Arna is a free reverb plugin for macOS — VST3 and Audio Unit, native on Apple Silicon and Intel. Built on a Differentiable Geometric Feedback Delay Network with brain-driven spectral analysis. The free 1snob edition gives you one knob — turn it and the room grows from a tight, dry corner all the way to an infinite ember. Automate it and you get tape-like, breathing textures by design.
This is the real Arna engine running in your browser, not a recording. Pick a dry take, turn the journey knob, try the nine Full knobs, then hit Freeze and play the frozen space with your keyboard.
Headphones recommended. Nothing you play or upload leaves your computer. Open the demo on its own page →
Most reverbs sit on the bus and apply the same impulse no matter what you feed them. They don't listen. They don't adjust. The result is a room that doesn't belong to the music.
Arna's brain listens to what you feed it — peaks, valleys, transients, sustained content — and shapes the tail with intent. The Journey lives inside one knob: as you turn it, size, decay, tone, and diffusion move together along five honest phases. No menu diving. No cargo-cult. The same knob, automated, becomes the texture itself.
The free editionships with a single knob and a single mix fader — that's the entire UI. The Full edition opens up the same engine across nine knobs, A/B compare, presets, and a Freeze you can play — hold the reverb, then perform it from the keyboard. Same DSP source. Same craft.
The k value of the 1snob knob traverses a thermometer of five anchor colours, and the sound follows. Behind the knob, the plugin paints the journey live — Brain pulse modulates the bloom intensity at audio rate. You hear what you see.
Neutral, dry, controlled. The room is barely there.
Natural, defined. A real space, modest in size.
Musical bloom. The tail starts to sing.
The plugin's own voice. Not a room — a presence.
Deep ember, infinite. Ambient territory.
The DSP engine in dsp/ is identical across all three. Only the wrapper layer changes. The 1snob edition is free for personal and commercial music production — no nag screen, no watermark, no time limit.
One knob, one fader and Freeze. The single knob drives the full reverb engine — size, decay, tone, and diffusion all move together along the Journey. No menus, no presets.
Nine knobs, A/B compare, presets, and a playable Freeze. Same engine — full hands-on control over predelay, reflections, tail, size, bloom, texture, width, tone, and mix. Freeze isn't just an infinite tail; hold the room, then play it like an instrument.
The calibration rig: 10-tab panel, 100+ faders, 13 visualizers. The instrument used to tune the engine itself — and the source of the reference renders you hear on this page.
Every knob renders identically: cream body, copper indicator, no per-knob accent fill. You find a knob by label and position, never by hue. Predictable in low-light or on-stage contexts.
Row 1 — five small knobs (radius 24 px) for time-domain shaping.
Row 2 — four large knobs (radius 34 px) for character and balance.
Distance before the room answers.
Level of first reflections.
Level of the late tail.
Size of the space, from under 1 s to about 8 s.
Late reverb swell.
Algorithmic character of the diffusion.
Stereo image, 0–200%.
High-frequency damping.
Dry / wet balance.
Toggle between the dry source (A) and Arna's rendered tail (B) at any point during playback. Position carries across, so you hear the exact same instant of the take with and without the room.
How to A/B: hit play, then click Dry or Wet to switch sides without losing your spot. Use the scrubber to skip to the part you care about. One pair plays at a time — starting another pair stops the first.
Headphones recommended. Sources: /media dry stems, mp3 96 kbps. Wet rendered through a reference Arna preset matched to each material.
Solo piano figure. Hear the room open up around the attack.
Acoustic kit. Snare and toms gain depth without losing the hit.
Short bow strokes. Watch the tail blur the seams between notes.
Sustained vocal line. Crown phase: the voice grows its own halo.
Validated through pluginval Level 10, a custom torture battery, and ctest before any release. The engine never allocates on the audio thread.
Yes. Free for personal and commercial music production, with no time limit, no watermark, and no nag screen. The Full edition is paid (not yet available) and uses the same engine.
Not at launch. Arna is built on JUCE 8 and the engine is portable, but our validation gate runs on macOS only. A Windows build is on the wishlist after Full ships.
Two colours that survive bad monitors, on-stage lights, and screenshots. Cream as the universal "lit" signal, orange as the field. The two cold colours in the system — iceBlue for Freeze, coral for destructive actions — are earned, not decorative.
Differentiable Geometric Feedback Delay Network. A reverb topology where the routing is geometric (rooms model real spatial behaviour) and the parameters are differentiable, so we can train them end-to-end against target impulse responses.
Yes — the 1snob edition is free for personal and commercial music production. No additional licence required. Credit appreciated, never demanded.
Download the free edition and find the room. Get on the list to be first when Full ships.