PGB-1 Compact Open-Source Groovebox (Metal)

This pocket-sized powerhouse squeezes a full groovebox into a credit-card footprint—100x66x15mm—of rugged metal, powered by a rechargeable Li-ion battery for untethered jams anywhere.

At its heart, six digital synthesis channels and two samplers deliver drums, bass, leads, and polyphonic chords (up to four voices on one track), fueled by a Raspberry Pi RP2040 dual-core processor and Cirrus Logic WM8960 audio codec for crisp 32-bit/48kHz sound. Shape tones with per-channel LFOs, onboard filters, and four master effects like reverb, overdrive, and bitcrush, then sequence it all across 16 tracks (eight internal sound/MIDI, plus extras) with 16-step patterns, song mode, chord/arpeggiator generators, probability, ratcheting, and live effects. Hands-on control comes via 30 tactile switches, 25 RGB LEDs for visual feedback, a 128x64 OLED screen, capacitive touch strip, and built-in mic for instant sampling—plug in via 3.5mm stereo out/headphones, mono line-in, MIDI I/O (TRS-A), or USB-C for power/data and web-based sample import. A 1W stereo speaker and open-source firmware (CircuitPython/C++) invite deep customization.

Since shipping, it's earned praise from hackers and musicians for its dense feature set and tweakability in such a tiny package, though some note the button grid takes practice for live fluidity.