This is a nice kit for anyone starting out making, it simply screws together (no soldering needed). The SX-150 is played with a stylus with a continuous contact strip, there are no individual contacts tuned to notes, unlike the Stylophone. This makes it hard to play notes, but is good for sliding pitch effects. However, because it has a small but fully analog synthesis circuit, it can still make usable sounds. Make have published a hack to allow it to be controlled by MIDI which should make it usable for playing notes and sequencing.
The instructions for the SX-150 describe the principles behind the analog synthesis circuits so it’s potentially a good starting point for creating analog synth circuits or maybe even hacking the SX-150 itself. One hack could be to add more synthesis controls such as LFO depth and resonance level, amongst others.
|SX-150 PCB front, the controls and synth circuit capacitors are mounted here.|
|SX-150 PCB back, most of the synth circuit components are surface mounted here.|
The kit comes with a chronicle of synthesis which includes a section on hacking projects. I guess it would help if you can read Japanese… although a few ideas can be got just from the images.
|Gakken Synthesizer Chronicle|