by rumcake
Ferro
A macOS techno instrument built on a real ferrofluid.
The magnetic pulse plays the super saw.
One-time purchase. License key delivered instantly by email.
No subscription.
The product
Magnetism writes the riff.
Ferro simulates the Rosensweig instability: a pool of magnetic fluid that erupts into a lattice of glossy spikes when a field crosses critical. The field pulses on your grid, spikes erupt on the beat, and their tips write a riff that LOOPS: one, two or four bars, locked tight to the 16th grid. Hold a chord and the riff arpeggiates it; change the chord and the riff follows. A vary control sets how often the fluid rewrites a step, from hypnotic lock to free-running storm.
The fluid writes the loop
A Swift-Hohenberg surface on a 64x64 grid grows the hexagonal spike lattice of a real ferrofluid, volume conserved. Erupting spike tips are quantised onto a swung 16th-note grid and recorded into a looping riff with a bass anchor on the downbeat. Vary at zero locks the loop; turn it up and the physics keeps mutating the line.
Chords in, melody out
The riff plays the chord you hold, spread over one to three octaves, and follows your changes: same rhythm, new pitches. The keyboard also plays the super saw directly, scale-snapped with real sustain, so you can pad the chord and solo over your own groove. Latch keeps it rolling after you let go.
Super saw
Seven detuned saws on a classic super-saw curve, plus a sub, through a resonant filter the spike height sweeps open. Drive for grit, an ensemble widener, a dotted-eighth ping-pong echo, and reverb. Dark rolling pluck at one end, screaming acid at the other.
It plays your rig back
Lock the groove to your host with swing and any division from 1/4 to 1/32. Every step can emit MIDI out, so Ferro sequences your other gear. Poke the fluid by mouse, or play it from the keyboard.
Hear it
Nine grooves, from rolling techno to acid.
Each demo holds a chord progression (Am, F, C, G) and lets the ferrofluid write and loop the riff around it. Click a card to hear the wiring.
Want to try it on your own material? Download and install the plugin, it runs as a fully functional free trial, with a short noise wash over the output every 30 seconds until you activate it with a license key.
Buy
Ferro
£25
One-time purchase. Free updates to this version. License key by email.
One-time purchase. License key delivered instantly by email.
No subscription.
Or download the free trial first
No refunds on serialised software. By purchasing you agree to the terms of service. Contact contact@rumcakerecords.com for support.
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Or get every physics plugin in one purchase: The rumcake rack — £89.