Empress Effects ZOIA

A completely modular effects pedal — or synthesizer, depending on how you use it. Permits stereo in/out (or two of each in mono) and CV in/out (configurable). The only limitations are imagination and CPU usage.

• Manual
• Instructions for firmware updates
• Module cheat sheet

To imitate the Music Thing Turing Machine, we use a ring of sample and hold modules as our shift register. The output of the last is fed into both the output and an input switch. The switch is controlled by a comparator whose inputs are the write probability (positive) and a triggered random value (negative). When the latter exceeds the former, the ring continues to loop unchanged; otherwise, a new note is inserted into the start of the loop. Thanks to the module's versatile I/O options, the final output can be sent to an oscillator, a MIDI device, or through the control port as CV.

Unlike the Turing Machine, the number of steps is hardcoded into the patch and cannot be adjusted on the fly (yet). The user can adjust the write probability, clock (which can also be taken from outside the module), and quantization options. It's also a good idea to constrain the quantizer's input to keep the output from swinging too wildly.

An alternative idea would be to use a sequencer as the shift register. This arrangement requires a connection to each step of the sequence, but it allows us to dynamically adjust the number of steps (and program an initial sequence).

Physical I/O for audio, MIDI, UI, and CV.

Controls the pedal's bypass state, performance mode, or stomp aux mode based on CV.

Turns grid buttons into a playable keyboard. Each button can be tuned to any note.

Accepts input from an expression pedal or external CV source. The CPort setting must be set according to the input.

Sends 0–5 V on the ring of the control port depending on the input value. CPort must be set to CV mode in the config menu.

These modules generate or modify audio signals. Unlike typical hardware modular, audio modules cannot operate on CV signals (and vice versa).

CV generation and operation modules.

Like a VCA for CV signals.

These modules create CV signals from audio.

Standard guitar-type effects. It should be possible to assemble most, if not all, of these from the above components.