OB-1
Pick OB-1 as a track's machine and its machine pages play two analog-style VCOs.
- Custom firmware
- Beta
- Medium brick risk
- Reversible
This project hasn't been claimed by its maintainer yet, so its details come from the community. Is it yours? Claim it
OB-1 0.6 adds Digitone mk1 / Digitone Keys support, contributed by x2k77m1, alongside the existing Digitakt mk1 machine.
What's new
- OB-1 on Digitone mk1 / Keys, OS 1.44. Two VCOs with saw/pulse waveforms and sub-octaves, hard sync, cross modulation and noise feed the Digitone's own filter, AMP envelope, mixer and effects.
- Fifteen controls across two SYN pages. SYN1 provides mixer/routing; SYN2 provides independent coarse/fine tuning, waveform family and shape for both oscillators. Custom page graphics, parameter locks, MIDI CCs and LFO modulation are supported. FUNC+turn restores OB-1 defaults or a held step's lock.
- Mono playing on each Digitone track. New notes take priority, with a retained pair of oscillators and a short handover crossfade. Releasing the newest note returns to the newest held note while its stock voice remains available.
- Both device packages are version 0.6. The Digitakt sound engine and control layout are unchanged from 0.5.
Downloads and installation
| Download | Device | Required stock OS | Required companion mods |
|---|---|---|---|
ob1-0.6-os1.54.elemod | Digitakt mk1 | 1.54 | Core and machine-pages |
ob1-dn-0.6.elemod | Digitone mk1 / Keys | 1.44 | Core for Digitone and machines |
Use Elekloader to combine the package and companion mods with your own matching stock OS. These downloads are mod packages, not complete firmware images. Digitakt OS 1.53 packages are not included in this release.
On Digitone, reselect OB-1 after updating from a development build; sounds saved with earlier development control maps may need their controls reassigned. Digitakt 0.5 sounds retain their parameter meanings.
Known limits
- Leave Digitone voices dynamically allocated for held-note return. Locking a track to one voice, or having an earlier note's voice stolen, can prevent return to that note.
- Releasing several held Digitone notes together can shorten the release tail depending on voice allocation. A fix is deferred to a follow-up.
- Digitone turn popups and LFO destination lists retain the borrowed FM parameter names.
Verification
Both packages passed stock-firmware lint/link checks, and both complete firmware images were built and verified locally. The host suite passed, including 49 regression tests and 42 Digitone adapter checks. Compiled Digitakt OS 1.54 firmware MIDI checks passed for all fifteen controls, defaults, note on/off, channel isolation and CC 9 reset. The DSP reference comparison remains at 307/311 passing, with the four documented XMOD mismatches unchanged.
Hosted CI is not green: its firmware build lacks the local Digitone OS 1.44 input, and the reference step reports the same four XMOD mismatches. The successful firmware builds and MIDI check above were run locally.
No fresh physical-device testing was performed for 0.6. The Digitone port's contributor-reported hardware checks are recorded in the support PR.
Full changelog: https://github.com/simonjohansson/elektrob-1/compare/ob1-v0.5...ob1-v0.6
Before you start
- How hard is it?
- EasyCopy a file or use a web page. No extra software.
- What you need
- A USB or MIDI cable
- Comfort with the command line
- A computer
- Can it break my device?
- Small chance of trouble, with a way to recover.
- Can I undo it?
- Yes. You can go back to the official software.
Did it work for you?
Did OB-1 ob1-v0.6 work on your Elektron Digitakt?
No reports yet for ob1-v0.6.
One-tap reports from owners. Bricked reports are checked before they count.
Compatibility
Devices: Elektron Digitakt.
No compatibility information yet.
Getting started
From the project's README ("Install"):
You need the stock OS file for the device you are building, from Elektron, and macOS or Linux with mise. Run mise bootstrap once for the m68k toolchain, tools, submodules and the emulator's dependencies.
Digitakt mk1
DigitaktOS1.54.syx (or 1.53's, with ELEKLOADERSTOCK in mise.toml pointed at it). The build patches it, and only its main OS section changes.
mkdir -p firmware cp ~/Downloads/DigitaktOS1.54.syx firmware/ mise run firmware:digitakt # builds everything and writes out/Digitaktcustom.syx
Digitone mk1 / Keys
DigitoneandDigitoneKeysOS1.44.syx, with DIGITONESTOCK in mise.toml pointed at yours. The build patches it the same way; the bootloader is never changed.
mkdir -p firmware cp ~/Downloads/DigitoneandDigitoneKeysOS1.44.syx firmware/ mise run firmware:digitone # builds everything and writes out/ob1-dn-1.44-0.6.syx
mise run firmware builds both devices and needs both stock files.
Flash it
With Elektron Transfer, as for any OS update (elekloader's steps):
- Connect the unit over USB and open Transfer.
- Select the unit and Connect.
- Drag the built file onto Drop files here (out/Digitaktcustom.syx or out/ob1-dn-1.44-0.6.syx).
- Press YES on the unit, and don't power it off until it has written the OS and restarted.
If it won't start
The bootloader is never changed, so the stock OS always restores the unit. On the Digitakt, hold FUNC while powering on, …
Risk and recovery
- Brick risk
- Medium
- Reversible
- Yes
- Requires opening the device
- No
From the project's README ("If it won't start"):
The bootloader is never changed, so the stock OS always restores the unit. On the Digitakt, hold FUNC while powering on, press TRIG 4 for OS UPGRADE, and send the stock file with Transfer's legacy OS upgrade mode. For the Digitone, use Elektron's OS-upgrade recovery for that unit.
Releases
| Version | Name | Released |
|---|---|---|
| ob1-v0.6 | OB-1 0.6Latest | 24 October 2026 |
| ob1-v0.5 | OB-1 0.5 | 19 October 2026 |
| ob1-v0.4 | OB-1 0.4 | 16 October 2026 |
| ob1-v0.3 | OB-1 0.3 | 14 October 2026 |
| ob1-v0.2 | OB-1 0.2 | 14 October 2026 |
| ob1-v0.1 | OB-1 0.1 | 14 October 2026 |