Sequential Fourm 4-Voice Analog Synthesizer w/ Polyphonic Aftertouch

The Sequential Fourm is a compact, expressive 4‐voice analog synthesizer with polyphonic aftertouch, designed to inspire creativity. Combining iconic Sequential tone, hands‐on modulation, and a uniquely responsive keybed, Fourm transforms musical ideas into fully realised performances.

Built on the legendary Prophet‐5 voice architecture, Fourm delivers four true analog voices with the warmth and punch that defined a generation. Dual oscillators with simultaneous wave selection and a 4‐pole resonant lowpass filter with bass compensation ensure every note is rich, dynamic, and full of character.

The 37‐note slim‐key keyboard with polyphonic aftertouch unlocks expressive techniques such as note bends, swells, and nuanced articulations. A Pro~One‐inspired top‐panel modulation matrix puts deep sound design at your fingertips, with visual feedback from colour‐coded LEDs and immediate routing ‐ no menu diving required.

Features

• 4‐voice true analog signal path with Prophet‐lineage tone
• 37‐note slim‐key keyboard with polyphonic aftertouch
• Dual oscillators with simultaneous waveform selection (LFO included)
• Oscillator B supports low‐frequency modes
• Classic Prophet‐style sync
• 4‐pole resonant lowpass filter with bass compensation
• Feedback with aggressive drive circuit
• Pro~One‐style top‐panel modulation matrix with colour‐coded LEDs
• Two ADSR envelopes
• Arpeggiator with sequencer mode and glide per step
• 128 factory presets
• Mono main output (1/4" jack) and mono headphone output (1/4" TRS)
• MIDI In, Out, Thru and USB MIDI
• Footswitch/expression pedal input
• Pro‐quality steel chassis
• Includes 12V DC 1.2A power supply (100‐240V AC compatible)