3d pan white

How to circuit bend a Gakken SX-150 synth


1--LFO-to filter cut-off (lfo frequency modulates the filter)


2--Filter resonance oscillate (when resonance is on filter distorts and produces a pitch frequency -- simply solder two wires either side of the resister labled above and add a switch too turn the short on/off


3-- frequency to voltage output (wire a output jack to the points shown above to have a volatge output that rises with higher pitch great when used with the theremin as input!!


4-- envelope trigger wire a switch between envelope pionts A and B (shown above) so you can manually re-trigger the envelope


5-- Optical Light control (add a norps12 LDR (min resistance 50ohms max 2m) across the same two pionts as the resistive strip (and a switch to turn it off and on) brighter light increases the pitch etc produces a constant tone.

as always check short before soldering Enjoy!


6-- The filter injection point (the point were R30 and R29 meet) can be used to inject an audio signal through the filter BUT i haven't tested this too much as yet it will need some form of biasing I guess using a 1-10k pot wired as a potential divider would do the trick the signal needs to be at least 0db (2.2v Pk-Pk) i.e. line level NOT guitar.

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Taken on March 22, 2009