Sound design often feels like stepping into familiar territory. You load up a synthesizer, pick a sawtooth or square wave, tweak a filter, and dial in an envelope. While this subtractive approach has powered decades of incredible music, the architecture of modern DAWs rarely pushes us to think completely outside the box.
At OMNi, we didn't just want to build another standard subtractive synth. We wanted to create a sound generation engine that forces you to approach synthesis from an entirely alien perspective, yielding organic, unpredictable, and physically grounded textures.
So, we threw out the standard oscillator list and replaced it with the Periodic Table of Elements.
Meet Alchemy—our brand-new polyphonic synthesizer where you don't tweak oscillators; you mix chemical compounds.
Here is a deep dive into how it works, why it's not just a visual gimmick, and how Rust's architecture made it possible.
From Chemistry to Sound: The DSP Translation
In Alchemy, you start by loading elements into a "reactor". There are 118 elements available, and each one possesses real, hardcoded physical properties: atomic weight, valence, ionisation energy, electronegativity, and group membership.
But how does chemistry translate into audio? In OMNi, our bake_patch() engine acts as a mathematical translator, mapping these physical constants directly to our DSP matrix:
- Waveform Selection via Element Groups: The core oscillator structure is determined by the element's family. Alkali metals generate morphing wavetables, transition metals trigger complex FM (ChaosFM) algorithms, halogens produce vocal "Vowel" formats, and chalcogens utilize a unique SinFold algorithm.
- Filter Cutoff via Electronegativity: The direction and aggression of the synth's Zero-Delay Feedback (ZDF) filter are driven by the element's electronegativity (using the Mulliken proxy). Electronegative nonmetals raise the cutoff for sharp, aggressive bites, while electropositive metals invert the envelope for deep, resonant plunges.
- Modulation via Atomic Weight & Ionisation: The atomic weight maps directly to FM operator ratios, while ionisation energy controls the ADSR envelope's release times and modulation indices. Heavy, highly ionised patches sound physically massive and volatile.
When you blend elements using our Stoichiometry drag control, you aren't just crossfading audio; you are mathematically interpolating their chemical properties in real-time, resulting in entirely new sonic alloys.
The Engineering Behind the Magic
Mapping physical constants to DSP variables is an amazing concept, but executing it flawlessly in real-time is an immense technical challenge. This is where OMNi's Rust-based architecture shines.
1. Wait-Free "Hot-Swaps"
When you change an element or adjust the chemical mix, you are radically altering the core architecture of the synthesizer's patch. In traditional languages, swapping such a complex data structure on the fly could cause a lock or a memory allocation, resulting in a dropped audio frame (a click or pop).
In OMNi, we utilize Rust's atomic pointers (Arc<ArcSwap<ReactorPatch>>). This allows the UI thread to prepare the new chemical compound in the background and swap it into the audio thread instantly. The audio thread never waits, never locks, and never clicks—even when radically altering the chemical makeup of a playing chord.
2. Zero Allocations & SIMD Processing
Alchemy is a beast of a synth: it features a 16-voice polyphony system driven by a Braids-style carrier, a 4-operator Phase Modulation matrix, an ADAA wavefolder, an SVF filter with pristine f64 coefficients, and an 8-line FDN reverb.
Because OMNi's audio callback strictly forbids memory allocation, every single voice, delay line, and modulation matrix is pre-allocated before you even press a key. Rust's strict memory safety ensures that this massive, interconnected chemical reactor runs with absolute deterministic performance.
3. Modulating the Unpredictable
To breathe life into the static chemistry, we integrated the Marbles modulator—a stochastic, Turing-machine-style LFO that provides organic jitter, spread, and bias. When you route this modulator to the reactor's "Timbre" or "Color" parameters, the synth begins to react like an unstable isotope, bubbling and shifting with incredible organic realism.
A New Paradigm in Sound Design
Alchemy proves what is possible when you build a DAW architecture from the ground up to be fearless. We didn't have to compromise the mathematical purity of the synthesis to make it run smoothly. By leveraging Rust, we built a synthesizer that calculates the chemical properties of Plutonium and Oxygen to generate a wavefolder bassline, all without dropping a single sample.
Alchemy is available now, exclusively in OMNi. It's time to put on your lab coat.