Here's a layout for Synthbox, a very nice octave down.
It's based on Joe Davisson's Shocktave.
I built it today so it's verified.
I found the schematic in a very long thread discussing the original Shocktave.
It's basically a bunch of mods put together to make it cleaner and track better.
It's a great improvement on the original and more "synthy" sounding.
It tracks really well except the high e-string which doesn't always register.
I will make a demo when I have finished boxing it.
check out my building blog at www.parasitstudio.se