Sequential Fourm 4-Voice Analog Synthesizer - Ex Demo

Full Description

Factory Bank 2 - now available for download

Breathing new life into the Fourm, Sequential has released the Factory Bank 2 - a brand new collection of contemporary sounds created by respected designers Abby Echiverri, Peter Dyer, Glasys, Nicholas Semrad and Calc. Also available is a Pro-One-inspired sound bank of 40 presets by Drew Neumann. Comprised of 128 new presets, the Factory Bank 2 takes your total preset count up to 256 - giving you all the inspiration you need to create something special. These banks adds even more modern flavour to the instrument with a huge range of new presets to inspire and push your boundaries.

Classic Sequential tone, reimagined for today

At the core of the Sequential Fourm lies a four-voice analog architecture that stays true to the heritage of the Prophet-5. The signal path is 100 percent analog, with envelope response curves modelled directly after the original design. This ensures that Fourm captures the musical feel and responsiveness that defined early Sequential instruments.

Each voice features two oscillators with simultaneous waveform selection. Unlike traditional analog synthesizers that restrict you to a single waveform at a time, Fourm allows you to blend waves freely for a richer harmonic palette. Oscillator B includes a low-frequency mode for modulation duties, adding even more flexibility. The classic oscillator sync function is also present, enabling harmonically complex and dynamic textures.

The analog filter section is a 4-pole resonant low-pass design, updated with bass compensation to preserve low-end energy when resonance is increased. This means you can push the resonance without losing power in the bottom end, making the filter more usable across a wider range of tones. The result is an instrument that feels both familiar and modern, capable of smooth vintage tones or more aggressive contemporary sounds.

Expressive playing with polyphonic aftertouch

One of the standout features of the Fourm is its 37-note slim-key keyboard with polyphonic aftertouch. Unlike traditional aftertouch systems that respond to pressure across the entire keyboard, polyphonic aftertouch responds to pressure on each individual note. This allows for incredibly detailed performance expression, such as applying vibrato to one note while holding another steady, or swelling certain notes in a chord without affecting the rest.

This level of control opens up new playing techniques and adds a layer of expression that is rarely found in compact analog synthesizers. Whether you are performing solo melodies or chordal textures, the Fourm responds to every nuance of your touch, bridging the gap between keyboard and instrument in a truly expressive way.

Modulation made visual and intuitive

The modulation matrix on the top panel of the Fourm draws inspiration from the legendary Pro-One, offering a hands-on and immediate approach to sound design. Instead of digging through menus, you can route modulation sources to destinations directly on the panel. Visual feedback is provided through colour-coded indicators, making it easy to see how each element of your patch is interacting in real time.

You can assign envelopes, LFOs, aftertouch, velocity and more to parameters like filter cutoff, oscillator pitch or wave shape. This setup allows you to build evolving, dynamic patches quickly, with a focus on creativity and playability. The intuitive layout encourages experimentation and keeps your attention on the sound, not the screen.

Built to perform, designed to last

Despite its small size, the Fourm is housed in a rugged steel chassis that feels solid and professional. The layout is clean, with a knob-per-function design that keeps every control within easy reach. It includes 128 factory presets that cover a wide range of sounds, from vintage leads and lush pads to evolving textures and percussive sequences. These can be used as-is or serve as starting points for your own creations.

An onboard arpeggiator with sequencer mode adds rhythmic and melodic variation, making Fourm suitable for standalone use or integration into larger setups. You can trigger patterns, tweak sequences and interact with your sounds in real time. This makes Fourm not just a studio tool, but a performance-ready instrument.

Flexible connectivity for modern setups

Fourm is equipped with MIDI In, Out, and Thru ports, as well as USB for bi-directional MIDI communication with your computer or DAW. It also includes a 1/4-inch mono main output and a separate headphone output for private monitoring. An expression pedal input allows for real-time control of parameters such as filter cutoff or volume, adding yet another layer of interaction.

Power is supplied via an included 12V DC adapter, and the unit features a dedicated power switch. With a maximum power consumption of just 14 watts, it is efficient and easy to integrate into any workspace or live rig. Whether you are in the studio, on stage or on the move, the Fourm provides a powerful and expressive synthesis experience in a highly portable form.

Features

• Compact four-voice analog synthesizer built on the Prophet-5 voice architecture
• Dual oscillators with simultaneous waveform selection and classic sync for rich tone shaping
• 4-pole resonant low-pass filter with bass compensation for added warmth and clarity
• 37-note slim-key keyboard with polyphonic aftertouch for expressive performance control
• Hands-on modulation matrix with button-based routing and colour-coded visual feedback
• Intuitive knob-per-function interface for immediate sound design without menu diving
• Built-in arpeggiator with sequencer mode and per-step glide support
• Feedback circuit with aggressive drive for added harmonic character
• Includes 128 factory presets covering a wide range of sounds
• USB and full-size MIDI in, out, and thru ports for flexible connectivity
• Mono main and headphone outputs plus expression pedal input
• Durable all-steel chassis for professional, road-ready reliability
• 12V DC power supply included, compatible with global voltage standards

Specifications

• Dimensions (L X W X H): 22.13" X 9.88" X 2.75" (56.2 Cm X 25.1 Cm X 7.0 Cm)
• Weight: 8.76 Lbs (3.97 Kg)
• Product Code: SEQ-3900