GHOULBOX

Firmware for FM-1 (M-VAVE)

Dungeon-synth and dark-ambient groovebox on a Felucca 1.4.1 base: cathedral HALL reverb, worn-cassette TAPE effect, a hurdy-gurdy engine with buzzing trompette, drone latching, historical temperaments and dozens of dungeon sounds.

by Jason Persinger

ActiveSource: openGPL-3.0-only

GHOULBOX 2.0 – Dungeon Synth Firmware for the M-VAVE FM-1 (Free & Open Source) · GHOULBOX · via youtube.com · linked from github.com

Brick risk. Flashing this carries a known, documented risk of damaging the device.

Distribution: Browser installer (WebMIDI / WebUSB)
Source: github.com https://github.com/jasonpersinger/ghoulbox-fm1-dungeon-synth
Homepage: ghoulbox.messy.quest https://ghoulbox.messy.quest/

synth-engine
fx
performance
sequencer

Install notes

Browser WebMIDI installer (ghoulbox.messy.quest/webapp/installer/) that saves a full backup first. Browser emulator on the same site. An SMK-37 build exists in the genkigenki fork of Felucca.

Version history

GHOULBOX version history
Version	Date
2.1	2026-10-12
2.0	2026-10-12

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