Each D-50 sound ("patch") was made up of 2 "tones" (Upper and Lower) and each tone was made up of 2 "partials". Each partial could be either a "analog waveform" (pulse, sawtooth or sine waveform) and a VCF or a digital PCM waveform (sampled attack transient or looped sustain waveform). The partials could be arranged following 1 of 7 possible "structures" (algorithms), with a combination of either a PCM waveform or synthesized waveform, with an option to ring-modulate the two partials together. The synthesized waveforms could be pulse-width modulated and passed through an analog 4-stage Low-Pass filter, allowing for subtractive synthesis. The lower and upper part could be split or played in dual on the keyboard. The dual configuration allows an 8-voice polyphony bi-timbrality while only one partial plays, which allows for 32 voices.