Maddie Synths
Open-source DIY Eurorack modules I have built and sell.
These are my open-source Eurorack experiments — mostly small, cheap boards where the firmware defines the module. Each card below is a single firmware build / module. This is inspired by things like the WGD Modular melon.
The MOD1 and MOD2 hardware is an open designs by Hagiwo — see the original build guides for MOD1 and MOD2. All firmware lives in the maddie-synths repository.
Maddie MOD1
Butterfly
Chaos · Modulation
A Lorenz-attractor chaos source for organic, non-repeating CV — chaotic, but never random.
Dual Env
Envelope
Two independent attack-decay envelopes with per-trigger random timing variation.
Envelope
Envelope
A three-output envelope generator with a self-patchable end-of-cycle out for LFO or clock duty.
Euclidean
Sequencer · Trigger
8- or 16-step Euclidean rhythm generator with adjustable hits and per-step probability.
LFO
LFO · Modulation
A simple but CV-rich LFO — modulate frequency, waveform, and level for chaotic motion.
Logic Pair
Logic · Utility
A dual logic processor: AND/NAND, OR/NOR, XOR/XNOR, COMPARE, MAX/MIN, and FLIP-FLOP.
Random CV
Random · Sequencer
A looping random CV and trigger sequencer with selectable length and trigger probability.
Random Walk + Lag
Random · Modulation
An ultra-slow random walk with a lagged second output for ambient, crossfading textures.
Tap Tempo
Clock
A four-output tap-tempo master clock with multiplied and divided outputs.
Terrain LFO
LFO · Wavetable
A procedurally generated triple-wavetable LFO with probabilistic SloMo 'breaths'.
Trigger Burst
Trigger · Clock
Clock-syncable trigger bursts with selectable count, division, and an internal clock.
Maddie MOD2
808 Clap
Drums · Percussion
A TR-808-style digital hand-clap: gated noise bursts into a band-passed exponential tail.
Acid 303
Bass · Sequencer
An 'acid' 303-ish bass voice with a built-in Turing-style generative sequencer.
Breakbeats
Sampler · Drums
A PCM break-beat player with CV-selectable slice points, variable speed, length, and loop mode.
Claves
Percussion · Voice
A tunable claves/woodblock voice with morphable sine↔triangle waveform and 1V/oct tracking.
Flux
Noise · Physical Modeling
Seven modes from tuned resonance to pure chaos — modal, Karplus, noise colors, Lorenz, and drone.
FM Drum
Drums · FM
A two-operator FM percussion voice — six parameters across two modes with smooth pickup switching.
HiHat
Drums · Percussion
A white/blue-noise hi-hat with adjustable decay, decay curve, and band-pass frequency.
Kick Drum
Drums · Percussion
A sine-based kick drum with six parameters and soft-clip drive, switchable via the button.
Radio
Sampler
A long-form sampler for vocals and speech — up to ~130s with variable speed and direction.
Sample
Sampler · Drums
A one-shot PCM sample player — up to 18 samples in flash, selected via two-stage CV.
Spirals
Oscillator · Experimental
Auditory illusions and impossible sounds — Shepard tones, Risset rhythms, and tritone paradoxes.
Square VCO
Oscillator
A V/oct square-wave oscillator with vibrato LFO and chiptune-style octave toggling.
Tiny Braids
Oscillator · Macro-oscillator
A Mutable Instruments Braids macro-oscillator port — dozens of synthesis models in 4 HP.
Tiny Tides
Oscillator · Function Generator
A Mutable Instruments Tides port — a tidal wavetable generator and function source in one.
VCO
Oscillator
A six-waveform oscillator with PolyBLEP anti-aliasing and negative-slope 1V/oct CV.
Blank Panels
Blanks in every width I actually needed, drawn to the same house style as the module faceplates — 128.5 mm tall, brand text at both ends so it reads upright either way up. Front and back carry different artwork, so one board is really two panels: mount whichever face you want showing. You can buy them from my Etsy shop.
Front
Back
