Fourm is a compact analog synthesizer that invites you to play, shape, and perform with unprecedented expression. With its legendary Sequential tone, hands-on modulation, and uniquely responsive keybed, Fourm is a creative partner helping to bring your musical ideas to life.
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.
FEATURING
• ​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