🎛️ OpenSL1 – Unofficial Rane SL1 (Serato Scratch Live) driver for macOS
Free, open-source, unofficial macOS audio driver for the Rane SL1
Use your Rane SL1 (the Serato Scratch Live interface) on Apple Silicon Macs again – scratch Serato timecode vinyl in Mixxx, or use the SL1 as a sound card in VirtualDJ.
💡 Why OpenSL1?
[!NOTE]
Which box is this? The original Rane interface for Serato Scratch Live from 2004 – a small box with
Input 1/2, Thru and Line jacks for two decks. It just said “Serato Scratch Live” on it; the name SL1 only came
later, when the SL2 and SL3 appeared. On USB it reports itself as Serato Scratch LIVE(c)2004 (13e5:0001).
Your SL1 still works. The software behind it doesn't: Serato Scratch Live is 32-bit Intel software, and Apple Silicon
Macs can't run it – not even through Rosetta. Serato DJ never supported the SL1 at all.
OpenSL1 is a native macOS audio driver for the SL1. Install it, plug in the box, and it shows up as a regular
sound card called “Rane SL1” – ready for Mixxx, the free DJ software that reads Serato
control vinyl.
[!NOTE]
OpenSL1 is an independent open-source project. It is not made, endorsed or supported by Rane, Serato or inMusic,
and it contains no code from them.
🧩 Which DJ software works with the SL1 on macOS?
You need the OpenSL1 driver for all of them – it is what makes macOS see the SL1 as a sound card. The DJ software on
top is your choice:
| Software | With the SL1 on macOS |
|---|
| Mixxx (free, open source) | ✅ Works – timecode on both decks, tested with Serato CV02 vinyl |
| VirtualDJ | 🟡 Opens the SL1 as a sound card and plays to Line 1 (tested) – see VirtualDJ setup. Timecode (DVS) needs a paid VirtualDJ licence and has not been tested. VirtualDJ has its own control vinyl and, according to community reports, also reads Serato CV02 – unverified here. |
| Serato Scratch Live | ❌ Legacy 32-bit Intel software – it does not run on Apple Silicon, not even through Rosetta |
| Serato DJ Lite / Pro | ❌ Does not accept the SL1. Only Serato could change that – OpenSL1 will never present the SL1 as another device |
✨ Features
| |
|---|
| 🎧 Plug & play | “Rane SL1” with 4 inputs (Input 1/2) and 4 outputs (Line 1/2) at 44.1 kHz |
| 💿 Timecode on both decks | Serato CV02 control vinyl in Mixxx, tested with real turntables and a DJ mixer |
| 🔌 Built for accidents | Cable pulled mid-set? Plug it back into any port – the music returns on its own |
| 🧷 Never loses your setup | “Rane SL1” stays available even when the box is unplugged – start Mixxx first, plug in later |
| 😴 Sleep-proof | Close the lid, open it again – sound is back 45 ms after wake |
| ⚡ Fast hardware path | 2.9 ms through USB and converters |
| 🩺 Gig diagnostics | Levels, gaps, USB errors and power events in the macOS log – see what happened during your set |
| 🛡️ Safe by design | No kernel extension; runs inside Apple's audio-server sandbox and never becomes your system output |
| 🍏 Universal | One installer for Apple Silicon and Intel, macOS 12 Monterey and later |
🔊 How it works
graph LR
A["💿 Turntables"] -->|timecode| B["Rane SL1"]
B -->|USB| C["OpenSL1 driver"]
C <-->|CoreAudio| D["🎛️ Mixxx"]
C -->|USB| B
B -->|Line 1 + 2| E["🎚️ DJ mixer"]
The SL1 is a USB audio interface underneath: OpenSL1 streams its inputs and outputs directly over USB and presents
them to macOS as a CoreAudio device. The audio clock comes from the SL1 itself, so nothing drifts.
📋 Requirements
| |
|---|
| 💻 Mac | Apple Silicon (M1 and later) or Intel |
| 🍏 macOS | 12 Monterey or later |
| 🎛️ Interface | Rane SL1 |
| 🎚️ DJ software | Mixxx (free, tested) – or VirtualDJ as a sound card |
| 💿 Control vinyl | Serato CV02 (Side A, 33⅓ RPM) – tested; other timecode vinyl is up to your DJ software and untested |
📦 Installation
- Download
OpenSL1-0.1.3.pkg from the latest release.
- Double-click it and follow the installer.
- Plug in the SL1 – done. It appears as “Rane SL1” in Audio MIDI Setup and in Mixxx.
[!IMPORTANT]
The installer is not “notarized” by Apple: Apple has not checked it, because that requires a paid developer account
(a free hobby project has none). That is why macOS shows a warning at first.
If macOS refuses to open it, go to System Settings → Privacy & Security and click Open Anyway.
Open OpenSL1-Uninstall-0.1.3.pkg from the same release. That's it.
