Casio SK1 keyboards are the ne plus ultra of circuiting bending instruments. They have dozens of points on the pcb to mess with the audio signal (digitally). To access these points and connect them toegther in interesting ways, it is highly desirable to use banana jacks.

This is a plate with a series of holes for mounting banana jacks into the speaker cavity of a Casio SK-1 keyboard. You'll have to cut the speaker grill out (it is a messy job). I suggest mounting the plate first so you can avoid cutting where the four screw holes are supposed to be. Also includes two larger holes for mounting small pots that can be connected to the bottom two banana jacks in series. All holes may print a little small, so be sure to have a reamer on hand to allow parts to fit.

Happy circuit bending! :)