Someone finally built a whole instrument around a phase-locked loop, and my first thought was: of course. A PLL is a radio control circuit whose whole job is to grab onto a signal and not let go. Phaseburn took that loop, put a UI on it, and said the best sounds live exactly where the loop starts to fail.
The voice architecture is wild on paper. The oscillator is a vector phase-shaping unit with an FM section and a 12-mode morphing core plus a sub, and the PLL sits underneath with exposed loop coefficients and four big macro dials called Grip, Fight, Color, and Width. Tune those by ear and you are basically steering how hard the loop holds on. Push it and you get lock, slip, overshoot, jitter. In industrial terms, that means basses that sound like they are fighting the power grid, and lead lines with a built-in sense of menace that no amount of saturation can fake.
Then there is the PLL LAB lock map, which is my favorite page of the whole thing. You drag around on a map of where the loop locks, slips, or goes chaotic, and play it like an instrument. Overshoot and jitter stop being bugs and become the whole performance. For horror-adjacent sound design this is exactly the kind of playability I keep asking for.
The sequencer is a probability machine rather than a step grid. Instead of on/off steps it rolls dice between note lengths, works from a scale-aware note pool, and has a strength map plus beat links with fills and ratchets. It never repeats itself, and every note it rolls leaves the plugin as MIDI, so you can drive whatever other instrument you want with it. Imagining a ten minute roll feeding a distorted drum bus still hasn't gotten old, and I haven't even loaded it yet.
The effects rack is no afterthought either. Two multimode filters, a frequency-shifting delay, FDN reverb, chorus, distortion, bitcrusher, a granular freezer, and a three-band parametric master EQ with a true-peak limiter, all wired through a modular patchbay with feedback taps. You can repatch while it plays. And there is a stereo audio input with sidechain, so you can drop Phaseburn One on a track as an insert effect and let the PLL lock to external audio. That alone justifies keeping it in the template.
Specs for the nerds: the DSP is written in Rust, 64-bit core, oversampled, zero-delay filters, with the published research credited on the site. Four cross-modulating LFOs with a drawable editor, four mod sequencers, over 240 modulation targets. 256 factory presets across eight banks, plus eight user banks the same size, with JSON import and export. VST3, CLAP, and AU on Mac (universal binary), VST3 and standalone on Windows. Perpetual DRM-free license, free updates across 1.x, activates on up to three machines. This is v1.0 after a public beta that ran since August, so it is not day-one code.
Honest notes: the free demo is the full synth, but the audio dips briefly every couple of minutes and it puts a soft noise watermark on your bounces. Registering lifts both. The price is €149 with no intro discount, which stings a little for day one, but two-person teams writing their own DSP in Rust do not owe anyone a sale.
Price: €149 incl. VAT, one-time perpetual license, free updates across 1.x, free demo available.
Phaseburn One on phaseburn.music - company site: phaseburn.music