Legendary Analog Sound, Reimagined
Fourm delivers four genuine voices of Sequential analog sound, built on the legendary Prophet-5 voice architecture—right down to its envelope response curves. With dual oscillators offering simultaneous wave selection and a classic 4-pole low-pass filter, now enhanced with bass compensation, Fourm captures the warmth and punch that shaped a generation—and takes it to the next level.

A New Fourm of Expression
Fourm’s 37-note slim-key keyboard features polyphonic aftertouch, unlocking expressive techniques like guitar-style note bends, solo voice swells, and other nuanced articulations—completely transforming the experience of playing a modern analog polysynth.

Modulation You Can Touch
Inspired by the Pro~One, Fourm’s top-panel modulation matrix puts deep sound design at your fingertips—no menu diving required. Route sources and destinations with a button press, visualize connections with color-coded indicators, and build complex modulation paths in seconds. It’s fast, intuitive, and designed to keep you in the creative flow.

Warranty: One-year warranty included
Wherever you are in the world, all Sequential hardware comes with a one-year warranty to cover any necessary repairs or replacements due to manufacturing faults.

Technical Specifications

• 37-note slim-key keyboard with polyphonic aftertouch
• Warm and organic, 100% analog signal path
• Intuitive, welcoming knob-per-function layout
• Pro-One style top-panel modulation matrix
• Prophet-lineage resonant filter with bass compensation
• Arpeggiator with sequencer mode
• 128 world-class presets
• Pro-quality, all-steel chassis

SYNTHESIS

• All oscillators have simultaneously selectable waveforms – LFO too
• Oscillator B supports low frequency modes
• Classic Prophet-style Sync
• 4-Pole resonant lowpass filter
• Feedback with aggressive drive circuit
• 2 ADSR envelopes
• Sequencer supports glide per step

IN/OUT

• Main output mono (1/4” jack)
• Headphone output mono (1/4” TRS phone jack)
• MIDI in, out, and thru ports
• USB for bidirectional MIDI communication
• Footswitch/expression pedal input

POWER

• Separate power switch
• 12V DC 1.2A power supply, center-positive (included)
• Can be plugged into an AC outlet capable of supplying from 100 V to 240 V at 50 Hz/60 Hz.
• 14 Watts maximum power consumption.

PHYSICAL SPECS

• 22.13" L x 9.88" W x 2.75" H (56.2 cm x 25.1 cm x 7.0 cm)
• Weight: 8.76 lbs. (3.97 kg)
• Anti-theft slot