Mixxx setup
| Where | Setting |
|---|
| macOS asks “Mixxx would like to access the microphone” | Allow – otherwise no timecode reaches Mixxx |
| Preferences → Sound Hardware | CoreAudio, 44100 Hz, buffer 5.8 ms (2.9 ms possible, see below) |
| Output: Deck 1 / Deck 2 | “Rane SL1” channels 1–2 / 3–4 |
| Output: Main, Headphones | None – your DJ mixer does that |
| Input: Vinyl Control 1 / 2 | “Rane SL1” channels 1–2 / 3–4 |
| Preferences → Vinyl Control | Serato CV02 Vinyl, Side A, 33⅓ RPM, mode REL |
| Vinyl Control → filter | Alpha-beta for scratching |
[!TIP]
Buffer: 5.8 ms is the safe default. 2.9 ms ran without a single error on a MacBook Air M4 (455 258
packets, 0 late accesses), but with a much smaller safety margin. Other Macs, heavy CPU load or other Mixxx versions
may crackle at 2.9 ms – test it before a gig.
[!TIP]
Alpha-beta beats Kalman for scratching. With the Kalman filter the track keeps running in slow motion for a
moment after you stop the record with your hand. Alpha-beta stops instantly – only the tempo display wiggles a bit,
you won't hear it.
[!WARNING]
Use the SL1 as your only sound card in Mixxx. If Main or Headphones go to the Mac's speakers or another
interface, Mixxx has to sync two clocks – that can cause crackles and skips.
Mixxx 2.6.0-beta on a MacBook Air M4. The buffer here is 2.9 ms – it works on this Mac, but 5.8 ms is the safe
default (see above).
VirtualDJ setup
[!NOTE]
Sound card: works. Timecode: not tested yet – only because VirtualDJ needs a paid licence (subscription) for
timecode/DVS, and we don't have one. VirtualDJ accepts the settings below; whether the timecode then runs is still
open. If you have a VirtualDJ licence, please report back in an issue!
| Where | Setting |
|---|
| Settings → Audio → Outputs | Separate decks: deck 1 → “Rane SL1” chan 1 & 2, deck 2 → chan 3 & 4 |
| Settings → Audio → Inputs | Timecode signal: timecode 1 → “Rane SL1” chan 1 & 2, timecode 2 → chan 3 & 4 |
| Settings → Timecode | Mode relative, Record Serato side A (CV02) – or VirtualDJ's own control vinyl |
| VirtualDJ (macOS, v2026) | Status |
|---|
| Finds and opens “Rane SL1” | ✅ tested |
| Music on Line 1 | ✅ tested |
| Changing the audio settings (6×) | ✅ tested – no hangs, no USB errors |
| Music on Line 2 | ❔ not tested yet |
| Timecode / DVS | ❔ not tested – needs a paid VirtualDJ licence (shows “Timecode: License needed”) |
| Serato CV02 vinyl in VirtualDJ | ❔ according to community reports yes – not verified here |
🎤 Gig checklist
📊 Performance
Measured on a MacBook Air M4 with real timecode:
| |
|---|
| ⚡ Hardware loop (USB + converters) | 2.9 ms – identical in every run |
| 🎚️ Record → line out (5.8 ms buffer) | ≈ 35 ms |
| 🔇 Signal-to-noise on the inputs | ≈ 41 dB (timecode −47 dBFS, noise floor −88 dBFS) |
| ✅ 15 min of timecode on both decks | 917 434 packets per input, 0 errors |
| 🔌 Replug during playback | sound back 0.3 s after macOS sees the SL1 |
| 😴 Wake from sleep | sound back 45 ms after wake |
❓ FAQ
Yes – OpenSL1 is a free, open-source CoreAudio driver for the Rane SL1 (Serato Scratch Live) on Apple Silicon Macs
with macOS 12 or later (the installer is universal, so Intel should work too – untested). Download the installer from the
latest release, plug in the box, and it appears as the sound
card “Rane SL1”.
No. Serato Scratch Live is legacy 32-bit Intel software, so it does not run on Apple Silicon – not even through
Rosetta. OpenSL1 replaces the missing driver; for the DJ software use Mixxx (free) or VirtualDJ.
Serato CV02 (Side A, 33⅓ RPM) is tested with Mixxx. VirtualDJ comes with its own control vinyl and, according to
community reports, also reads Serato CV02; Mixxx lists further timecode types in its vinyl-control settings. Those are
untested here: OpenSL1 only delivers the audio signal, decoding the timecode is up to your DJ software.
No. Serato DJ never supported the SL1 and does not accept it, and only Serato could change that. OpenSL1 will never
pretend the SL1 is a different device. Use Mixxx, or VirtualDJ with a paid licence.
Yes – the SL1 is a normal CoreAudio device, so any app can use it as a sound card. For VirtualDJ see
VirtualDJ setup. Timecode control is tested with Mixxx.
The installer contains a universal driver (Apple Silicon + Intel). It has been tested on Apple Silicon only – reports
from Intel Macs are welcome.
OpenSL1 is a user-space audio plug-in, not a kernel extension. It runs inside macOS's sandboxed audio service with
access to the SL1 only – no files, no network. The full source is in this repository.
Not supported yet.
You don't need OpenSL1 – Linux supports the SL1 out of the box. See docs/DEVELOPMENT.md.
