Overcast

Overcast by Padbangers is a texture synthesizer for Akai MPC standalone devices: Mutable Instruments Clouds with Matthias Puech's Parasites firmware, as a native MPC OS insert effect, with a modulation page on top.

• Six modes: Granular, Stretch, Looping Delay, Spectral, Oliverb, Resonestor — the knob names follow the mode.
• Modulation: two ADSR envelopes, two LFOs (seven shapes, free or synced to the MPC tempo) and an 8-slot matrix onto the module's CV inputs: Position, Size, Pitch, Density, Texture, Blend, Spread, Feedback, Reverb, Freeze and Trigger.
• Play it melodically like the module's V/OCT and TRIG inputs, from a MIDI track.
• In/Out Gain with an output limiter, Q-Link support on every page.
• A built-in manual on its own tab: basics, MIDI, modulation and every mode.

Requirements

• A first-generation MPC OS standalone device with a 32-bit ARM CPU: MPC Live / Live II, One, X, Key 61, Force. Developed and tested on an MPC X.
• Root SSH access to the device. Stock MPC OS doesn't offer this; you need a modded unit.
• Installing plugins this way is unofficial. Back up your projects and use it at your own risk.

Install

1. Download Overcast-<version>-mpc-armv7.zip from the Releases page and check its SHA-256 against the release notes (shasum -a 256 <zip> on macOS/Linux, certutil -hashfile <zip> SHA256 on Windows).
2. Unzip it and copy the folder to the device:

   unzip Overcast-1.0.0-mpc-armv7.zip
   scp -r Overcast-1.0.0 root@<device-ip>:/tmp/

3. Save your project, then run the installer. It stops MPC, copies the plugin, backs up MPC.settings, adds Overcast to the plugin list and starts MPC again:

   ssh root@<device-ip> sh /tmp/Overcast-1.0.0/install.sh

4. Insert Overcast as an insert effect on any track (Insert effects, manufacturer Padbangers).

Update: run the new version's install.sh the same way. Remove: sh /tmp/Overcast-<version>/uninstall.sh.

Using it

OVERCAST tab: pick the mode at the top. Q-Links:

Position	Size	Texture	In Gain
Density	Pitch	Spread	Out Gain
Blend	Feedback	Reverb	Freeze
Mode	Quality	MIDI Pitch	Reverse

Tips: in Granular, Density at 12 o'clock means no grains (counter-clockwise: steady rate, clockwise: random). Freeze stops recording into the buffer — with Blend below 100 % you still hear the dry input next to the frozen cloud.

MANUAL tab: a short manual on the device: basics, MIDI, modulation and each mode.

MODULATION tab: envelopes and LFOs on the left, the matrix on the right (source → destination → amount, −100…+100 %). With SYNC on, an LFO's rate knob picks the note value (4 bars … 1/32) and shows it under the knob. Freeze and Trigger destinations are gates: on above 50 %. An LFO square wave on Trigger clocks grains (or strikes the Resonestor) in time with the MPC.

MIDI (melodic playing): MPC OS sends no MIDI to insert effects, so every Overcast instance opens its own MIDI input, Overcast 1, Overcast 2, … Make a MIDI track, set its output to Overcast 1, and play: each note is a trigger, and with MIDI Pitch on it transposes relative to C3 (like V/OCT). Classic setting: Freeze on, Density at 12 o'clock — every note plays a grain at its pitch. In Resonestor, notes play the resonator and switch its two voices. Envelopes set to MIDI follow these notes too.

The Q-Link display shows <program name> (<parameter>): rename the track's program to "Overcast" to read "Overcast (Position)". After replacing the plugin file by hand, restart the MPC app — re-inserting the plugin doesn't always load the new file.

Differences from the module: it runs at the MPC's 44.1 kHz instead of 32 kHz (pitch is right; the buffer is about a quarter shorter and time constants are a little faster).

Build from source

Needs Docker (with QEMU for 32-bit ARM containers), Python 3 and bash ≥ 4. The plugin framework is a submodule:

git clone --recursive https://github.com/padbangers/overcast
cd overcast
./build.sh            # -> build/overcast.so + skin
./deploy.sh <host>    # copy to a device over ssh (--yes also registers it; restarts MPC)

The skin is generated: python3 skin/gen_layout.py (layout), python3 skin/gen_params.py (modulation params). Developer notes, device findings and design decisions: CLAUDE.md.

Credits and licenses

• Overcast: MIT, see LICENSE.
• Clouds DSP by Emilie Gillet, Parasites firmware by Matthias Puech — MIT, vendored in third_party/parasites/.
• Plugin framework: sd88me/mpc-vst-plugins (submodule; build-time only).
• Not affiliated with Mutable Instruments or Akai Professional.