Sequential Fourm – a compact 4-voice analogue synthesizer built on the legendary Prophet-5 architecture, combining vintage warmth with modern flexibility. Its dual oscillators allow simultaneous waveform selection, while a 4-pole resonant low-pass filter with bass compensation delivers the iconic Sequential character. The 37-note slim-key keyboard with polyphonic aftertouch provides expressive performance capabilities such as note bends and voice swells, making it highly responsive to nuanced playing. A knob-per-function layout and top-panel modulation matrix inspired by the Pro-One make sound design fast and intuitive, eliminating the need for menu diving. With 128 factory presets, an arpeggiator with sequencer mode, and rugged all-steel construction, Fourm is equally at home in the studio and on stage. Connectivity includes MIDI (in/out/thru), USB MIDI, and pedal inputs, ensuring seamless integration into any setup.
KEY FEATURES
- 37-note slim-key keyboard with polyphonic aftertouch for expressive playability
- 4 analogue voices with dual oscillators per voice and selectable waveforms
- Prophet-lineage 4-pole resonant filter with bass compensation
- Two ADSR envelopes, oscillator sync, and feedback drive for advanced sound shaping
- Pro-One style top-panel modulation matrix with colour-coded indicators
- 128 factory presets, arpeggiator and step sequencer with per-step glide
- Robust steel chassis designed for professional use
- Extensive connectivity: USB MIDI, MIDI in/out/thru, expression pedal input
TECHNICAL SPECIFICATIONS
- Keyboard: 37-note slim-key with polyphonic aftertouch
- Voices: 4 analogue voices, 100% analogue signal path
- Oscillators: 2 per voice, selectable waveforms, oscillator B with LFO modes
- Filter: 4-pole resonant low-pass with bass compensation and drive
- Envelopes: 2 × ADSR
- Sequencer: step sequencer with glide per step
- Presets: 128
- Outputs: main mono 1/4" jack, headphone out 1/4" TRS
- MIDI: in, out, thru; USB MIDI
- Pedals: footswitch/expression pedal input
- Power: 12V DC 1.2A adaptor (included), max 14 W consumption
- Construction: all-steel chassis with anti-theft slot
- Dimensions: 56.2 × 25.1 × 7.0 cm
- Weight: 3.97 kg






