Polydactyle Guitar

 Sound examples (mp3):

  Polydactyle Guitar Improvisation 1 (2.6MB)
  Polydactyle Guitar Improvisation 2 (1.1MB)b
    Two pieces from an improvisation with the Polydactyle Guitar. Played through a Kustom 20W guitaramp with a spring reverb. Recorded with a Shure SM58 microphone and using a DBX 266XL compressor as insert in the mixer.
     

 

Polydactyle Guitar

A Kidspirit Electronic Guitar, given both the standard circuitbending set of pitch-and-speed bends, with a potentiometer, body contacts and a LDR (photocell), plus the addition of two independent LFOs that serve multitrigger and modulation duties.

The name Polydactyle, meaning "with many fingers" refers to the LFO-multitrigger function, that works as the players "extra fingers".

Basic functions:

The basic functions of the guitar include four different modes of operation where you can either play single notes, strumming the red bars like the strings of a guitar, with or without rhythm, or you can select an accompagnment pattern that you can play with different cords, or a 'demo' mode where each button plays a guitar-solo-like phrase.

There is a Timbre button that cycles between five different timbres, a volume control slider, two buttons to control the speed of rhythms, arpeggios or phrases, a headphone output and a tiny socket that I think is an input for a microphone.


Circuit bends:

Pitch/speed potentiometer - controls pitch/speed (clock rate of cpu).

Pitch/speed photo cell - varies the pitch/speed by changing the amount of light that reaches the LDR. By shading with a hand or moving the guitar between light or shadow, this is quite a playable and expressive controller. A switch toggles the photo cell on /off.

Body Contacts - Bend pitch/speed upwards by touching the two brass knobs with fingers or palm. Touching the frontmost button alone adds harsh noise when playing through the output.

LFO1 og LFO2 - two independent squarewave modulation-oscillators, each with a rate potentiometer and a LED indicating rate. Modulation sources for multi-triggering (both) and vibrato (LFO2)

Modulation select - a five position switch that routes the trigger signals from the LFOs to the destinations strum (equals rockin one of the red strumming bars) and change timbre (pushing the Timbre button)

pos.1: LFO1 -> strum
pos.2: LFO1 -> change timbre
pos.3: LFO1 -> strum + change timbre
pos 4: LFO1 -> strum, LFO2 -> change timbre
pos.5: no multi-trigger.

Vibrato - modulation of pitch/speed. The modulation source is LFO2. The Vibrato on/off switch toggles the effect on/off and the Vibrato depth potentiometer controls the intensity of the modulation.