# RELAY — two-slot effects processor

Chain two effects. Shape one sound.

RELAY processes an incoming track or instrument through two effects in order:
**audio input → slot 1 → slot 2 → audio output**. Each slot can use any of ten
effects, including two copies of the same effect. Start with a filter followed
by reverb, or put a rhythmic chop before a rough digital texture.

## What you need

Daisy Seed on a Daisy Pod, Amen Bootloader, an audio source and the Pod's audio
output connected to your listening setup. No screen is required. This release
uses the Pod's knobs, buttons and LEDs; it does not include a web editor.
USB is for installing the firmware, not audio streaming.

## Controls

- Click and release the encoder to choose which slot you are editing.
- Turn the encoder to change that slot's effect immediately.
- The two knobs adjust the selected effect. They use their current physical
  positions when focus changes, so settings can jump when you switch slots.
- Hold the encoder and tap Button 1 to bypass or enable slot 1.
- Hold the encoder and tap Button 2 to bypass or enable slot 2.
- A bright LED indicates the slot you are editing; the other active slot is dim.
  A bypassed slot has its LED off.
- With the encoder released, the buttons perform the selected effect's actions
  listed below.

## The ten effects, in encoder order

| Effect | Knob 1 | Knob 2 | Buttons |
| --- | --- | --- | --- |
| Bi-Filter Sweep | Darker to open to thinner | Resonance | — |
| Infinite Wash | Reverb tail length | Original/reverb blend | Button 1 toggles feeding new audio into the reverb |
| Transient Gater | Gate threshold | Closing fade: short to long (20–500 ms) | — |
| Euclidean Tremolo | Rhythmic chop speed | Number of pulses | — |
| Spectral Isolator | Bass level | Treble level | Hold Button 1 to remove bass; Button 2 to remove treble |
| Formant Filter | Vowel character | Movement speed | — |
| Bit Crusher | Digital roughness | — | — |
| Sample Rate Reducer | Grainy digital texture | — | — |
| Dual Mono Maker | Left/right position of a mono mix | — | — |
| Gain Stager | Output level | — | — |

Some effects change the stereo image: Formant Filter uses the left input and
sends its result to both outputs; Dual Mono Maker combines the inputs before
panning. Infinite Wash's hold stops new audio entering the reverb, but its tail
still decays. MIDI tempo sync is not offered in this release.

## First listening check

Start at a low listening level, with Knob 1 around the middle and Knob 2 low.
The starting chain is Bi-Filter Sweep → Infinite Wash. Turn Knob 1 to hear the
filter. Click and release the encoder: LED 2 becomes brighter. Turn Knob 2 to
bring in reverb. Bypass each slot with encoder + its button, then bypass both
to compare with the original input. Cycle through each slot's ten effects.

## Release notes

Experimental QSPI build, 12 October 2026, from `pod/DJFX_Suite`.
Requires Amen Bootloader and preserves it during installation. One firmware
runs at a time; installing RELAY replaces the current QSPI application.

This build fixes encoder focus switching, removes the repeated 50-position
selection list (there are ten distinct effects), starts with the intended
filter/reverb pairing, and keeps effect initialization out of selection-time
audio processing. Re-selecting an effect preserves its internal state.

Built from the local working tree. Host tests cover serial order, independent
bypass, focus switching, the bypass modifier and selection wrap. The full image was flashed to a Seed and read back byte-for-byte. An on-device
listening check is pending. Switching effects is immediate; click-free changes
and every effect combination have not been verified.


## Gate crackle fix — 12 October 2026

Fixed a detector coefficient that made the gate close between waveform peaks,
plus an excessively fast output fade. The gate now uses a stereo-linked peak
detector, a short hold and a smooth closing fade. Knob 2 turns clockwise from
a short to a long fade (20–500 ms time constant).

Automated signal checks cover steady tones from 30 Hz to 4 kHz, quiet-signal
rejection, right-channel-only input, release range and matching timing at 48 and
96 kHz. The replacement binary builds successfully. Its on-device listening
check is still pending; the flash verification above refers to the prior build.