sure. basically, i hooked up an APC, to use as an oscillator. i found that some of the sounds of the apc counteract with the notes on the keyboard.
also, the voltage sweep of the apc on certain settings seems to filter the sounds of the keyboard. that is the best way i can explain it, with what i know (or lack thereof).
i also added a power crash, a dc adapter jack, a 5th switch, an 8th switch (octave), a body contact (which is not working, i need to find out why, it worked before), an output phone jacka custom paint job.
it's funny, something which is not discussed much, are the automated sounds on these keyboards. i mean, people do talk about the drum sounds, but there are some cool arpedgiated tones! i love the COMPUTER sequence on this! it sounds even cooler when effected by the oscillator!
samething with the sk1. the drums and other sounds get bastardized nicely with the oscillator and the patch bay! ;-)