doepfer-a-156

Doepfer A-156 Quantizer

Dual CV quantizer for scales, chords, and melodic grids

8 HP Eurorack module

The A-156 is a dual control voltage quantizer that converts any incoming analog voltage into the nearest musically useful stepped voltage, snapping free-running CVs to scales, chords, or intervals. Quantizer 1 offers a straightforward semitone grid while Quantizer 2 provides elaborate grid settings including major/minor scales, chords, fundamental+fifth, and optional sixth or seventh additions. A shared transpose input simultaneously shifts both quantizer outputs by a quantized semitone amount, making it ideal for generative melodic work, arpeggio-like patterns, and Theremin-style pitch correction.

Features

  • Dual independent quantizer channels
  • Quantizer 1: semitone (chromatic) grid by default, 1/12 V steps
  • Quantizer 2: elaborate grid settings — major/minor scale, major/minor chord, fundamental+fifth, with optional sixth or seventh addition
  • Jumper J1 on circuit board allows Quantizer 1 to share the same grid settings as Quantizer 2
  • Trigger inputs for synchronizing quantization to external events (LFO, sequencer clock, MIDI clock)
  • Quantization occurs at low/high transition of trigger signal when trigger input is used
  • Internal quantizing rate of approximately 500 Hz when trigger input is unpatched
  • Trigger outputs emit a 10ms pulse whenever a new quantization step occurs (output voltage changes)
  • Re-triggering: if a new trigger is needed within the 10ms pulse window, a 5ms pre-pulse appears before the next 10ms pulse
  • Shared transpose CV input simultaneously transposes both quantizer outputs
  • Transpose CV is quantized to the nearest semitone before being added to both outputs
  • Example: +1.0 V at Transpose input shifts both outputs one octave up

Controls & Jacks (25)

  • Quantizer 1 CV In— Control voltage input for Quantizer 1 to be quantized
  • Quantizer 1 CV Out— Quantized control voltage output from Quantizer 1
  • Quantizer 1 Trigger In— Trigger input to synchronize quantization of Quantizer 1 to external events
  • Quantizer 1 Mode
  • Quantizer 2 CV In— Control voltage input for Quantizer 2 to be quantized
  • CV
  • Quantizer 1 Trigger Out— Trigger pulse output whenever quantization occurs on Quantizer 1
  • Quantizer 2 CV Out— Quantized control voltage output from Quantizer 2
  • Quantizer 1 Scale Type— 3-position switch to select scale type for Quantizer 1: chromatic (All), major, or minor
  • Quantizer 2 Sixth/Seventh— 3-position switch to add sixth (+6) or seventh (+7) interval to chord/quint modes, or neither (-)
  • Switch 1 (Quantizer 1)— 3-position switch to select scale type for Quantizer 1: chromatic (All), major, or minor
  • Switch 2 (Quantizer 1)— 3-position switch to select output mode: Scale (all notes of selected scale), Chord (specific chord tones), or Quint (fundamental and fifth
  • Switch 3 (Quantizer 1)— 3-position switch to add sixth (+6) or seventh (+7) interval to chord/quint modes, or neither (-)
  • Switch 1 (Quantizer 2)— 3-position switch to select scale type for Quantizer 2: chromatic (All), major, or minor
  • Switch 2 (Quantizer 2)— 3-position switch to select output mode: Scale (all notes of selected scale), Chord (specific chord tones), or Quint (fundamental and fifth
  • Switch 3 (Quantizer 2)— 3-position switch to add sixth (+6) or seventh (+7) interval to chord/quint modes, or neither (-)
  • CV In 1— Control voltage input for Quantizer 1 to be quantized
  • CV Out 1— Quantized control voltage output from Quantizer 1
  • Trig. In 1— Trigger input to synchronize quantization of Quantizer 1 to external events
  • Trig. Out 1— Trigger pulse output whenever quantization occurs on Quantizer 1
  • CV In 2— Control voltage input for Quantizer 2 to be quantized
  • CV Out 2— Quantized control voltage output from Quantizer 2
  • Trig. In 2— Trigger input to synchronize quantization of Quantizer 2 to external events
  • Trig. Out 2— Trigger pulse output whenever quantization occurs on Quantizer 2
  • Transpose CV In 1+2— Control voltage input for simultaneous transposition of both Quantizer 1 and 2 outputs by semitone increments

How-To Guides

  • LFO Arpeggio with Minor Seventh
  • Analog Sequencer with Exact Tuning
  • Auto-Transposing Sequence with Dual Sequencer
  • Theremin Pitch Correction to Scale
  • Random Generative Melody in a Scale
  • Dual Voice Harmony
  • Envelope-Controlled Quantized Pitch Sweep
  • MIDI Keyboard Real-Time Transposition
  • Fundamental and Fifth Drone/Bass
  • Clock-Synced Scale Walking Bass Line

Explore the interactive A-156 Quantizer panel on BleepDex — tap any control to learn what it does.

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