Dual stereo delay with reverb control

Echoa is a stereo dual delay and reverb processor running on the open Alchemy Lab platform. Four delay lines - two per stereo channel - morph from clean digital delay into smeared, textured reverb from first principles: diffusion sweeps a four-stage all-pass network from discrete repeats to a wash, bloom grows short loops into long modulated plate and hall tails, and bipolar damping darkens or brightens the tail.

Delay time runs 1 ms to 16 s with up to four taps per line and feedback up to and past unity. The four lines route in series, parallel, isolated mono, or spectral with a tunable crossover (100 Hz – 8 kHz). Four character engines - digital, BBD, tape, vinyl - add anything from a gentle touch of color to destruction.

Every pot records a looping parameter-lock modulation; 16 preset slots snapshot every parameter, routing choice, CV map, and lock loop. Sync via tap tempo or external 24 PPQN clock.

The hardware is field-programmable: six CV jacks configurable as in or out, front-facing USB-C for MIDI, micro SD, and an open source SDK. Load Spagyros or any other Alchemy Lab firmware on the same module.

Interactive manual

https://hermeticmodular.com/modules/alchemy-lab/echoa