 The JD-800 combines sample playback with digital synthesis, a process that Roland calls Linear Arithmetic synthesis, a technique Roland had been using to great effect in the Roland D-50.The JD-800 has 108 waveforms built-in, but these can be expanded via PCM-cards.There are waveforms in a variety of categories, like; analog synth, acoustic instruments, like guitars, woodwind, brass and voices.