DUELL 0.2.4 beta

DUELL
MultiMorphing Bitimbral Synthesizer
by OSCILL/R

Two synths in one small box. DUELL is free, open-source firmware (GPL-3.0) for the M-VAVE FM-1, a fork of Felucca. A bitimbral synthesizer with two independent parts, playable in three modes. This is the first firmware beta: the device package, the web installer and the browser emulator.

What is in it

• LAYER: both parts combined, with balance, velocity crossfade and key split. Perfect for complex sounds and DAWless performances.
• SPLIT: dual mono. Part 1 hard left, part 2 hard right, fully isolated for use with your external effects.
• STEREO: both parts in one stereo field.
• MORPH: glide between two versions of the same patch with one fader. A smart randomizer creates new variants from your starting point.
• 2 envelopes, 2 LFOs and a mod matrix with 8 slots. Every engine has a filter.
• Ducker (sidechain from MIDI), EQ per part, ping-pong delay, and the SHIM and RESO reverbs.
• MIDI: a channel for each part, clock in, program change, bank select.
• 97 patches, 16 MULTIs (both synths in one slot) and 16 patterns.

Full list: CHANGELOG.md.

Read this before you flash

• This is a beta. It has been tried on only one FM-1, the author's. Other units are untested.
• The FM-1 has a single-bank layout and there is no known rollback. The way back to the official firmware (V15) has worked on the author's unit about three times; it is not tested elsewhere.
• You install at your own risk. No warranty (GPL-3.0). Back up first, use a data USB cable straight into the computer, and never interrupt the write.
• DUELL is not affiliated with M-VAVE. M-VAVE's firmware is not distributed here: to go back you download V15 yourself from https://www.m-vave.com/download.
• Recovery notes: docs/RECOVERY.md.

Assets

File	What
duell-0.2.4-beta.fwsc	the device package (the installer page loads this one)
duell-emulator-0.2.4-beta.zip	the browser emulator (also hosted at https://oscillr.github.io/DUELL/emu/)
SHA256SUMS	checksums

783bcc49b0ba02c2c105d5f2b1e6b4d96538c85ef85a900ab796d1b6f77df4f6  duell-0.2.4-beta.fwsc
7775abee8f30679331d5e09f5b5433b7525a2a1392a3ff2d3e822a8186ea87af  duell-emulator-0.2.4-beta.zip

How to install

Open the installer page in Chrome or Edge on a computer: https://oscillr.github.io/DUELL/install/. Tick the checklist, save a backup, connect the FM-1, press Install and wait for Done; then unplug and replug the unit. Steps and details: docs/INSTALL.md. The page compares the file with the SHA-256 above.

Known gaps

• The backup does not include MULTIs and PATTERN slots; restore is untested.
• Very rarely a short click (a missed audio block) when switching to a very heavy multi.
• The editor in the source tree is not adapted to DUELL.
• Tested on one unit only; MIDI is not tested with many devices; dual core is off and untested.

All of it in docs/KNOWN_ISSUES.md. Bugs: the report form.

DUELL 0.1 beta (emulator)

DUELL
MultiMorphing
Bitimbral Synthesizer
by OSCILL/R

This is the first public beta of DUELL, a free, open-source bitimbral firmware for the M-VAVE FM-1. It is based on Felucca.

What is in this release
The browser emulator only. Download the zip, or just open the hosted version at https://oscillr.github.io/DUELL/emu/ once the page is live.

• Two complete parts, playable in three modes: LAYER, SPLIT and STEREO
• MORPH between two versions of every patch, with a smart randomizer
• 12 sound engines and a factory palette of about a hundred sounds
• Two envelopes, two LFOs and an 8-slot modulation matrix
• Ducker with MIDI sidechain, EQ per part, ping-pong delay and the SHIM and RESO reverbs
• 16 multis and 16 patterns

What is not in this release
There is no firmware download yet. The firmware has run on one real FM-1, but the way back to the official firmware has not been tested yet, and more hardware testing comes first. Please do not try to flash anything for now.

Good to know

• The emulator keeps its data in your browser. After an update, clear the site data for the page. "Download saved data" makes a backup first.
• Browser MIDI forwards notes, CCs and program change, but not clock or SysEx.

Feedback
Bug reports and ideas are welcome in the Issues tab. There is a bug form with the details that help most. Please say which browser and which part of the emulator you used.

DUELL is licensed GPL-3.0-only, like Felucca. No warranty. It is not affiliated with or endorsed by M-VAVE. Thanks to Baud Girl, Leo Kuroshita and the whole community. The SHIM and RESO reverbs come from JIANT.

SHA-256 of duell-emulator-0.1-beta.zip:
cba20fc695f3fed335b52ebd077d0a791cfe06b7662257ee7678295382a4d52f