GRID — 8-Pad Sampler for Percussa SSP

GRID is a performance sampler plugin for the Percussa SSP Eurorack module. Eight pads, deep editing, modular integration.

License: AGPL-3.0
Author: Andy Kuttor (@kuttor)
Platform: Percussa SSP (ARM Cortex-A17, 1600×480 display)
Version: 2.4.0-beta

Features

Sampling & Playback

• 8 independent sample pads with per-pad file loading
• Multi-voice polyphony (4 voices per pad) with voice stealing and crossfade
• Play modes: One-Shot, Loop, Clocked Loop, Clocked One-Shot
• Sample start/end with visual trim
• Reverse playback
• File browser with Smart Home, auto-preview, multi-select, and file operations

Slice System

• Transient detection with LOW/MED/HIGH sensitivity
• Manual slice placement with undo
• Auto-slice presets (8, 16, 24, 32, 48, 64, 128, Transient)
• Per-slice pitch offset
• Destructive delete (tape-cut splice)
• Slice export to individual files
• CV-driven slice selection (2 assignable CV inputs)
• MIDI note-to-slice mapping

Time Stretch & Pitch

• WSOLA time stretch with cross-correlation grain alignment (default)
• Legacy OLA mode selectable per pad
• Pitch control with quantize mode (push encoder to toggle, displays note names)

Filters

• TPT SVF: LPF, HPF, BPF, Notch
• Formant filter
• MS-20 style filter
• Buchla LPG: vactrol envelope with memory effect, coupled 6dB/oct filter + VCA

Lo-Fi Modes

• 8-bit, 12-bit, SP-1200 emulation, MPC-60 emulation

MOD Tab — Per-Pad Step Modulation

• 3 independent mod slots per pad (Mod A / B / C)
• 7 targets: Velocity, Pitch, Start, End, Filter, Pan, Stretch
• 5 actions: Increase, Decrease, Ping/Pong, Random, Sample/Hold
• 16-step pattern that advances on every trigger
• Mod editor popup with pixel art icons and 2x8 step grid
• 2x4 block selection matches SSP physical button layout
• 10 presets per mod slot with auto-save on editor close

Bus Compressor

• SSL-style feedback topology with soft knee
• Dual-time-constant auto-release
• Sidechain HPF, tanh saturation drive
• Gain reduction visualization overlay on pads

Performance

• Mute/Solo with configurable fade time
• Choke groups (A-H)
• Performance modes: Immediate, On Release, On Bar
• Kit save/load system with random name generator
• Program Change kit switching (MIDI PC or configurable CC)
• Stack files (Round Robin, Random, Velocity Split)

MIDI

• Per-pad MIDI channel assignment (1-16 or Omni)
• Per-pad CC mapping (Slice, End, Volume, Pan, Stretch, Filter)
• MIDI clock sync with division/multiplication

Modular I/O

• 24 inputs: per-pad trigger + pitch CV, clock, reset, slice CV, record, filter CV
• 10 outputs: stereo mix + 8 individual pad outputs
• Per-pad output routing with mix send toggle

Building

Requirements

• ARM cross-compiler: arm-linux-gnueabihf-g++
• JUCE framework (included via CMake)
• SSP SDK (in libs/ssp-sdk/)

Build (macOS to SSP)

cd ~/Code/Percussa-SSP--GRID

# First build compiles objects + creates helper
make -j$(sysctl -n hw.ncpu) 2>/dev/null || true

# Fake the VST3 helper (can't run ARM binary on Mac)
echo '#!/bin/bash
exit 0' > juce_vst3_helper
chmod 755 juce_vst3_helper

# If helper not in PATH:
sudo cp juce_vst3_helper /usr/local/bin/juce_vst3_helper
sudo chmod 755 /usr/local/bin/juce_vst3_helper

# Build VST3
make GRID_VST3

# Strip for deployment
arm-linux-gnueabihf-strip GRID_artefacts/Release/VST3/GRID.vst3/Contents/armv7l-linux/GRID.so

Deploy

Copy GRID.so to your SSP's SD card:

/media/BOOT/plugins/GRID/GRID.so

I/O Layout

Inputs (24):

Outputs (10):

Pages

File Structure

/media/BOOT/
├── plugins/
│   └── GRID/
│       └── GRID.so
└── samples/
    ├── kits/           <- .kit preset files
    ├── stacks/         <- .stack multi-sample files
    ├── recordings/     <- recorded samples
    └── [your samples]

Credits

• TheTechnobear (Bear): SSP SDK guidance, Midi Research and a bunch of other amazing SSP contributions.
• wavejockey: Lead Tester & Documentation
• Handsonicsuki: Tester
• ahabzutun: Tester

GRID uses the JUCE framework and the Percussa SSP SDK.

License

GNU Affero General Public License v3.0 (AGPL-3.0). See LICENSE.