Recording with OP-1 Field and iPhone

You need three things to record the OP-1 Field into Reel. The OP-1 Field itself, an iPhone running iOS 18 or later and a USB-C to USB-C cable.

USB-C iPhones (iPhone 15 and later) need no adapter. For Lightning iPhones you need Apple's Lightning to USB 3 Camera Adapter.

By default the OP-1 Field sends 2 channels over USB, a stereo mix. To record all 4 tracks separately you have to switch it to 8ch mode.

On the OP-1 Field, go to System, then USB MODE and set it to 8ch. That exposes 8 mono channels over USB. Tracks 1 through 4 in stereo pairs (1L/1R, 2L/2R, 3L/3R, 4L/4R).

Connect the OP-1 Field to your iPhone with the USB-C cable. Open Reel. The app detects the OP-1 Field automatically as an 8-channel input device.

In the Input settings you can route each OP-1 Field track to a separate Reel track. Track 1 of the OP-1 goes to Track 1 of Reel and so on.

Arm all 4 tracks in Reel, hit record and play your arrangement on the OP-1 Field. Each OP-1 track is captured to its own Reel track in 32-bit float.

Now you have 4 independent stems. Rebalance them on the mixer, overdub, then share the project and each track prints as its own stem with the mix, pitch and loop baked in. The same cable carries MIDI, which is the part that makes multi-pass work stack properly. Reel follows the OP-1 Field's transport and clock in both directions, with tempo follow, song position and return to zero, and this is the machine we tested it against. Long-hold Rec to arm a take and pressing play on the OP-1 rolls it, so every pass starts from the same place rather than from your thumb.

The original OP-1 only sends 2 channels over USB. You cannot record all 4 tracks at once. So you record track by track instead.

On the OP-1, mute tracks 2, 3 and 4, then arm Reel track 1 and record. Rewind Reel. Unmute OP-1 track 2, mute the others, arm Reel track 2 and record again. Repeat for tracks 3 and 4. Now you have 4 separated stems in Reel.

Once the OP-1 Field tracks are in Reel you can overdub new parts right in the app. Plug a microphone or instrument into another channel of your USB interface or do a second pass through the OP-1.

Reel lets you punch in and out at any point. So you can fix a bad take or add a solo over an existing section without re-recording anything else. Overdubs and punch-ins are fully round-trip latency compensated, so the part you add lands where you played it against the tape, and punching out is instant.