Ableton Link on the SP-404 MK2 and P-6 — No USB Cable to Your iPad

If you own a Roland SP-404 MK2 or a P-6 (or pretty much any class-compliant groovebox), you've probably hit the same wall I hit:

You want to jam with your iPad — Koala, AUM, Drambo, Loopy Pro, GarageBand. Or you want your hardware to lock to Ableton Live on your laptop. Or you've got a Push 3 across the room. All of those speak Ableton Link.

Your SP-404 doesn't. Your P-6 doesn't. Roland never built Link into them. There's no Link Bluetooth dongle for them. You're stuck running a USB cable to your phone (which iPads don't even allow audio class on) or syncing manually and praying.

Until now.

What Compa v0.1.1 just shipped

Compa is a Raspberry Pi touchscreen companion I've been building for the SP-404 MK2 and P-6. As of v0.1.1 (out 2026-05-02), Compa is a full Ableton Link peer.

What that means in practice:

- Compa joins any Link session on your local network — iPad apps, Ableton Live, Push 3, other Link-aware peers. - Compa rebroadcasts the Link tempo as standard MIDI clock (0xF8 at 24 PPQN) to every connected USB MIDI device. - Your SP-404, P-6, or any class-compliant groovebox plugged into Compa via USB follows that clock. - Set the groovebox's sync source to External or Auto. Done.

Path is: iPad on WiFi → Compa's Link peer → Compa relays MIDI clock over USB → your sampler.

No cable from the iPad to your sampler. No host-mode hack. No "what hub do I use." A Pi sits between your phone and your gear and does the bridge.

Multi-Compa mesh

If you've got two Compas — one driving an SP-404, another driving a P-6 across the room — they see each other on the network and stay locked together as Link peers. Tempo changes propagate. Stop and start propagate.

Setup

If you already have Compa running, update via Settings → Updates. The 0.1.1 release pulls down with the new Link section.

In Settings → Ableton Link:

- Enable Link toggle - Send MIDI Clock toggle - Live status showing tempo source ("from this Compa" or "from a Link peer") - Per-device list showing which connected USB devices are receiving the clock

The session screen gets a green LINK indicator that pulses on every tempo / peer update.

Why this matters

The hardware-producer side has the gear we love (404, P-6, Volcas, MPCs). The iPad / DAW side has Link, networked sync, everything timing-related solved. Bridging the two has historically required a Mac in the middle, MIDI cables, and a phone tethered with the wrong adapter.

Now it doesn't. A Pi runs the bridge. Everything stays locked.

What's next

The follow-up I'm working on is Link Audio — Ableton's audio-streaming-over-Link spec coming with Live 12.4. The plan is to bridge audio from Compa to Live over WiFi, so you can route your SP-404 or P-6 into a Live session as a network audio source. Pi 5 already runs it end-to-end in dev. Public Compa release once the timing is right.

Get Compa → — open source, MIT licensed. Free image, runs on a $35 Pi.