Les

FM-1 firmware · v0.23-j6

ChoralRoot J-6

The ChoralRoot chord instrument with a hundred preset chord sets in the style of the Roland J-6, so one key plays a voiced, voice-led chord.

Made by
EremanSim
Released
October 13, 2026
Built on
ChoralRoot
Install
On GitHub
Scan
Scanned, nothing harmful found · Oct 31 What we checked
Last checked
October 31, 2026

What ChoralRoot J-6 does

  • One hundred chord sets give each of the twelve keys a ready voiced chord with extensions and slash basses.
  • With a set on, the left nine keys become set controls for SET, GENRE, TRANSPOSE, HOLD and PHRASE.
  • Six synth engines hold 144 factory sounds: FM6, FM TONE, VA, CZ-1, WHEEL and PHYS.
  • PRESETS turns through all 144 sounds as one list while a set is on, engine by engine.
  • The looper records chords rather than audio across ten slots, with overwrite, overdub, replace and step entry.
  • Strum, Slop, Arpeggiate, Pattern and Harp play your chord for you, with reverb, chorus, delay and drive behind them.
  • SAVE keeps up to 32 of your own sounds, and the chosen set returns after you switch off.
  • USB carries MIDI both ways and a six-channel audio input, and the TRS jack takes MIDI in.

Its modes

LOCK layer
Set whether a type key clears the latched extensions and whether extension keys toggle or work as a pushed set.
KEY layer
Pick the tonic, scale, transpose, the split and whether the keybed plays chords or 27 single notes.
BASS layer
Choose the bass behaviour, register, sound and level for the second monophonic part.
PERF layer
Pick Strum, Slop, Arpeggiate, Pattern or Harp and turn its four parameters while the keys play.
METRO layer
Choose the time signature of 4/4, 3/4 or 6/8 and set the click level.
PLAY menu
Pick the loop slot, record mode, take length, quantize, count-in and loop level.
engine picker
Preview the six engines and their pools, then keep or cancel the sound you chose.
sound editor
Edit the current patch through the OSC, FILT, ENV, LFO, MOD, FX and MIX groups.

What Les checked

ChoralRoot J-6 v0.23-j6Scanned October 31, 2026

What we checked for

  • The file is exactly the one its author published
  • It's the same file we saw when this release first came out
  • It opens cleanly as an FM-1 firmware, nothing damaged
  • It doesn't show up on your computer as a keyboard, mouse or other input device
  • It doesn't show up as a USB drive or network adapter
  • Its text mentions no computer command tools, like PowerShell, Terminal or a download command

What we found

  • MIDI and audio, as expected
  • A serial port, which many FM-1 firmwares keep for debugging. It can't type into your computer.

StatusScanned, nothing harmful found

Les scans every firmware here whose file is public, and shows what it checked and what it found. A scan lowers the risk; it can't rule it out. This firmware is made by its author, not by Les or M-VAVE. Back up first, and install at your own risk. How Les scans firmware

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