why Polyphonic Distortion?

Polyphonic distortion is most spread reason, because it exists since the 70'es, and the difference is brilliant, there is no intereference between strings.
Distortion created the rock sound. It started as a technical limitation: By playing the guitar amps too loud, they clipped the sound and thus created overtones and undertones that musicians learned to express the spirit of 1968 revolution.
It made the guitar sing and scream like a solo instrument and chord work became harsh and dirty. Since then, the distortion effect is associated with rock music. Since the 70's, 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, for lovely romantic melodies, space loops and a lot more.
But its still not usual to use its not dirty aspect polyphonically!
When distortion is used on one string, its 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 the first PolyDistortion in 1978 with a Avatar pickup and in 1984 the Paradis PolyDistortion became available. 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...