Insert an SD card of choice into the Zoom F1 and turn it on. It wil ask to format the card. Do so.

Copy music, recordings, audiobooks, podcasts, and whatever else you want to play. Only MP3 has been tested so far, but WAV files can be created on the device, so WAV playback should be possible as well. Convert as needed.

The Zoom F1 creates files with the following naming convention: ZOOM0001.MP3.

Bulk rename files as such using a bulk rename utility of choice. The device will not recognize files that do not follow this naming convention.

Once powered on with an SD card full of properly named audio files, press the Play button to start playing audio. It will start payback at ZOOM001.MP3 and go in order, starting over once it finishes the last file.