Saturday, June 06, 2009

Controlling the Gakken SX-150

Gakken Synth Keyboard Mod

For a while now, I've been trying to figure out how to achieve more control over my Gakken synth without spending a fortune. Sure, I could go the midi controller route, but a c/v to midi kit is $50. I'd read some stuff online about making ribbon controllers so I thought I'd take a shot at it. You know that I'm lazy and don't like carefully executing well planned out projects, so it's no surprise that the end result is less than professional.

What you will need for this project:
a cardboard box or a 3 foot piece of wood
double stick tape
four alligator clip leads
regular point tip test lead
a sharpie
a chromatic guitar tuner
an old data backup tape/pro-grade vhs tape/dat tape

Cut the flaps off the box and fold it down into a strip (or just find a 3 foot piece of cardboard). Run the double stick tape down the middle of the cardboard. Crack open the tape case and pull out about 50% more than the length of the cardboard. Stick the magnetic tape (dull side up) on the length of the sticky tape. Place the clips on each end of the tape (now stuck to the cardboard). Unscrew the two leads from the Gakken's carbon strip [the thing you play it with]. Clip each lead to the respective ends of the cardboard. Using the extra clip leads and test lead, extend the Gakken's stylus so you can reach the cardboard strip. You can now play the gakken by touching the stylus to the strip of mag tape. Look how much more range you have!

Now comes the tedious part. Hook the tuner up to the output on the gakken. Touch the lower left end of the mag strip with the stylus and look at the note it produces. It may be so low that it's silent. Move the stylus to the right until you get a low C. Mark it with a line and the note. Now keep going right and marking every half step. At some point (probably about 3/4 of the way up) the notes will be so high that you probably won't even want to play them. I can't guarantee the scale will be the same for everyone - different brands and grades of tape will have different levels of resistance. I couldn't be more pleased about the outcome of this project. Instead of spending $50.00 - I spend maybe $0.05 - if you include the sharpie I used.

So congrats, your tiny monophonic analog synth is now actually playable. Bueno, no?