By Tug·July 4, 2026·6 min read

How to Record a Synth into Your iPhone

Recording a hardware synth into an iPhone comes down to one question: does your synth have its own USB audio, or only line outputs? If it does USB audio, it plugs into the phone with a single cable. If it only has line outs, which most synths do, you run those into a class-compliant interface. Here is both routes and the levels to watch.

USB, or line out to an interface

If your synth streams class-compliant USB audio, connect it straight to the phone with one cable. If it only has analog line outputs, run those into a class-compliant audio interface, and the interface into the phone.

Most classic and analog synths are the second case, line outputs and no USB audio, so an interface is the usual answer. Check your synth's manual to know which you have.

Does your synth have USB audio?

Some modern synths and grooveboxes do their own class-compliant USB audio, so they act as their own interface into the phone. Many do not, especially analog and older instruments, which only have quarter-inch line outputs.

The manual will say whether it can send audio over USB. If it can, that is the simplest route. If not, you use its outputs.

The line-out route (most synths)

Run the synth's main outputs, usually quarter-inch jacks, into the line inputs of a class-compliant interface, then connect the interface to the phone. Set the interface inputs to line level, not instrument or mic. If the synth has left and right outputs, record both to keep it in stereo.

This is the standard way to record any synth that does not do USB audio, and it works with any class-compliant interface.

The USB route (some synths)

If your synth does class-compliant USB audio, connect it to the phone directly, with a USB-C cable on a USB-C iPhone or an Apple camera adapter on a Lightning iPhone. Set any USB audio mode the synth needs first, then record.

This is the tidiest setup when your instrument supports it, since there is no interface in the chain at all.

Watch the levels, and where Reel fits

Synths can put out a hot signal, so set the interface to line level, keep an eye on the meters, and pull the synth's volume down if it is clipping. Recording in 32-bit float gives you headroom either way.

Reel records the synth from either route in clean 32-bit float, and lets you layer patches across its four tracks, so you can build a whole part from one synth. A stereo synth arrives as one pair and Reel arms all four tracks to it by default, so a wide pad keeps its width with nothing to set up. Set a record length in bars and each patch ends itself on the bar and loops, which is the quick way to stack a pad, a bass and an arp from one machine. If the synth runs hot, long-press a fader to set that track's input gain in the app, and every strip has its own meter. With both hands on the keys, arm the take and let the first note start it.

See how Reel works

Watch a take come together in Reel.

Frequently Asked Questions

Can you record a synth into an iPhone?

Yes. If the synth does class-compliant USB audio it connects with one cable. If it only has line outputs, run those into a class-compliant audio interface and the interface into the phone, and record in an app like Reel.

Do synths have USB audio?

Some modern synths and grooveboxes do class-compliant USB audio and act as their own interface. Many, especially analog and older synths, only have quarter-inch line outputs and need an interface. Check your synth's manual.

How do I connect a synth to my iPhone?

For a synth with USB audio, a single USB cable, or a camera adapter on a Lightning iPhone. For a synth with only line outputs, its outputs into a class-compliant interface set to line level, then the interface into the phone.

Can I record a synth without an interface?

Only if the synth does its own class-compliant USB audio, in which case it connects directly. A synth with just analog line outputs needs a class-compliant interface to get its sound into the phone cleanly.