Using the tilt of an iPad to control an analog feedback-based patch.
In this patch, I send OSC (Open Sound Control) data about the tilt of my iPad to Max/MSP on my computer, which converts this data into MIDI, and subsequently, on my synth, voltage. That voltage (changing based on the iPad’s tilt) opens up a VCA (voltage-controlled amplifier) which controls the level of the feedback.
The analog feedback loop here goes: ring-modulator to saturator to reverb to delay to low-pass filter to the VCA (which runs back into the ring-modulator).
Here’s a simple patch based off the work of composer/engineer Jaap Vink from the Institute For Sonology, Utrecht. This ensemble is a feedback loop with a delay, a ring modulator, and a saturator (with a simple sine as a “trigger” to get things started).
Each pass through the loop, the signal is delayed, then ring-modulated, significantly changing the spectrum. This can devolve into noise rather quickly, but a soft touch can lead to some interesting evolving soundscapes.
There’s no talking on this one, just building the patch, and listening to it go.