[Photos by Glenna Jennings]
Dub Machines- Rails
This device is an updated version of the Linear Actuator, a manual rhythm controller. This device consists of a handle with 8 momentary pushbuttons that slides between two hard stop limits. A linear encoder is attached to the slide mechanism reading back the position with very high resolution. The hard stop limits are adjustable via handwheel and lead screw with dovetail, allowing a 4 inch to 25 inch travel. This device is highly reconfigurable given the position, velocity and 8 buttons as input data. Currently, the Rails device is setup to trigger at each end of the travel with velocity sensitivity based on slide velocity. The trigger only occurs at the limits if a button or combination of buttons is pressed when crossing the limit, otherwise no trigger occurs. The entire periodic motion also acts as its own general expression controller and can be switched on and off through software, an example of another function of the device.
Overall, the Rails device is intended to be the “sequencer” or metronome of the performance but lacking a machine-like precision or click. Instead the user can continuously move between the limits in his/her own rhythmic or arrhythmic manner changing sounds at each point and fluctuating in a more human and emotional manner. Performances with the Dub/Drone Machines are intended to follow the players mood in a somewhat unintentional improvisation in a way that a BPM’d sequence cannot.
2 ports on the back (3 total with the USB) provide sustain and channel switching but are completely reprogrammable to allow them to be any type of switch or expression control.
The brain of the Rails is the Arduino Duemilanove. Currently the device is programmed to output USB/MIDI to Ableton Live, but can easily be configured to output OSC commands to communicate with Pd, MAX, Reaktor, etc.
