A SYNTH
RECORDER
FOR iPHONE.

Straight over USB

A growing number of synths send audio over their USB port as a class-compliant device, the same way an audio interface does. If yours does, one cable from the synth to the iPhone is the whole setup. iOS presents the synth to REK. as an ordinary input, with no drivers. Check the manual for “class-compliant USB audio”, or for a line saying it works with iPhone or iPad.

Through an interface

Most synths only send audio out of their jacks. Run the line or headphone output into any class-compliant USB-C audio interface, and plug the interface into the phone. REK. records the interface like any other input, and everything else on this page applies. The USB audio guide covers interfaces, cables and power.

Why a recorder, not a DAW

Synth playing is mostly exploring: turning things until something happens. A synth recorder has to keep up with that. Stopping to open a laptop, start a project and arm a track is how that moment gets lost. REK. puts record on the first screen. Press the red one before you start turning knobs, and every pass becomes its own take, named for when it happened. Nothing is overwritten, so the good one is never under the next one.

Resonance, without the fear

A resonant filter sweep is the classic way to clip a recording. The record path in REK. is 32-bit float, so a peak that would have flattened a fixed-point file has no ceiling to hit on the way into the phone. GAIN moves what you hear by ±12 dB and leaves the file alone, and the PK lamp latches so you know a peak happened. Distortion the synth or the interface preamp makes before the cable is the one thing float cannot undo.

Mono synths

REK. records mono or stereo, depending on the route. A mono synth into one input of an interface shows a single M row on the meter, and the take is what you played.

Sequenced parts

The metronome can count you in for one or two bars, anywhere from 40 to 240 BPM, so you can start a sequence on the one. Set it to OFF when you are drifting.

Long improvisations

The free version records one minute per take, which is enough to prove the setup works. One payment of $9.99 lifts the limit for good. Takes stream from disk, so an hour-long drone plays back as easily as a minute, and low storage warns rather than refuses.