Special Order - Estimated 1 Week Turn Around - Reserve Yours Now
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 generation—and takes it to the next level.
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’sanalog 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.
Polyphonic aftertouch is one of Fourm’smost expressive features, offering a direct and nuanced connection between your playing and per note synthesis parameters. It opens up new possibilities for articulation — from subtle dynamics to dramatic gestures — that go far beyond what’spossible with other high performance musical instruments and controllers.
Because polyphonic aftertouch is still relatively uncommon, there’s not much guidance out there on how to use it effectively. That’s why we’ve put together a list of techniques — and you don’t need to be a virtuoso player to benefit. This guide is for anyone curious about what polyphonic aftertouch can bring to their music.
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.
- 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
- Up to six polyphonic aftertouch destinations selectable simultaneously
- Polyphonic aftertouch destinations: oscillator A frequency, oscillator B frequency, filter cutoff, amplitude, LFO frequency, LFO amount
- Pro-One style top-panel modulation matrix
- Two modulation buses with multiple sources and destinations and the ability to combine both buses at the destination
- Top panel modulation sources: filter env, oscillator B, LFO
- Top panel modulation destinations: oscillator A frequency, oscillator B frequency, pulse width A, pulse width B, filter cutoff, amplitude, LFO frequency, LFO amount
- Polyphonic glide (portamento)
- Unison (monophonic) mode with configurable voice count, from one to all four voices, plus chord memory
- Vintage setting recreates classic synth characteristics by adding voice-to voice variations in component behavior
- Arpeggiator with step sequencer mode
- Polyphonic step sequencer with up to 64 steps and rests
- Sequencer supports acid-style glide per step
- Sequencer can be used as a modulation source
- Tactive™ 37-note slim-key keyboard with polyphonic aftertouch
- 100% analog signal path
- Intuitive, knob-per-function layout
- Spring-loaded pitch wheel with selectable range per program (1 to 12 semitones up and down)
- Pro-quality, all-steel chassis
- 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)
- Main output mono (1/4” jack)
- Headphone output mono (1/4” TRS phone jack)
- MIDI in, out, and thru ports
- USB-C for bidirectional MIDI communication
- Footswitch/expression pedal input
- Pedal input also supports trigger and gate signals
- Separate power switch
- 12V DC 1.2A power supply, center-positive (included)
- Power supply 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
Condition: New
Info from Sequential