SEQUENTIAL（Dave Smith Instruments） / Fourm

Fourm is a compact 4-voice analog synthesizer featuring polyphonic aftertouch that directly translates the nuanced touch of the performer's fingertips into sound.

Experience the joy of performance, the pleasure of shaping sound, and the freedom of expression like never before.

Fully equipped with a dual oscillator based on the Prophet-5, a traditional 4-pole low-pass filter, and the distinctive envelope curve modeled after the 1978 original. Adding overdrive feedback achieves the signature Sequential sound, combining warmth and power.

The Pro-One-inspired modulation matrix allows intuitive button-based assignments. Complex routing is easily managed with color indicators.

And the new Tactive? keybed, boasting unparalleled responsiveness, enables fresh expression. It will become a truly creative partner, bringing your musical ideas vividly to life.

Product Specifications
Synthesis
Each voice features two Prophet-5-style analog oscillators
All oscillators support simultaneous waveform selection (including LFOs)
Oscillator B supports low-frequency mode for polyphonic LFO modulation
Classic Prophet-style oscillator sync
Variable pulse width modulation (PWM) on each oscillator's square wave
4-pole resonant low-pass filter derived from Prophet-5 rev 1 & 2
Filter with bass compensation to maintain thickness even at high resonance
Capable of self-oscillation when resonance is increased
Filter keyboard tracking: 1/4, 1/2, full
Feedback with aggressive drive circuit
White/Pink/Violet noise selectable
4-stage (ADSR) filter envelope generator: for timbre changes (VCA) and modulation
4-stage (ADSR) amp envelope generator: for volume changes (VCA)
Velocity-sensitive envelope modulation for dynamic performance
One global LFO
7 LFO waveforms: Sine, Saw, Reverse Saw, Square, S/H (Sample & Hold), Noise, DC
LFO tempo sync with step value control
Simultaneously select up to 4 LFO waveforms for complex modulation
Enhancements
Simultaneously select up to 6 polyphonic aftertouch destinations
Polyphonic Aftertouch destinations: Oscillator A/B frequency, filter cutoff, amplitude (VCA), LFO frequency, LFO amount
Pro-One style top panel modulation matrix
2 modulation buses (multiple sources and destinations, plus bus synthesis possible)
Top panel modulation sources: Filter Env, Oscillator B, LFO
Top panel modulation destinations: Oscillator A/B frequency, Pulse width A/B, Filter cutoff, Amplitude (VCA), LFO frequency, LFO amount
Polyphonic Glide (Portamento)
Unison (Mono) Mode: Configurable for 1 to 4 voices, with chord memory
Vintage Mode: Reproduces component behavior fluctuations between voices
Arpeggiator (Supports Step Sequencer Mode)
Maximum 64 steps, polyphonic step sequencer with rest support
Sequencer supports Acid-style step glide
Sequencer can also be used as a modulation source
Hardware
Tactive? 37-key slim keyboard (supports polyphonic aftertouch)
100% analog signal path
Intuitive one-knob-one-function layout
Spring-loaded pitch wheel (variable range from 1 to 12 semitones per program)
Professional-grade all-steel chassis
Dimensions: 56.2 × 25.1 × 7.0 cm
Weight: 3.97 kg
Inputs and Outputs
Main Output Mono (1/4" jack)
Headphone Output Mono (1/4" TRS phone jack)
MIDI In/Out/Thru Ports
USB-C (Supports bidirectional MIDI communication)
Foot Switch/Expression Pedal Input
Pedal input also supports trigger and gate signals
Independent Power Switch
12 V DC 1.2 A Center-Positive Power Supply (Included)
Compatible with 100–240 V / 50 Hz - 60 Hz
Maximum Power Consumption: 14 W