acl-sinfonion

ACL Sinfonion

Polyphonic harmonic hub for musical modular synthesis

42 HP Eurorack module

The Sinfonion is a comprehensive harmonic CV processor combining three independent quantizer channels, a four-voice chord generator, an arpeggiator, and a chord progression sequencer in one Eurorack module. It is designed for polyphonic, harmonically coherent modular music, allowing all voices to share a common musical key and scale while each section plays different intervals, enabling jazz-inspired chord progressions, modal scales, and complex voicings to be sequenced and performed live.

Features

  • Three independent quantizer channels (Channel 1, 2, 3) with selectable scale notes via musical interval buttons
  • Four-voice chord generator with 98 possible voicings, spread control, and inversions
  • Arpeggiator with 8 patterns (Up, Down, Up/Down, Down/Up, Baroque, Octaves, Brownian, Random), pitch, and range control
  • Chord progression sequencer with 16 songs, 4 parts each, up to 32 steps per part (2048 total steps)
  • 88 built-in base scales across multiple modes including Chords, Chords2, Slash chords, Major, Minor, Mel.Minor, Har.Minor, Har.Major, Db.H.Maj
  • All five sections share the same musical key and scale simultaneously
  • OLED display 128x64 pixels showing scale notes, chord structure, scale structure, or octave switches
  • 8 highly accurate 16-bit DACs with output range -2V to +8V
  • 16 highly accurate 16-bit ADCs covering -10.24V to +10.24V
  • Input and Output routing matrices (4x4 input mixing matrix, 4-to-4 output switching matrix)
  • Per-channel bypass modes: Normal Quantize, Soft Bypass (with transposition), True Bypass
  • Per-channel octave switches (+/-3 octaves range, 7 positions)

Controls & Jacks (60)

  • Arp 11th— Adjust chord voicing
  • Ch 2 3rd— Start/stop sequencer playback
  • Voicing Button 2— Adjust chord voicing
  • Ch 3 3rd— Increment step in sequence
  • Step Decrement Button 2— Decrement step in sequence
  • Ch 3 EQ-Dist 2— Cycle through sequencer modes
  • Ch 2 Fill 5— Select channel 1 for editing
  • Ch 2 11th— Select chord type
  • Arp 7th— Select step in sequence
  • Octave Up Button 2— Increment octave for channel 2
  • Ch 2 Spread— Decrement octave for channel 2
  • Octave Up Button 4— Increment octave for channel 4
  • Ch 3 Fill 2— Decrement octave for channel 4
  • Ch 2 13th— Select step in sequence
  • CV 2— CV input for master pitch modulation
  • Chords 13th— Increment step in sequence
  • Step Button Row 4— Select step in sequence
  • Chords INV— Select step in sequence
  • Ch 3 11th— Select step in sequence
  • Ch 3 EQ-Dist— Decrement step in sequence
  • Ch 3 Fill 3— Select chord type
  • Ch 3 Root— Cycle through sequencer modes
  • Arp Pattern
  • ADD— Increment step in sequence
  • Arp 3rd— Increment octave for channel 3
  • BEATS +
  • Ch 2 Fill 1— Decrement octave for channel 1
  • Ch 2 Root— Pitch control for channel 1
  • Ch 2 7th
  • Chords 3rd— Decrement octave for channel 3
  • Ch 3 9th— Select channel 4 for editing
  • Ch 3 13th— Select step in sequence
  • Chords 7th
  • MENU— Select channel 1 for editing
  • Ch 1 A/B— Select step in sequence
  • Ch 3 Fill 4
  • Ch 2 Trig— Gate output for channel 3
  • Chords 9th
  • Ch 3 7th
  • Ch 2 9th
  • Arp Root— Pitch control for channel 1
  • Chords 11th— Select step in sequence
  • Ch 3 In— Reset input to restart sequences
  • Chords Slew— Internal tempo control
  • Octave Up Button 1— Increment octave for channel 1
  • Arp 5th
  • Ch 2 In— Quantized pitch output
  • Arp 13th
  • Ch 1 7th
  • Channel 2 Pitch CV Input— CV input for channel 2 pitch modulation
  • Ch 3 5th— Select channel 3 for editing
  • Chords 5th
  • Ch 1 11th
  • Arp 9th
  • Root— Set the root note of the chord
  • Ch 1 Fill— Adjust chord voicing
  • Arp Begin— Adjust chord voicing
  • Ch 1 13th
  • Ch 1 In— CV input for channel 1 pitch modulation
  • Ch 1 A/B— Pitch CV output for channel 4

How-To Guides

  • Save Button Preset
  • Load Button Preset
  • Factory Reset
  • Reset Menu Settings to Defaults
  • Create a Jazz Chord Progression
  • Modal Bass Line with Arpeggiator
  • Evenly Distributed Random Melody
  • Harmonic Complexity Builddown Effect
  • Evolving Polyphonic Pad with Spread and Vibrato
  • Two-Sinfonion Linked Performance
  • CV-Sequenced Chord Voicing Melody
  • Requantize and Transpose External Sequence

Explore the interactive Sinfonion panel on BleepDex — tap any control to learn what it does.

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