PA3 Derailer

PA3 Derailer




Free Download Buy Licence

Modular physical modelling

Derailer is a physical modelling system with two basic elements. One is a metal bar that you can strike or bow. The other is a nonlinear spring connection. This allows you to join two bars together so that vibrations from one create sympathetic resonance in the other. By connecting multiple bars you can create new instruments that have their own unique sound. Derailer uses finite-difference time-domain numerical modelling.



Tuned bars and resonators

The bars are arranged into 37 tuned bars, grouped into half-octaves, and 5 resonators. Springs can be added to connect the tuned bars to the resonators, and to connect resonators to each other. A further set of springs can be used to connect each tuned bar to its neighbour. The graphical view allows the connections to be moved around, and for elements to be selected so their parameters can be changed. There are two ways to play the instrument. The tuned bars can be struck with a mallet, giving a playable range of 3 octaves and unlimited polyphony. There is also a bowing mechanism that is applied directly to the first resonator. This has a range of 5 octaves and 4 note polyphony.

Sound design with real acoustic qualities

Derailer comes with over 60 factory presets, covering instruments such as vibraphones, cymbals, gongs, drums and bowed instruments. This gives a range of sounds such as rhythmic percussion, melodic leads, and textured pads which are ideal for sound design. The randomize button allows you to easily create new instruments, whilst Edit mode gives you fine control over the parameters for each element of the system.



Dynamic Expression

One of the key benefits of physical modelling is the level of expressive control that is available. With bowing we can vary the attack time, bow pressure, vibrato and pitch bend, as well as LFO rate and depth. Striking has variable force and position, and the bar mass and connection strengths can be changed in real-time. There is also a flexible multi-striking system, whereby held notes can create dynamic rhythmic patterns using MIDI to vary the individual strikes. See the plug-in's Help screen for the full list of MIDI controls.

Parameter Space

Derailer has two types of parameters. There are the real-time continuous controls as detailed above, whilst the remaining parameters are 'state-reset' types. These parameters make fundamental changes to the physical model, and react to mouse-up on the interface where they trigger a fast reset in preparation for the next Note-On. For bars, the sustain, tone, boundary supports and stiffness (for the resonators) are state-reset controls. For the springs, the connection position and degree of nonlinearity are state-reset.



Presets Demo





Demo track by Makunouchi Bento


Derailer + ROLI Seaboard

In Xmode, Derailer can be controlled by MPE devices such as the ROLI Seaboard.
This allows individual control of pitch when bowing, and strike force when multi-striking.


Free to use in Demo mode


PA3 is free to download and use in Demo mode.
The only restrictions are the output is cut for several seconds each minute, and saving new Presets is disabled.
See the downloads page for the latest version and system requirements.