Recording with OP-1 Field and iPhone
The Teenage Engineering OP-1 Field is a portable synthesizer, sampler and 4-track tape recorder. Pair it with Reel on your iPhone and you can capture all 4 of its tracks separately over USB. Then you mix and overdub them in the app.
What you need
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.
Setting OP-1 Field to 8ch USB mode
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).
Connecting to Reel
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.
Recording all 4 OP-1 tracks at once
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, overdub, add effects and export each one separately.
Using the original OP-1 (not Field)
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.
Adding overdubs 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.
Frequently Asked Questions
Can I record the OP-1 Field into my iPhone?
Yes. Connect the OP-1 Field to your iPhone with a USB-C cable and open Reel. The app detects it automatically as a USB audio device.
How do I record all 4 OP-1 Field tracks separately?
Set the OP-1 Field USB MODE to 8ch in System settings. That exposes each of the 4 tracks as a separate channel pair. Route each one to its own track in Reel and arm all 4 for recording.
Does the original OP-1 support multi-track recording over USB?
No. The original OP-1 only sends 2 channels over USB. To capture all 4 tracks into Reel you record one track at a time. Mute the others on the OP-1 and arm the matching track in Reel.
What cable do I need to connect the OP-1 Field to an iPhone?
For USB-C iPhones you need a USB-C to USB-C cable. For Lightning iPhones you need the Apple Lightning to USB 3 Camera Adapter plus a USB-C cable.
Can I overdub on top of OP-1 Field recordings in Reel?
Yes. Once your OP-1 Field tracks are in Reel you can overdub vocals, instruments or extra OP-1 parts. Put them on the same tracks or on new ones.
More from the blog
How to Record Your OP-XY (and Why You Cannot Get Stems Over USB)
The OP-XY sends a stereo master, not stems. Why that myth exists, the exact levels and settings that matter, and the multi-out trick that gets you two submixes at once.
The Best Recorder for the OP-1 Field (2026)
Which recorder should you pair with an OP-1 Field? An honest look at the TP-7, handheld recorders and iPhone multitrack, and the one thing most recommendations miss.
Author
Tug
Founder of 24bit Studio and the developer of Reel, a portable 4-track recorder for iPhone.