Why does pattern playback do nothing?

The microSAMPLER's sequencer advances on incoming MIDI clock. Set GLOBAL > MIDI CLK = AUTO (or EXT MIDI) on the device so it follows the editor's transport.

Troubleshooting & FAQ

Q: Can I use it without a microSAMPLER?

Yes. Library mode opens bank backups (Korg .msmpl_bank files or this app's ZIPs) and extracts their samples as WAVs and patterns as MIDI, with no hardware. There is also a --mock mode for exploring the interface.

Common issues and fixes, the gotchas worth knowing, and answers to frequent questions.

Gotchas worth knowing

RAM vs. SAVED

Edits and uploads go to the device's current bank, which is RAM. They're lost on power-off or bank-switch. To keep them, do a WRITE on the device, or restore to a user bank from the editor. Back up your bank (Utility → BACKUP) before bulk operations, and never disconnect mid-transfer. More in RAM vs saved.

One USB owner at a time. Close other MIDI applications (and Korg's editor) while the bridge is running. Only one program can hold the device.
Pattern playback needs GLOBAL → MIDI CLK = AUTO on the device.
Remote sampling & record give no feedback in the editor, so watch the device screen.
Panel edits only transmit while the device is on its sample-edit page. Press RECEIVE (or refocus the window) to re-sync after fiddling with the hardware.

Troubleshooting

Symptom	Fix
"microSAMPLER not responding" / "no inquiry reply"	Usually a brief hiccup while claiming the USB connection, not a real fault. Click Retry in the panel first (the bridge also retries, including a USB reset, on its own). Only power-cycle the device if it keeps failing.
"BRIDGE OFFLINE"	The local bridge isn't running. Open the app (menu bar ♪ → Open Editor), or start the classic launcher (or `sudo python3 native-tools/bridge.py`). The page reconnects by itself.
macOS won't open the launcher ("unidentified developer")	Only the classic ZIP's launcher scripts are unsigned (the desktop apps are signed and notarized, with no approval dance). Approve the launcher once: right-click (Control-click) → Open → Open. On newer macOS without that option, double-click once, then System Settings → Privacy & Security → Open Anyway. See Getting started for the Terminal alternative.
Device not found / permission error	Run with administrator rights (the launcher does this), check the cable, and close any other MIDI app holding the device. On Windows, switch the driver to WinUSB with Zadig.
Edits made on the device don't show in the app	The microSAMPLER only transmits panel edits while it's on its sample-edit page. Press RECEIVE (or just refocus the window) to re-read the bank.
Pattern play does nothing	Set `GLOBAL → MIDI CLK = AUTO` (or EXT MIDI) on the device.
A connected MIDI keyboard doesn't play	Tick MIDI IN on the Samples view and approve the browser's Web MIDI prompt. Web MIDI needs Chrome, Edge or Firefox (not Safari).
Uploaded sample sounds wrong	The device plays 16-bit audio at fixed rates, and the editor resamples automatically. Re-upload if you changed the source file.
USB seems stuck after many reconnects	Power-cycle the microSAMPLER. Heavy connect/disconnect churn can wedge its USB firmware, which only a power-cycle fully resets.
macOS app won't reopen, launches slowly, or lingers in the background	Update to v1.15.1 or later, which fixes several app lifecycle issues (instant launch, clean quit, reliable reopen). After updating the Editor app it refreshes its background helper on the next launch. If it shows a one-time error right after an update, quit and reopen it.
Editor app opens the browser to "This site can't be reached"	The macOS Editor app serves the editor from a background service that needs a one-time approval — usually right after a fresh install or an update, and until it's approved the browser opens to a dead page. Enable it in System Settings → General → Login Items & Extensions ("microSAMPLER Editor Librarian"), then reopen the app. On v1.17.2 or later the app waits for the service and points you straight to that setting instead of showing an unreachable page.

FAQ

Is this made or supported by Korg?

No. It's an independent, unofficial project, not affiliated with or endorsed by Korg, and it contains no Korg software or firmware. The protocol was reverse-engineered for interoperability with hardware you own.

Why does it need administrator rights (sudo)?

Your operating system's MIDI driver normally owns the device's USB interface, so taking it over needs elevated rights. The macOS Editor app handles this with a background service you approve once (no typed password). The classic launchers ask for sudo each start. The Library app and library mode never touch USB, so they need no elevation at all.

Do my edits save automatically?

No. Edits go to the current bank, which is RAM. WRITE to a user bank on the device, or restore a backup into a user bank from the Utility view, to keep them across power cycles. Back up before bulk changes.

Can I use it without a microSAMPLER?

Yes. Library mode opens bank backups (Korg .msmpl_bank files or this app's ZIPs) and extracts their samples as WAVs and patterns as MIDI, with no hardware. There's also a --mock mode for exploring the interface.

Can I run it alongside my DAW?

Not at the same time. The device can only have one USB owner, and its sample/pattern transfers aren't ordinary MIDI. Close the DAW (and any other MIDI software) while the bridge is running, and close the bridge before using the microSAMPLER as a USB-MIDI device in your DAW.

Will it work on Windows?

It's experimental and untested there. libusb can't open the device until its USB driver is switched to WinUSB with Zadig. See Getting started.

Is my data safe?

The software is provided "as is", without warranty. It writes to the device's memory, so back up your banks before bulk operations and never disconnect mid-transfer. The author accepts no responsibility for any damage to your device or loss of data.

Didn't find it? Open an issue or check the changelog on GitHub.