Dave Smith Instruments Mopho x4 Analog Synthesizer (Discontinued)


93 out of 100. Incorporating 90+ ratings and reviews.

Street Price: 

Dave Smith Instruments Mopho x4 Analog Synthesizer

Gearank High Notes

The Mopho x4 from Dave Smith Instruments features 4-voice polyphony with an all analog signal path.

Each of those four voices exhibits dual oscillators, two sub octave generators, four LFOs, an arpeggiator, a Curtis low-pass filter, three envelope generators, and a gated 16 x 4 step sequencer.

This analog synthesizer comes with a full-sized 44-note pressure-sensitive keyboard and free assignable pitch and modulation wheels.


  • Keys: 44-note velocity sensitive semi-weighted keyboard
  • Polyphony: Polyphonic: 4 notes
  • Oscillator: 2 x oscillators per voice, 2 x sub-octave generators per voice (one octave below oscillator 1 and two octaves below oscillator 2)
  • Filter: 1 x Curtis low-pass filter per voice (switchable 2- or 4-pole) with audio rate modulation, self-oscillating in 4-pole mode
  • Envelope: 3 x envelope generators per voice
  • LFO: 4 x LFOs per voice
  • Additional Controllers: Pitchbend, Mod Wheel
  • Presets: 512
  • Step Sequencer: 16 x 4 step sequencer per voice
  • Audio Input: None
  • Audio Output: 2 x 1/4″ TS phone jack, 1/4″ TRS headphone out
  • Other Connectivity: 1/4" Sustain pedal input, 1/4″ Expression pedal/CV input, MIDI In, Out/Thru, and Poly Chain
  • Power: 100V – 240V AC operation
  • Dimensions: 25.2″ x 11.1″ x 3.6″
  • Weight:13.5 lbs


Both experts and users were more than satisfied with its responsive keyboard and retro design. Its rigid knobs and controls are laid out in a sensible way that gives users an instant access to the parameters. In his Sound on Sound review, Paul Nagle mentioned the stored factory presets offered "countless (at least I didn't count them) solo patches of the in-your-face and searing type, and rather fewer of the flowery, new age sort. Pads and strings are lush and tasty, and as for bass, those sub-oscillators could add rumbling nuances to any track." The unit's four LFOs provided various modulation options to its two stable sounding oscillators, letting musicians create complex sounds and store their own personalized patches.


Some users pointed out its lack of audio inputs, though a MIDI Input and a Poly Chain lets users connect to other Dave Smith Instruments and MIDI equipment for layering sounds. Arpeggiator and sequencer editing sections aren't present on the front panel itself, but it can be edited via editing software.


For a reasonable price, this is an exceptional choice if you are looking for a unit with massive signal and modulation routing capabilities.

Unfortunately it's no longer widely available new, so you might like to look at some alternatives in our guide to The Best Synthesizer Keyboards.