Korg Volca Drum Physical Modeling Drum SynthesizerThe volca series is all about unique sound. Whether it's analog, PCM, or FM, the volca series puts unique sounds into an accessible platform. And now, the series is joined by a new rhythm machine that brings yet another sonic character. It's the volca drum digital percussion synthesizer. Based on a simple trigger waveform, wave folder and overdrive are used to add overtones and distortion, and then a waveguide resonator effect brings the sound to