PAPERBIRD
​纸鸢

Paperbird is a versatile utility module built around two square-wave generators that cross-modulate to unlock a wide range of functions. Each function can also process external signals by patching into the corresponding jacks, replacing the internal square waves.

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Core Controls

• A / B Knobs: Adjust the rate of the two internal square waves

• A / B CV Inputs: Modulate the square wave rates with external CV

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Functions (Top to Bottom)

1. Logic

• Internal square waves A & B are normalled to inputs A and B

• Patch into A or B to replace internal signals with external audio/CV

• OR Output: Logical OR of the two inputs

• AND Output: Logical AND of the two inputs

• Bonus: Feeding audio signals converts them into square waves at the outputs

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2. Shifting Register

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• Two independent shift register sections:

   

  • Top: A = Clock, B = Data

  • Bottom: A = Data, B = Clock

   

• External signals can replace A/B

• Outputs per section:

   

  • DC1 / DC2: Stepped voltages via R-2R DAC

  • AC1 / AC2: Smoothed versions of DC outputs for flowing modulation

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3. VCA + Wavefolder

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• AC1 / AC2 feed into signal inputs

• A / B feed into control inputs

• Patch external signals for either input

• Behavior:

   

  • Low control signal → acts as VCA

  • Higher control → signal folds beyond threshold

  • Adjust controls for pure VCA, pure wavefolder, or hybrid shaping

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4. Mixer

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• Three-channel mixer with:

   

  • MIX & MIX MULT: Mixed signal

  • -MIX: Inverted mix

   

• Fully independent; no internal routing

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Rear Panel Trim Pots

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• 2 × Smoothing for AC outputs

• 2 × Fold thresholds for wavefolders

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Birdance – 4HP Expander

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Connect via the rear header for extended features:

• A / B Individual Outputs (raw square waves)

• Extra CV inputs for the two VCAs (normalled to +6V with attenuators)

• Offset Generator: Adjustable -6V to +6V CV source