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Maddie MOD2
VCO
Oscillator
A six-waveform oscillator with PolyBLEP anti-aliasing and negative-slope 1V/oct CV.
- Width
- 4 HP
- Depth
- 28 mm
- Power
- +12V / −12V / +5V
- MCU
- Seeed XIAO RP2350
- Controls
- 3 pots · button · LED
- I/O
- 1 CV in · PWM audio out
Overview
A clean, general-purpose oscillator with six waveforms — sine, triangle, square, saw, and two FM modes. Every hard-edged waveform gets PolyBLEP anti-aliasing plus a one-pole low-pass to tame PWM and alias noise. Pitch tracks 1V/oct on a negative-slope CV, with a compile-time calibration constant for easy front-panel tuning.
Panel & I/O
| Control | Pin | Function |
|---|---|---|
| POT1 | A0 | Waveform (Sine / Tri / Square / Saw / FM-4× / FM-2×) |
| POT2 | A1 | Coarse tune |
| POT3 / CV | A2 | Frequency / V/oct CV |
| BUTTON | GPIO6 | Octave shift (0 / +1 / +2 / +3) |
| OUT | GPIO1 | Out — 10-bit PWM audio (~36.6 kHz) |
Features
- Six waveforms including two FM modes
- PolyBLEP anti-aliasing on every hard edge
- 1V/oct tracking with calibration constant
- Octave-shift button (0 to +3)
- 1024-sample wavetables with linear interpolation
© 2026 Maddie Synths · firmware based on work by Hagiwo · original firmware CC0 1.0 · hardware design by Hagiwo