Sequential Fourm

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.

FEATURES

• 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 

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.

SPECIFICATIONS

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