Dustbox (Custom ZDL Effect for Zoom MultiStomp)

Dustbox is a custom DSP effect for Zoom MultiStomp pedals (MS-50G, MS-70CDR, etc.), written entirely in C.

It is a loving clone of the infamous DOD FX33 Buzz Box (rebranded here with a vacuum-cleaner theme). Under the hood, it combines a Grunge-style distortion in series with an MXR Blue Box. The result? A chainsaw fuzz running into a gated, synthetic sub-octave (two octaves down) generated by a zero-crossing flip-flop divider, just like the original CD4013 chip.

If you are looking for a clean, tracking sub-octave, look elsewhere. This is a glitchy, chaotic, roaring beast of a fuzz.

Parameters

The effect features 4 knobs, matching the layout of the original hardware:

1. Dust (0-100)
   • Blend between the raw distortion and the sub-octave fuzz.
   • This controls how much low-end 'dust' the vacuum is pulling in. It is the ONLY knob that adds the sub-octave. At 0, there is no octave present at all.
2. Motor (0-100)
   • Gain / Distortion amount.
   • Controls how hard the 'motor' is straining. This affects the distortion ONLY and never adds the octave. (Note: turning up the gain also makes the sub-octave tracking even more chaotic).
3. Filter (0-100)
   • Tone control (Single high-shelf).
   • 0 = Muffled / clogged filter (dark)
   • 50 = Flat
   • 100 = Clear / hissy filter (bright)
4. Power (0-100)
   • Master output level.

Installation

This effect is distributed as a pre-compiled .ZDL binary, ready to be flashed to your pedal. It runs natively on the pedal's DSP.

1. Download the Effect: Download the Dustbox.ZDL file from this repository.
2. Get Zoom Effect Manager (ZEM): You will need a community tool like Zoom Effect Manager (or similar tools compatible with ZoomMultistompZDL) to load custom files onto your pedal.
3. Load the ZDL:
   • Connect your pedal via USB.
   • Open Zoom Effect Manager.
   • Inject or drag-and-drop the Dustbox.ZDL file into the manager.
   • Sync/Write to the pedal.
4. Important Note: This effect is categorized under the Delay category (Internal ID: 0x08, FXID: 463). This makes it easy to find on models like the MS-70CDR.

⚠️ Warning: Always back up your pedal's patches and firmware before flashing custom .ZDL files.

Source Code

The source code for the DSP (dustbox.c) is included in the src/custom/dustbox/ directory.

Credits

This effect was made possible thanks to the incredible reverse-engineering work and DSP toolchain created by themanro. Massive thanks to them and all the contributors at themanro/ZoomMultistompZDL for paving the way for custom .ZDL development.

License

This project is licensed under the MIT License - see the LICENSE file for details.