Cassa has two trigger inputs between which you can crossfade unsing the MIX potentiometer. So simple and so brilliant ... mix two different trigger sequences, blend between them, create fill-ins or connect a manual gate and fire some extra drums with your finger!
FREQ sets the drum frequency, RES controls decay time; at long decays the Cassa starts oscillating in an obscure way and starts screaming (no, it's no self- oscillation, that's schreaming!). DIST is a pretty wild distortion. Gabba musicians will love it!
Attention: module abuse!:
As the module is based on a filter which resonates when being "pinged" by a trigger signal at the audio input and then creates a percussive sound it's not far-fetched to inject audio signals instead triggers int othe Cassa. FREQ is cutoff frequency and RES the filter resonance, just as expected. But both act pretty unusual in this case for a filter. It phases more than it filters, the resonance roars and the distortion does the rest...
Instead of using two audio signals you might use one trigger and one audio signal - and the Cassa will indeed generate a drum and process the audio signal at the same time. Weird but possible. Instantly it was possible to generate a wobbly Skrillex simulation, read: saw mill dubstep aka "Filth".
2x input, 1x audio output
3U Eurorack module, 4HP wide, 26mm deep