The space drum is amazing alone. Are you looking for a similiar device or a schematic? The space drum is more of an analog synthdrum, not really a circuitbendable toy.
if i had the real space drum, id be afraid to even use it. this image
makes me shudder. i just want a touch sensitive drum pad thing. then ima add it to a circuit bent toy. so if you were going to make your own space drum, what part would you use for the pad?