Les

FM-1 firmware · 2.8-kitten.4

Kitten Synths

A live groovebox with four synth parts and drums, adding a Minimoog-style synth with a hundred sounds and per-track recording into a computer.

Made by
Black Kitten Devices
Released
October 30, 2026
Built on
SLOOP
Install
On the FM-1 Firmware Hub · source on GitHub
Scan
Scanned, nothing harmful found · Oct 31 What we checked
Last checked
October 31, 2026

What Kitten Synths does

  • Thirteen engines cover 250 sounds, led by MUUG, a Moog-style three-oscillator synth with 100 factory sounds and a ladder filter.
  • Build MUUG sounds on the FM-1 itself across oscillator, mixer, modulation and filter contour pages, kept as your OWN patch.
  • Play three synth tracks, a grey LITE synth part and drums together, picking each with the ALGORITHM knob.
  • The drums give 16 sounds on the white keys, 37 kits, ghost and loud hits, and your own sampled kits.
  • Press REC to overdub while the loop runs, with 64 steps per track, parameter locks, swing, nudge and a piano roll.
  • Store loops into sections A to D, chain them live and record a whole song as you play it.
  • Autosave catches your work after a short pause, including the LITE part and your MUUG patches, and restores it at power-on.
  • USB carries eight audio channels, the stereo master plus every synth track and the drums, for separate recording in a DAW.

Its modes

HOME
Shows the five tracks, opens the full-screen visualizer, and held, opens the settings menu.
FX
Hold it and the keys fire 27 punch-in effects over the whole mix, with DUST and DUCK on the knobs.
EDIT
Hold it to erase a sound or note while the loop plays, and shift, double or transpose it.
ARP
Hold it for note repeat on the grid, with RATE on the first knob.
SEQ
Hold it to toggle the 16 steps of the page and set sound, division, swing and length.
SEL
Hold it to pick the song's key, chord, scale and transposition.
GLO
Hold it to mute and solo the five tracks, set their levels, tap tempo and trigger a fill.
SAVE
Hold it to play sections A to D, store loops into them, chain them and record a song.
DRUMS
Shows the step grid for the chosen drum sound and the kit, with TUNE and DECAY per sound.
REC
Sets recording mode, loop length, start and quantize before your first note.

What Les checked

Kitten Synths v2.8-kitten.4Scanned 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

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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