The term "digital" typically brings to mind sounds that are based on PCM-sampled bass drum, snare drum, or cymbal, but the volca drum creates its drum sounds by DSP-powered analog modeling. Oscillator waveforms such as sine wave, sawtooth wave, and noise are provided. By applying various changes to these waveforms, you can create a wide variety of percussion sounds that range from realistic to idiosyncratic, and are not limited only to drums. The six parts each have two layers, and do not impose any rules or restrictions such as specifying which parts must be used for the bass drum or for the cymbal; all parts have the same specifications. You can freely assign your new sounds to these six parts without being limited by the conventions of a drum set. A kit consists of the six parts that you've assigned plus the waveguide resonator effect settings, and 16 such kits can be stored in memory (the factory settings contain 10 preload kits). Each part consists of two layers. For each layer, users choose one of five types of oscillator waveform including sine wave, sawtooth wave, and HPF noise, and also choose from three types of pitch modulator and amp EG, each optimized for drum sounds. You can customize the resulting trigger waveform by applying bit reduction to produce roughness, adjusting the wave folder depth to add complex overtones, and using overdrive to adjust the distortion. In this way, you can generate distinctive sounds from this sound engine that's structured rather differently from a typical drum machine. The effect section features a waveguide resonator that's based on physical modeling, and which adds sympathetic resonances to the sound.