999 Dub Warning
A small, immediate dub warning siren for the Workshop Computer. Main sets the base pitch, X drives the sweep, CV In 2 colors the oscillator, and Y opens up the PT2399-style delay. Use Z Down for a compact Wheel Up one-shot gesture, Pulse In 1 for a gated siren, or Pulse In 2 for reset plucks and fast-trigger textures. Audio In 2 can override the Main pitch knob when patched.
Panel
PitchSweepEffectPitch ModMain CVPitch CVColor CVFireReset PluckWarning MixDirect + EchoLFOEnvelopeActive GateHitControls
Pitch
Base siren pitch, defeated by Audio In 2 when patched
Sweep
Sweep rate and pitch bend depth
Effect
Raises delay time, modulation, repeats, dirt, and wet level
Continuous: Free-running siren
Gated: Triggered siren that fades after Pulse In 1
Wheel Up / Reset: Move Down to fire the Wheel Up one-shot and reset phase
Inputs & Outputs
Inputs
Outputs
Inputs
Pitch Mod
Audio-rate or CV pitch modulation mixed with CV In 1
Main CV
Overrides the Main pitch knob when patched
Pitch CV
Adds to the base siren pitch
Color CV
Modulates siren wave color and drive
Fire
Rising edge fires the normal gated siren envelope
Reset Pluck
Rising edge resets oscillator/LFO phase and fires a short pluck; fast triggers create useful textures
Outputs
Warning Mix
Main warning siren output through the wet/dry effect mix
Direct + Echo
Alternate direct-plus-echo output
LFO
Internal siren sweep LFO
Envelope
Gate and hit envelope for patching other modules
Active Gate
High while the siren envelope or Wheel Up gesture is active
Hit
Short pulse on trigger, reset, or Wheel Up
LEDs
Gate
Brightness follows siren level
Pitch
Shows active Main pitch source, either the Main knob or Audio In 2
Sweep
Shows X knob position
Effect
Shows Y knob position
LFO
Follows the internal sweep LFO
Hit / Echo
Flashes on trigger, then follows echo return level
README
Dub Warning
Beta status: passed single-device hardware testing.
Dub Warning is a playable siren oscillator for the Music Thing Modular Workshop Computer. It makes a bright triangle-to-square tone, bends it with an internal LFO, adds a short noisy attack on triggers, and feeds it into a PT2399-style delay that can smear into a reverb-like dub wash at high repeat settings. Z Down fires a compact Wheel Up one-shot gesture for punctuation before drops, while Pulse In 1 fires the normal gated siren. Pulse In 2 is a reset pluck: at fast or audio-rate triggers it becomes a useful rhythmic/noisy exciter, especially while sweeping Main pitch.
The card is meant to be immediate: patch either audio output, grab the knobs, and hit the switch or a pulse input when you want the siren to shout.
Controls
| Control | Function |
|---|---|
| Main | Base pitch, unless Audio In 2 is patched |
| X | Siren sweep rate and pitch bend depth |
| Y | PT2399-style delay character: time, modulation, repeats, dirt, and wet level |
| Z Up | Continuous siren |
| Z Middle | Gated mode. Pulse In 1 fires the siren, then it fades away |
| Z Down | Fire Wheel Up one-shot and reset phase |
Inputs
| Input | Function |
|---|---|
| Audio In 1 | Extra pitch modulation |
| Audio In 2 | Main pitch CV override. When patched, it defeats the Main knob |
| CV In 1 | Extra pitch modulation |
| CV In 2 | Siren color and drive modulation |
| Pulse In 1 | Fire gated siren |
| Pulse In 2 | Reset oscillator/LFO phase and create a short pluck |
Outputs
| Output | Function |
|---|---|
| Audio Out 1 | Main siren through the wet/dry effect mix |
| Audio Out 2 | Alternate direct-plus-echo output |
| CV Out 1 | Internal LFO |
| CV Out 2 | Gate / hit envelope |
| Pulse Out 1 | Gate while the siren or Wheel Up gesture is active |
| Pulse Out 2 | Short hit pulse on trigger/reset/Wheel Up |
LEDs
| LED | Meaning |
|---|---|
| LED0 | Siren level / active gate |
| LED1 | Active Main pitch source: Main knob or Audio In 2 override |
| LED2 | X sweep knob position |
| LED3 | Y delay/effect knob position |
| LED4 | Internal siren LFO |
| LED5 | Wheel Up / hit envelope while active, otherwise echo return level |
Test
Use UF2/DubWarning.uf2 for hardware testing. The full input
and output test checklist is in TEST_PROCESS.md.
Development notes
The firmware uses the ComputerCard framework and keeps the audio callback
integer-only. CV In 2 handles oscillator color so the Y knob can stay focused
on the effect. DubWarning.uf2 is the shippable PT2399-style delay version:
darker repeats, slight clock dirt, smeared feedback, and reverb-like wash at
longer settings. The Wheel Up gesture is fired from the switch and temporarily
overrides the free siren sweep with a short trilled pitch phrase and stronger
delay send. Audio In 2 uses jack detection, so the Main knob is only defeated
when a cable is patched.
Build in the repository dev container from this directory:
make
The dev container will configure CMake, build the firmware, and stage the UF2 in
UF2/.
Credits
- Dub Warning for the Workshop Computer by Adrian Vos, 2026.
- ComputerCard is the Music Thing Modular card library by Chris Johnson, MIT,
included here as
ComputerCard.h. - Music Thing Modular Workshop System Computer by Tom Whitwell / Music Thing Modular.
License
Dub Warning is released under the MIT License. ComputerCard.h
keeps its own MIT license and attribution to Chris Johnson.