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Sequential Fourm Compact Analog Synthesizer

Fourm's 37-note slim-key keyboard features polyphonic aftertouch, unlocking expressive techniques like guitar-style note bends, solo voice swells, and other nuanced articulations.

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    Legendary Analog Sound, Reimagined

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

     

    A New Fourm of Expression

    Fourm’s 37-note slim-key keyboard features polyphonic aftertouch, unlocking expressive techniques like guitar-style note bends, solo voice swells, and other nuanced articulations—completely transforming the experience of playing a modern analog polysynth.

     

    Modulation You Can Touch

    Inspired by the Pro~One, Fourm’s top-panel modulation matrix puts deep sound design at your fingertips—no menu diving required. Route sources and destinations with a button press, visualize connections with color-coded indicators, and build complex modulation paths in seconds. It’s fast, intuitive, and designed to keep you in the creative flow.

     

    One-year warranty included

    Wherever you are in the world, all Sequential hardware comes with a one-year warranty to cover any necessary repairs or replacements due to manufacturing faults.

     

    Sequential Fourm Compact Analog Synthesizer Features:

    • 37-note slim-key keyboard with polyphonic aftertouch
    • Warm and organic, 100% analog signal path
    • Intuitive, welcoming knob-per-function layout
    • Pro-One style top-panel modulation matrix
    • Prophet-lineage resonant filter with bass compensation
    • Arpeggiator with sequencer mode
    • 128 world-class presets
    • Pro-quality, all-steel chassis

    CALIFORNIA PROPOSITION 65 WARNING

    WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov.

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    Sequential Fourm Compact Analog Synthesizer Specifications

    Sequential Fourm Compact Analog Synthesizer Specifications
    Product Specifications
    • Synthesis: 
      • All oscillators have simultaneously selectable waveforms – LFO too
      • Oscillator B supports low frequency modes
      • Classic Prophet-style Sync 
      • 4-Pole resonant lowpass filter
      • Feedback with aggressive drive circuit
      • 2 ADSR envelopes
      • Sequencer supports glide per step 
    • IN/OUT: 
      • Main output mono (1/4” jack) 
      • Headphone output mono (1/4” TRS phone jack) 
      • MIDI in, out, and thru ports
      • USB for bidirectional MIDI communication 
      • Footswitch/expression pedal input 
    • Power: 
      • Separate power switch 
      • 12V DC 1.2A power supply, center-positive (included)
      • Can be plugged into an AC outlet capable of supplying from 100V to 240V at 50 Hz/60 Hz.
      • 14W maximum power consumption. 
    • Physical Specs:
      • Dimensions (L x W x H): 22.13" x 9.88" x 2.75" / 56.2 x 25.1 x 7.0 cm
      • Weight: 8.76 lbs / 3.97 kg
      • Anti-theft slot
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