Sequential Fourm 4-Voice Analog Synth with Polyphonic Aftertouch

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 Tactive™ keybed, Fourm is a creative partner helping to bring your musical ideas to life.

Fourm delivers four genuine voices of Sequential analog sound, built on the legendary Prophet-5 voice architecture-right down to its characteristic envelope response curves. With dual oscillators offering simultaneous wave selection and a classic 4-pole low-pass filter with bass compensation, Fourm captures the warmth and punch that shaped a generationand takes it to the next level.

A New Fourm of Expression
From its solid steel chassis to the custom-engineered Tactive slim-keys keybed with responsive polyphonic aftertouch, every element of Fourm was designed to deliver a fully integrated, high-performance playing experience. It's a no-compromise, all-analog instrument, built for the next generation of synthesists.

Custom-designed by Sequential, the Tactive™ keybed features 37 slim-keys tuned specifically to complement Fourm's analog synthesis engine. And for the first time in 40 years, Sequential has returned to polyphonic aftertouch, an incredibly expressive performance feature that brings per note articulations to your fingertips.

Hands on modulation
Fourm's modulation section is inspired by the legendary Sequential Circuits Pro-One, a highly sought-after classic monosynth that has propelled the bass lines of synthpop for decades. Explore the immediacy and flexibility of this hands-on modulation matrix and let your latest sonic inspirations take Fourm.

Fourm's arpeggiator responds to your playing with inspiring musical results. Need a three octave setting with a dotted 8th note step value to create cascading, syncopated patterns? Fourm can do that and more. With re-latching, repeat settings, and six modes of interaction, the arpeggiator is a powerful tool for spontaneous composition and performance.

Features

• Two Prophet-5 lineage analog oscillators per voice
• All oscillators have simultaneously selectable waveforms, including the LFO
• Oscillator B supports low frequency modes for use as polyphonic LFO modulation
• Classic Prophet-style Sync
• Variable square wave pulse width per oscillator (PWM)
• 4-Pole resonant lowpass filter drawn from the Prophet-5, revs 1 & 2
• Filter enhanced with bass compensation for thick sounds even with high resonance
• Filter can be driven into self-oscillation with the resonance control
• Filter Keyboard tracking: quarter, half, full
• Feedback with an aggressive drive circuit for extra edge
• White, pink, and violet Noise types allow for greater sonic variation
• Four-stage (ADSR) filter envelope generator for tone shaping and assignable modulation
• Four-stage (ADSR) Amp envelope generator for volume shaping
• Velocity modulation of envelope amounts for dynamic performance
• One global LFO for creating movement in the sound
• Seven LFO wave shapes: sine, sawtooth, reverse sawtooth, square, S/H (sample and hold), Noise, and DC
• LFO can synchronize to tempo at different step values
• Four LFO wave shapes can be selected simultaneously for complex modulations