Dave Smith Instruments Mopho x4 4-voice Analog Synthesizer 100% analog signal path Two oscillators per voice capable of producing sawtooth, triangle, saw/triangle, and variable pulse width square waves, with hard sync Two sub-octave generators per voice (one octave below oscillator 1 and two octaves below oscillator 2) One classic Curtis low-pass filter per voice (switchable 2- or 4-pole) with audio rate modulation, self-oscillating in 4-pole mode Analog VCAs