Tetrad

Immersive, sculptural sound design

Tetrad is a hybrid instrument based on physical modelling and granular synthesis. A unique quad bus signal chain feeds 4 modelled plates alongside a full modulation matrix. Tetrad was developed in collaboration with composer and transmedia artist Gadi Sassoon. The instrument takes four oscillators, routes them in combination through a Quad AM processor, a specifically tailored Granulator, and four physically modelled plate resonators. Inspired by Gadi’s sculpture-based synth installation, Tetrad was originally devised as a complement to the slashed plates and sound generators of the experimental setup, but has grown into an instrument that puts the capabilities of the installation into a single piece of software in a DAW.

Features

• Quad oscillator unit with Frequency Modulation. Oscillators can be tuned in  various ways according to the chosen mode, from basic intervals to diatonic inversions.
• Sidechain Audio option, bypassing the oscillators and allowing any signal to be used.
• A 4×4 Matrix Mixer blends the four inputs onto four busses.
• Quad Amplitude Modulation with Depth, Shape and Rate, which works well into the audio range, and Phase set individually per bus. 
• Quad Granulator, where the signal is split into grains that are replayed in different ways. You can affect the grains’ window shape, Size, Pitch, and change the Feedback of the granulator.
• 4 physically-modelled plates with preamp drive and sound stage design.
• 3 individual filter sections with choice of Lowpass, Band, or High pass filters.
• Modulation matrix with eight LFOs, MIDI values and MPE dimensions. Envelopes include the synth’s main ADSR as well as some envelope-following signals, which are derived from the AM and Granulator levels.
• MPE support. Velocity, Slide, Pressure and Glide are available as modulation sources for the full MPE experience. In MPE mode, pitchbend and glide are available continuously across the full range of MIDI notes.
• MTS-ESP micro tuning support.