Tone+FX — development source

A master effect suite for the Digitone mk1 / Digitone Keys (OS 1.43 and 1.44).

This is the development/source repo (remote still named RingTone). The release repo — built .elemods, docs and packaged releases — is Tone+FX. Download the latest release from github.com/DigiAlchemydsp/Tone-FX/releases.

Unofficial, community-made elekloader mods for the Elektron Digitone mk1 / Digitone Keys, OS 1.43 / 1.44. (A community port of the same suite for the Elektron Digitakt mk1, OS 1.53 / 1.54 is maintained by gdeo607 in digi1_mods, vendored in the release repo under DIGITAKT PORT/.)

What it is

Tone+FX is a set of elekloader mods (.elemod) that install together. They process the master mix on the Digitone's main CPU — the same stage the firmware runs its own effects on: after the eight FM voices have been mixed and before that mix is handed to the analog outputs and to the USB stream. So every output carries them. The FM voices themselves run on the Digitone's second CPU, which these mods do not touch.

Permanent chain:

ring → EQ → crush → fold → PITCH → DELAYS (WRMZ/GRAINZ) → STEREO → ceiling → meter

digictl requires the FX mods, so install them as a set (build with core-dn1 4.0 plus the suite, or just mods/tonefx).

Unofficial and unsupported. Not affiliated with, endorsed by or supported by Elektron. Flashing modified firmware is at your own risk. No firmware is distributed here.

Use

The pages live on the master page tree: FUNC + LFO opens it.

• Main scroll (LEFT / RIGHT): the stock master pages, then our FX pages in play order FOLD - CRUSH - RING - STEREO - PITCH - TILT - DELAYS.
• Macro tree (UP): PERFORM - WASH - RADIO - DESTROY - SPACE (LEFT/RIGHT cycle within it; UP returns to the FX page you left).

The stock top status bar stays above every page. PAGE keeps its stock meaning; no stock key or encoder is taken. A page whose section is off draws a framed OFF box; a page driven by a macro draws a MACRO box. FUNC + an encoder turn snaps that parameter to 0 % / 100 %.

• RING — A on/off, E depth, F frequency.
• FOLD — A on/off, D fold type, E/F/G/H amount, LEVEL meter.
• TILT — A on/off, E low shelf, H high shelf (64 = flat).
• CRUSH — A on/off, D mode (BITS/REDUX/CRUNCH), E amount, F tune, LEVEL meter.
• PITCH — A on/off, D mode (WOB/SHFT), E speed, F depth, G mix.
• STEREO — A on/off, D mode (FLAN/PAN/WIDE), E speed, F depth, G mix, H feedback.
• DELAYS — A on/off, D mode (WRMZ/GRAINZ), B/C/E/F/G/H the active mode's six params; true bypass off; mono wet.
• PERFORM — static page, A–H one depth per engine; the 16 trigs are momentary performance pads.
• WASH / RADIO / DESTROY / SPACE — one-slider macros. WASH = WOB only (75 % depth / 30 % rate) + the WRMZ delay's MIX/FB; RADIO = EQ tilt (low → 0, high → 127) + TRSH fold + SRR-only crush; DESTROY = fold + bits + ring; SPACE = WAVE stereo width. Capture/restore is per engine, so CRUSH/REDUX is not tied to WASH.

Every parameter is 0–127 and moves one step per notch, the stock convention (EQ LOW/HIGH show 0–127 with 64 = flat). The FX also respond to incoming MIDI CC; see docs/MIDI-CC.md.

Pages

Twelve master pages (FUNC + LFO; LEFT/RIGHT rotates; UP opens the macro tree). Each FX page has a frameless animated graphic that collapses at neutral; PERFORM is static; the macros each show one slider + a graphic. Per-pattern settings are packed into one reserved MIDI track (t=7, pattern+0x1BB0, "DGX4", CH 16) and save/reload with the pattern; see docs/PATTERN-STORAGE.md.

RING	FOLD	TILT

CRUSH	PITCH	STEREO	PERFORM

CPU footprint

Everything runs on the Digitone's main CPU (Core A); the FM DSP (Core B) is untouched. A bypassed section costs ~0. The DELAYS line is the largest single cost (mono s16, WZ_N=2^14); the 4.0 line runs its per-frame gains on the eMAC (src/emac.h) and uses s16 wave lines. WASH uses a static WRMZ read (MOD=0) and skips the DC blocker while on.

