Fragua
The name says it plainly. Fragua is Spanish for forge
the place where raw material is heated and hammered into form. That's the verb the whole instrument is built around: you take the raw output of a chaotic engine and forge it — through envelopes, filters, deep modulation and a full mastering chain — into a finished sound.
Fragua is not a subtractive synth wearing a new coat
At its heart sit nine sound engines built on chaotic and strange-attractor systems: swarming oscillators, double-well resonators, reaction-diffusion fields, morphing wavetables woven into grain clouds. Feed them a note and they don't produce a static waveform — they evolve one. Two notes are never quite identical. And yet nothing is random: the chaos is deterministic, so what you build is repeatable, musical and yours.
Our Main
Features
Three stackable engines per note
Every key can sound up to three engines at once, each with its own complete voice chain — oscillator, sub-oscillators, envelope, filter, EQ, output. Layer a tonal engine under a chaotic one; let one lane sustain while another fires and fades.
Nine engines, nine flavours of chaos
From swarming particle clouds to a 2-D morphing wavetable woven into grains. Each engine is a different chaotic system — no two behave alike, and none of them ever quite repeat.
Deep, audio-rate modulation
Eight LFOs, four drawable vector envelopes, four attractor modulators and a full modulation matrix with macros, MIDI/MPE and per-note keytracking. Almost anything can modulate almost anything — including other modulators.
A mastering studio, built in
A 5-band EQ on every engine, plus a master chain with EQ, saturator, compressor, stereo width, limiter and true-peak metering — and three serial FX buses. Patches arrive finished.
Built to be seen
Live scopes on every lane, a 3-D spectrum on the master, modulation drawn right onto the faders, and detachable editor windows you can float onto a second screen.
Deterministic, not random
The chaos is alive but repeatable. Save a patch and it comes back exactly as you left it — motion and all.
The Nine
Engines
Nine engines. Each one a different kind of chaos — and none of them ever quite repeat.
Enjambre (swarm)
A swarm of oscillators that pull on each other's phase until they scatter into shimmering partials or lock into one glassy tone.
Pozo (well)
A double-well oscillator that sits calm, then leaps chaotically between two states: tonal and resonant one moment, gnarly the next.
Hilo (thread)
A three-dimensional chaotic flow weaving smooth, sinuous, ever-moving orbits — organic at rest, turbulent when pushed.
Confluencia (confluence)
Two strange attractors, Lorenz and Rössler, running side by side and mixed where their currents meet.
Arena (sand)
Fractal chaos maps iterated sample by sample: granular, grainy, impulsive sound you can play like an instrument.
Arco (arc / bow)
The classic Chua chaotic circuit, bifurcating wildly into crunchy basses, restless pads and incisive leads.
Mitosis (cell division)
A reaction-diffusion field where two forces feed and kill each other, forming and splitting patterns like dividing cells.
Crisol (crucible)
Thirty-two sine partials melted and stirred by a slow Lorenz attractor into an ever-shifting spectrum.
Telar (loom)
The deepest engine: a 2-D morphing wavetable woven into a granular cloud and rewritten in real time by its own chaos.
Who We Are
Pura Belia
Sound, without limits.
Pura Belia is a project dedicated to the creation of innovative sound tools. Born from real experience in production and modular synthesis, its mission is to develop powerful, open, and inspiring instruments to explore sound without limits.
Founded by Ribé, a DJ and producer with a solid trajectory in the international scene, Pura Belia emerges after years of work in modular synthesis, production, and performance — an environment where sound is not used, but built. Throughout his career, Ribé has developed a distinct sonic language, exploring open systems and limitless approaches to creation, beyond genres or traditional structures.
This vision has led him to be part of key labels such as Kockworks and PoleGroup, alongside artists like Ben Klock and Oscar Mulero.
Pura Belia is the materialization of that vision.