🔧 Troubleshooting
Check the cable, then restart the audio service in Terminal: sudo killall coreaudiod.
The SL1 gets its power over USB and can briefly drop off when the Mac switches between charger and battery. The driver
usually recovers within about 3 seconds. Occasionally the SL1 hangs – unplug it and plug it back in, Mixxx can keep
running. Best practice: plug the charger in before the set. Ideas that might help, all untested and without promise: the SL1's
optional 9 V power-supply jack (the box would then not depend on the Mac's USB power – probably helps, but we can't
promise it), a direct USB-C to USB-B cable instead of an adapter, or a powered USB hub. A macOS power setting might
play a role too – not checked. Details in
docs/MACOS.md.
No problem since 0.1.1: “Rane SL1” stays available even when the box is unplugged, so Mixxx keeps its setup and
starts normally (silent). Plug in the SL1 – the sound comes within a second, no click needed.
Seen with Mixxx 2.6.0-beta and the SL1 (not with the Mac's built-in audio): the freeze is a deadlock between two
Mixxx threads while it stops the stream; the driver keeps running. We are still narrowing down the trigger. Until
then: force-quit and restart Mixxx, and set up sound before your set.
OpenSL1 is an audio plug-in, not a kernel extension, so a driver problem normally means “Rane SL1” disappears or audio
drops out – not that the Mac fails to boot. We cannot promise that every future macOS version works. If it breaks:
- Unplug the SL1.
- Open
OpenSL1-Uninstall-<version>.pkg from the release – or in Terminal:
sudo rm -rf /Library/Audio/Plug-Ins/HAL/OpenSL1.driver and sudo killall coreaudiod.
- Check the releases for a newer version, or open an issue with your macOS version.
If a Mac ever panics or will not start normally, start it without the SL1 and remove the driver as above. In the worst
case, start into macOS Recovery and delete OpenSL1.driver in Library/Audio/Plug-Ins/HAL on the system disk (exact
path in Recovery not verified). Make a Time Machine backup before big macOS updates, and test before a gig.
The driver writes a short report every 30 seconds. In Terminal:
/usr/bin/log show --last 2h --predicate 'subsystem == "org.opensl1.driver"'
🧭 Roadmap
🤝 Contributing
Tried OpenSL1 on another Mac or macOS version? Open an issue with your Mac model, macOS version and the log
lines above – every report helps. Building from source, test tools and internals:
docs/DEVELOPMENT.md.
OpenSL1 follows a strict clean-room rule: no code, binaries or disassembly from Rane or Serato software.
🙏 Acknowledgements
- OpenSL3 by mrbrainz proved that this kind of driver works for Rane gear
on Apple Silicon. OpenSL1 is written from scratch – no OpenSL3 code is included – but several robustness ideas
come from its changelog.
- Mixxx and its xwax-based vinyl control make all of this useful.
| |
|---|
| Mac | MacBook Air 13-inch, M4, 2025 (Mac16,12, 16 GB) |
| macOS | 27.0.1 (26A434) |
| Connection | passive USB-A → USB-C adapter |
| DJ software | Mixxx 2.6.0-beta |
| Vinyl / mixer | Serato CV02, two turntables, Pioneer mixer |
📜 License & disclaimer
GPL-3.0-or-later – see LICENSE.
[!WARNING]
Use at your own risk. OpenSL1 is an unofficial, independent hobby project and is provided “as is”, without
warranty of any kind. Installing and using it is entirely your own responsibility. To the extent permitted by law,
the author accepts no liability for damage of any kind – to your Mac, the SL1, other equipment, data, recordings or
performances (see sections 15 and 16 of the GPL).
- Unofficial. OpenSL1 is not the original driver. It is not made, endorsed or supported by Rane, Serato or
inMusic, and it contains no code, binaries or disassembly from them. The USB behaviour of the SL1 was measured on
our own hardware.
- Unsigned installer. The installer is not checked by Apple (not “notarized”). It installs an audio driver component
(
/Library/Audio/Plug-Ins/HAL/OpenSL1.driver) and asks for an administrator password. The full source is in this
repository; compare the installer with the SHA256SUMS of the release if you want to be sure.
- Hobby project. No guarantee of support, fixes, availability or compatibility with future macOS versions.
- Test before you rely on it. Check your setup well before a gig and keep a backup plan for paid performances.
- Other software and licences. Mixxx, VirtualDJ and any other software you use are subject to their own terms.
OpenSL1 does not circumvent licence checks and does not make the SL1 appear as another device.
- Privacy. The driver collects no data and has no network access.
- Donations. Support via Ko-fi is voluntary. It is a gift, not a purchase, and gives no claim to support,
features or warranty.
- Trademarks. Rane, SL1, Serato, Scratch Live and other names are trademarks of their respective owners and are
used here only to name the hardware and software this driver works with. OpenSL1 is not affiliated with, endorsed
by or supported by Rane, Serato or inMusic.
Made for DJs who keep their gear alive. 🎛️💿
If OpenSL1 saved your SL1, give it a ⭐
