CoVariant 1.2.3

CoVariant is a collection of audio units designed to transform a DC-coupled audio interface into a MIDI to CV converter. These units take MIDI note and controller data, as well as timing information from the host app, and convert them into control voltages. These control voltages can then be utilized to govern external analog synthesizers, modular systems, sequencers, drum machines, or other CV-controlled analog equipment.

The app comprises five distinct audio units that can be integrated into AU host apps. It's essential to note that these audio units are not standalone; they necessitate a compatible host for operation.

CoVariantAU serves as a MIDI to CV converter that furnishes outputs for CV/Gate, two MIDI controllers, and two ADSR-type envelope generators. It encompasses features such as last, low, and high note priorities, multiple or single trigger modes, legato or continuous glide/portamento with constant rate or constant time modes, and pitch bend capabilities. The controller outputs offer customization options including note velocity, aftertouch, or any MIDI continuous controller number from 0 to 127. Furthermore, the controller outputs are engineered to deliver smooth transitions to avoid abrupt changes.

TriggerAU acts as a simplified variation of CoVariant AU tailored to respond to MIDI note events. It provides outputs for gate/trigger and one MIDI controller, primarily serving the purpose of controlling drum modules or converting MIDI controller data into control voltages.

ClockAU generates outputs for Clock and Run/Stop/Reset functions, enabling synchronization of analog sequencers and DIN Sync drum machines or synthesizers/sequencers with the tempo and transport controls of the host app.

PolyphonyAU is a MIDI processor that operates as a polyphonic voice controller, supporting multiple instances of CoVariantAU simultaneously.

EncoderAU facilitates the utilization of Expert Sleepers ES-5, ES-40, ESX-8GT, and ESX-8CV eurorack modules. It allows routing of outputs from other AUs (or any software functioning as a CV/Gate source) to the hardware outputs of the ES/ESX modules.

These Audio Units necessitate a host application that backs multi-channel audio interfaces. Notably, GarageBand lacks this capability and hence is incompatible. The precision of ClockAU hinges on the timing and transport state data provided by the host app. EncoderAU mandates a host app capable of supporting an AU with multiple input busses (AUM by Kymatica comprehensively supports this AU).