A vampirically powered drum machine!

The MIDIvampire-II is a 4 voice drum machine that is powered from the MIDI data line. It has 2 wavetable voices for making kick drums, toms, wood blocks, bells, and a host of other sounds. There is a voice set aside for hi-hats and cymbals, and another which is a filtered noise source, which can make snares and hollow-tube sounds. Each voice has separate attack, decay, and release, along with frequency sweep, and a bunch of other effects for warping the sounds to fit all your percussive needs. And, there are independent outputs for each voice.

All of the documentation, including the MIDI implementation is up on the MIDIvamp Wiki. And, if you want to pick one up, swing by the store and have a look.