Full ledger: docs/OPTIMIZATION-ROUND.md (historical docs/OPTIMIZATION.md, PERF-OPT-PLAN.md). Output ceiling: a final soft limiter keeps the mix below 24-bit full scale (transparent below ~-2.5 dBFS, asymptotic max ~-0.7 dBFS).

Layout

src/            corea.h, buffx.h, emac.h, sin256.h (shared helpers)
mods/<id>/      mod.json + sources
mods/tonefx/    the merged 4.0c suite (format 2; requires the core, no core inside)
docs/           pattern storage, MIDI CC, the CPU ledger, plans
releases/       older RingTone snapshots (current releases live in Tone+FX)
LICENSE         GPL-2.0

Getting it

elekloader builds a custom OS on your machine from your own stock Digitone_and_Digitone_Keys_OS1.43.syx plus these mods; it never distributes firmware. New releases live in Tone+FX.

Building from source

The suite ships as one merged mod, mods/tonefx/ (it requires the core, which it does not include). One source builds both OS versions; the stock file picks the release (ports.1.44 in mods/tonefx/mod.json). --version must be exactly 4 ASCII characters.

$env:PATH = "C:\SysGCC\m68k-elf\bin;" + $env:PATH
$env:ELEKLOADER_CROSS = "m68k-elf-"
$env:PYTHONPATH = "<elekloader checkout>"

# OS 1.43 -> out/tonefx-4.0c.elemod
python -m elekloader.sdk.build "mods\tonefx" --stock Digitone_and_Digitone_Keys_OS1.43.syx
python -m elekloader.patch --stock Digitone_and_Digitone_Keys_OS1.43.syx `
  --mod core-dn1-4.0.elemod `
  --mod mods\tonefx\out\tonefx-4.0c.elemod --out ToneFX-1.43.syx --version 4.0c

# OS 1.44 -> out/tonefx-4.0c-os1.44.elemod
python -m elekloader.sdk.build "mods\tonefx" --stock Digitone_and_Digitone_Keys_OS1.44.syx
python -m elekloader.patch --stock Digitone_and_Digitone_Keys_OS1.44.syx `
  --mod core-dn1-4.0-os1.44.elemod `
  --mod mods\tonefx\out\tonefx-4.0c-os1.44.elemod --out ToneFX-1.44.syx --version 4.0c

The components (digimeter, digieq, digiring, digifold, digicrush, digiwave, digiwrmz) can still be built and combined individually.

Status

Current source: Tone+FX 4.0c (twelve pages incl. DELAYS; PERFORM + the four macros; per-pattern store "DGX4"; MIDI CC). The 4.0c Digitone build is byte-identical to the published Tone+FX v4.0c elemods. Verified in digiemu (boot/settle, dsp_running=2, all pages, the store round-trip, the macro values, 0 faults). See HANDOFF.md for state and open items.

Testing

python tests/digiemu_pattern_store.py --fw <dn1-...> --map <syx.map.json>   # store regression
python tests/digiemu_nav.py --fw <dn1-...>                                  # page navigation
python tests/digiemu_midi_cc.py --fw <dn1-...> --map <syx.map.json>         # MIDI CC hook
python tests/_timing_buffx.py --fw <dn1-...> --map <syx.map.json> --ms 120  # CPU margin
python tests/_timing_wave.py  --fw <dn1-...> --map <syx.map.json> --ms 120  # wave modes
python tests/_probe_mix.py --fw <dn1-...> --map <syx.map.json>              # WOB/SHFT/FLAN/WIDE

(The digiemu_* tests need the patched-Unicorn venv; --fw is a firmware the app built from core-dn1 + the mods.)

Parked / future work

• WASH delay CPU: half-rate WRMZ wet, mono WOB, or a delay-time cap (audible trades); then 4-accumulator MAC interleaving and eMAC on fold/crush Q8.
• Sequencer p-lock automation for the FX params (branch tonefx-plock).
• Per-voice filter rewrite + digimachine (branch filter-and-digimachine).
• LFO destinations / audio-chain reroute (docs/MODULATION-AND-ROUTING.md).
• FAST AUDIO on the DN (docs/FAST-AUDIO-DN.md).

Licence

Our own code and docs: GPL-2.0-or-later (LICENSE). This does not cover the manufacturer's firmware, which is never distributed here.