The knob labeled “M” on the device controls the Modulation Type. It blends seamlessly between different kinds of modulation effects. Turn all the way to the left, you get pure Tremolo, then all the way to the right you get pure Phaser. Under the hood we are achieving these blends through either crossfading between different signal paths (like when moving between Tremolo and Chorus) or adjusting the rate of a delay line (like when moving between Chorus and Flanger).

A parallel system of allpass filters, gain control and a delay line offer a wide array of modulation effects when used in the various configurations described above. They are being driven by a unique, 8-step function generator (or sequencer) with smoothing and rate controls. There is also additional reverb, filters and bit reduction for added flare.

With the sequencer, we wanted to provide more control over the modulation effect than a typical pedal, while still prioritizing ease of use and musical expressivity that pedals are known for.

All of the processing is done digitally on a Teensy 4.1 microcontroller, equipped with an Audio Shield providing easy access to 16 bit, 44.1 kHz audio. Programming was done in C++ in the Arduino IDE.

16 potentiometers control the sequencer and each of the effects, and the user interface is displayed using an I2C LCD.