i got one of these in recently:
aah. cheese.
it came with the question if it was possible to have separate triggers and outputs for all the sounds, possibly individual volume controls etc. foolishly, i gave my standard answer ("sure!") before realising there was no such thing as a free interweb-floating schematic of this thing. nooo infooo whatsoooever.
so yes, i set about doing just that.. tracing the fucker.
partial schemo below. didn't do the bottom board, which is the rhythm and pattern generator. you're on your own there.
so 6 hours later, it turns out there's 4 twin T based oscillators (kick, tom1, tom2, claves) and 2 filtered noise sounds (hh and snare.)
the hh has a long and short option. the snare always triggers tom1 with it to add some bottom end, and includes an LFO in it's trigger circuitry that allows for drum rolls. note that that means the rolls have a fixed tempo, as in: not a division of the master tempo. just let it go fast enough, no one'll ever know. nifty. i would think that also means that snare triggers have to be short enough so as to allow for less than a full LFO cycle, to avoid double hits.
when tom1 is used on its own (in exactly 2 presets), it's made slightly longer - in a vain attempt to set it apart from the snare sound, i would guess. oh, and there's an accent trigger on the output amp.
good modding news: there's prefab trimmers for oscillator gains (usable as length controls), volumes and roll speed.
twin T oscillators are not the friendliest to throw in a pitch control, but i hope to manage that by using dual ganged pots replacing the series resistors in the first of the T's. hope to manage additional manual triggers for kick, snare and hh (complementing the funky Big Buttons already there.)
the real fun starts when you start crossbending what is essentially crude data lines - using the trigger line for the samba clave rhythm on the kick, for example. here's a quick and dirty example of that. i think it sounds gorgeous.
