Sequential Fourm - 4-Voice Analogue Synth with Polyphonic Aftertouch

Sequential is aiming to capture the affordable polysynth buyers with the announcement of Fourm, a new four-voice analog synthesizer featuring a custom-designed polyphonic aftertouch keybed and a modulation interface inspired by the Pro~One (Pro~Four surely?).

Poly aftertouch has been missing from the Sequential line-up for some time - we think the last time was the Prophet T8?

Fourm combines a two OSC subtractive architecture with expressive control, and at a relatively affordable price which is £849/€ 949 - yeah not bad eh?

Four fully analogue voices are derived from the architecture of the original Prophet-5, including dual oscillators, a 4-pole lowpass filter, and envelope curves modelled. Added overdriven feedback routing can give the  a bit more edge.

There's a  new Tactive™ slim-key polyphonic aftertouch keybed, developed in-house by Sequential. It was co-designed with Fourm's analog engine to provide an expressive connection between player and instrument. Sequential says the decision to build a custom keybed was made because "no off-the-shelf keybed could deliver" the desired experience.

The modulation section draws inspiration from the Pro~One, offering a top-panel modulation matrix that avoids the need for menu diving. Sources and destinations s are managed with button presses and colour-coded indicators for visual feedback.

Key Features:

• Four analog voices based on the Prophet-5 architecture

• Dual VCOs per voice and classic 4-pole lowpass filter

• Tactive™ polyphonic aftertouch slim-key keybed

• Overdriven feedback for added tonal edge

• Hands-on modulation matrix with colour-coded interface

• Compact, performance-friendly design

We'll be getting our hands on this shortly so expect a review from us.

https://sequential.com/modern-analog/fourm/

• SonicLAB: Sequential FOURM Review 13-Oct-25
• Sequential Take 5 Desktop Module Is Here 01-Jul-25
• Sequential Introduces Prophet-10 Special Edition 22-Oct-24
• Goodbye Prophet X 03-Apr-24
• Synthfest UK 2023: Calc And the Prophet X 09-Oct-23