other polyphonic distortion (or hex-fuzz as they called it) available in the 80ies. Newer GR synths did not have distortion built in either.
Listen to a Demo I recorded with the analog PolyDistortion in 1984 and observe the dynamics !

In the 1995, Roland brought the first digital polyphonic distortion with the VG-8 and its followers VG-88, VG-99,,,. The huge amount of parameters became controllable. Even more so within the computer. Thats why we made a VST plugin version of PolyDistortion at Mathons, which lets the musician choose how much he wants the parameters to "follow" (change from string to string) and gives more options to mix strings to achieve aspects of the traditional rock distortion with more harmonic freedom.
Listen to a Demo I recorded with the Mathons Polyphonic VST Plugins in 2005 and observe the pan and pitch options added !
(the little white noise was from that prototype firewire guitar and is long gone... yes, I should do a video, we have new features...)

Keith McMillen's StringPort will hopefully finally open all those possibilities to the world!

To feed such systems, polyphonic guitars were offered by: Rolf Spuler, Godin, Gibson, Parker, Kramer,,,

More polyphonc pickups have become available, too: Roland, Paradis, RMC, Graphtech, L.R.Baggs, Shadow, Ubertar, Copeland, Misterstarshine,,,

Here and here some usefull info about the Roland wiring and break out box

Less flexible, but easier for the musician: Line6 built a polyphonic modeling system into the guitar

this leads back to the main story:
virtually all kinds of effects become more expressive and intuitive when they are applied to each string !!