A friend found a Casio SK-1 for $4 or $5 at a garage sale and asked if I'd be interested in modifying/circuit-bending it .  I thought it would be fun and figured why not?

The power switch was acting strangely and cutting out.  Once the keyboard was opened I saw it uses a brush system to turn the device on.  A little component cleaner and gently bending the brushes helped. then it was on to general cleaning.  Warm soapy water takes care of the plastics and  stiff bristled brushes take care of the dusty circuit board. 

I always find that it's easier to remember where buttons and switches go when you take pictures of the front and insides.  :)

Then I removed the speaker and installed the RCA patch bay.  I normally don't want to remove functionality from something I modify but this made it much easier to keep everything in a nice tight package.  I didn't have a 4 Ohm resistor so I twisted two 10 ohm resistors in parallel and it was about 5 Ohm so I figured it was close enough.  Not really sure I had to replace the speaker with anything, but figured it was likely in the circuit for a reason.  After the patch bay was installed and everything was still in pieces I masked off the text and gave the front a nice new paint job.  I love the new look of black keys for the white ones and red for the standard black ones. 

I ran random pins from the memory chips to the patch bay and added pitch and poly mods from the "Circuit-Bending : Build Your Own Alien Instruments" Reed Ghazala book. 

This thing is a drone artist's dream!  After about a minute I can have it self oscillating in bizarre directions, it's uncanny.  Now I just have to find one for myself.  :)  Samples are posted to my SoundCloud page. http://soundcloud.com/dyingtree/sk1-ramblings-01