What Happens if Power is Lost During Recording?

Reliable, rock-solid recording is the single most important design criteria of Sound Devices recorders. 7-Series recorders are built upon a highly-stable, dedicated hardware and firmware foundation. Recording integrity is further enhanced through a process of periodic, automatic file directory and header updates written to disk during recording. This ensures file integrity in the unlikely event of a total loss of power.

FAT32 File System

Digital recorders of all types, including hard drive, CompactFlash, DVD-RAM, etc., read, write, and organize files using a file system. Storage volumes are formatted according to a particular disk formatting system. Nearly all portable digital audio recorders, including Sound Devices recorders, and digital cameras use FAT32 disk formatting. FAT32 is directly supported by a vast array of hardware and computer environments including Mac OS, Windows, and Linux computers with no need to convert, copy, or mirror from other disk formats. When connected to a computer workstation over FireWire or USB, a 7-series recorder’s drive appears as a FAT32 mass storage device and can be used to copy, play, transfer, or edit its WAV files.

The 7-series FAT32 disk format contains a directory (plus two redundant directories available should the primary directory become corrupted) which points to the addresses of all the files on the disk. It is important that this data (database) is correct and up-to-date so that all files are accessible. A WAV file’s header describes attributes necessary for proper playback; it is crucial to save and update this information regularly.

Periodic Refresh of Header Data

7-series recorders automatically update the FAT32 directory and file headers during recording. In the event of an unexpected power loss during recording, the audio file remains intact and accessible. This periodic updating has always been designed into the 788T and is available in the current revisions of firmware for 702, 702T, 722, and 744T.

Special Note: While 7-series recorders prevent audio loss in event of sudden power failure, it is easy to prevent power failure. Keep a charged Li-Ion battery attached to the recorder all times. If power is lost when operated on external DC, the recorder automatically switches to the attached Li-Ion battery. Depleted Li-Ion batteries can similarly be exchanged during recording by attaching external DC power, then replacing the Li-Ion battery with a fully charged cell. The recorder will continue to operate uninterrupted.