Sequential FOURM

A Compact Heir to the Prophet Lineage

Fourm adopts the sound architecture and envelope curves that made the Prophet series famous, in a portable format designed for modern musicians. Its fully analog signal path and resonant filter deliver that punchy and warm character that has defined generations, while adding bass compensation to preserve the low-end foundation at high resonance.

Who Is It For and What Are Its Uses?

Ideal for keyboardists and producers seeking a versatile and expressive analog synth. Perfect for live performance and studio work in electro, techno, synthwave, pop, ambient, or sound design for visuals. Motivated beginners will appreciate the "one function per control" layout, while advanced users will exploit the polyphonic aftertouch and advanced modulation options for nuanced performances.

Technical specifications

Arpeggiator	Yes	Sound generator	VCO
Controller	Pitchbend, Scroll wheel, Sustain	Envelope	ADSR
Filters	Resonant low-pass filter, 4-pole, 24 dB/octave, inspired by the Prophet-5	LFO	1
User memories number	512	Accessories included	Power supply
Max polyphony	4	MIDI I/O	IN, OUT, THRU (DIN), MIDI PAR USB
Velocity sensitive	Yes	Inputs	Expression pedal, Midi, Footswitch, USB Midi
Number of oscillators	2	Outputs	Midi, Headset, Jack, USB-C, USB Midi
Synthesis type	Analog, Subtractive	Color	Black
Category	Analog synth	Finishing	Steel
Number of keys	37	Sequencer	Yes
Touch	Dynamic with polyphonic aftertouch	Preset number	512
Key format	medium	Display	OLED
Transposition	Yes	Weight	3.97 kg
Aftertouch	Yes	Dimensions (mm)	562 x 251 x 70

Keyboard	slim, 37 keys with polyphonic aftertouch	Sequencer glide	per step
Signal path	fully analog	Main input	mono, 1/4" jack
Control layout	one function per control	Headphone output	mono, 1/4" TRS jack
Modulation matrix	front-panel, inspired by the Pro-One	MIDI connectivity	input, output and Thru
Filter design	resonant, in the Prophet tradition, with bass compensation	USB MIDI port	bidirectional
Number of presets	128	Pedal input	expression/footswitch
Oscillator and LFO waveforms	simultaneous selection on all oscillators and LFOs	Power switch	separate
Oscillator B	can also be used as an LFO	Power supply included	12 V DC, 1.2 A, center-positive
Synchronization	classic, as on the Prophet	Compatible mains power	100 V to 240 V AC, 50 Hz/60 Hz
Filter type	4-pole resonant low-pass	Maximum power consumption	14 watts
Feedback	with drive circuit	Dimensions	562 mm L x 251 mm W x 70 mm H (22.13" x 9.88" x 2.75")
Envelopes	2 ADSRs	Anti-theft compatibility	Kensington security