- Product: Derailer
- Publisher: Physical Audio
- Version: 3.2.7
- Formats: AU, VST3, AAX
- Requirements: Windows 11, macOS 10.13 or later (Apple Silicon or Intel Core processor)
- Source: physicalaudio.co.uk/products/derailer/
Derailer is the first plugin in a while that made me play like a luthier, not a preset surfer. Ten minutes in, I’d built a five-bar instrument tied together with crooked, nonlinear springs; soft MIDI gave me bell glass, but a harder touch bent into snarling overtones that felt physical—like metal protesting. It’s the vibe of a vibraphone, waterphone, and broken sculpture welded into one playable thing.
Quick Facts
- Type: Physical-modeling instrument (no samples)
- Core idea: Build a resonator network from 5 metal bars linked by up to 10 nonlinear springs; set bar mass/rigidity/sustain/tone and spring stiffness/decay/nonlinearity; move connection points to reshape resonance.
- Exciters/Drivers: Plucked strings, bowed strings, pitched bars, sawtooth, multi-striker (gesture/arpeggiator styles).
- FX/Utilities: Resonant LP filter, delay, overdrive (built-in).
- Engine: Finite-difference time-domain (FDTD) numerical modeling—everything reacts, nothing loops.
Hands-On — building instruments instead of browsing presets
Resonator networks that actually behave like metal
The “aha” moment is dragging spring connections between bars and hearing the entire spectrum pivot—chime turns to clang, then to breathy drone—because the coupling literally re-routes energy in the model. Bar mass fattens the fundamental; rigidity and tone move the partials; sustain decides how long the playground rings. It’s surgical without feeling academic.
Five ways to strike (or sing) the metal
I spent most time with plucked and bowed string drivers for lyrical, glassy tones, then flipped to multi-striker for kinetic mallet patterns. The pitched bars driver is shortcut city for tuned percussion; sawtooth brings an almost synth-like push that blooms into metallic harmonics when springs are nonlinear.
Performance response you can lean on
Because it’s modeled—not sampled—velocity, aftertouch, and mod-lane moves feel continuous. Ride filter and bow pressure and the instrument answers rather than switching layers. It lets you perform crescendos that sound like a player leaning in, not a crossfade.
Built-in FX: enough to finish a cue
The resonant LP is perfect for taming fizz while keeping the body; delay and drive sit at the sweet spot—spicy enough to print ideas without bouncing out to your plugin chain. If you need cinematic width, multi-out to your verbs; but honestly, a lot of patches are mix-ready.
At-a-Glance
- 5 bars + up to 10 springs → Assemble unique instruments that morph with touch.
- Bar mass/rigidity/sustain/tone → Aim the spectrum instead of EQ-ing later.
- Nonlinear springs → Expressive grit and bloom under higher velocity.
- Pluck/bow/strike drivers → From lyrical glass to kinetic mallet riffs in one patch.
- FDTD modeling → No samples or IRs; continuous response, alive under automation.
- AU/VST3/AAX on macOS/Windows → Drop into modern DAWs with demo mode to test first.
Real-World Checks
- CPU/RAM: Moderate on a 2021 MBP at 128-sample buffer; heavier when you max spring nonlinearity and pile on strikers, but still playable.
- Latency/feel: Snappy; no jitter in clocked striker patterns.
- Routing/export: Straightforward stereo out; I kept verbs/delays external for film cues.
- Compatibility: AU (Logic), VST3 (Live/Bitwig/Cubase) and AAX support; Windows builds available.
- Stability: Rock-solid in testing; sessions reopened identical each time.
Where it shines — and what to watch
Shines at:
- Tuned percussion & hybrid mallets for score and indie electronica
- Haunted bells/waterphones without samples—fantastic for sound design
- Playable drones that move with velocity/pressure instead of LFO clichés
Watch for:
- If you want bread-and-butter marimba/xylophone out of the box, you’ll still do some modeling; Derailer rewards curiosity more than preset hopping.
- Pushing spring nonlinearity into the red can get wild—cool for horror cues, but print stems before over-tweaking.
Quick Answers
Q: Does it use samples?
A: No—Derailer is pure physical modeling; every change is computed in real time.
Q: How many elements can I connect?
A: Up to 5 bars linked by 10 nonlinear springs, with moveable connection points to reshape resonance.
Q: What drivers are available?
A: Plucked strings, bowed strings, pitched bars, sawtooth, and multi-striker exciters.
Bottom Line
Derailer isn’t a “mallet ROMpler.” It’s a little physics lab that makes new, believable metals every time you touch it—and it reacts like an instrument, not a sample set. If you score, design, or just love building playable anomalies that sit between bell, string, and synth, this belongs on your short list.