Transferring DAT Tapes

One of the earliest miracles of the digital revolution, DAT (which is simply an acronym for “digital audio tape”) was a superior and convenient format, embraced by professional and consumer alike. Working much like a tiny VHS cartridge, the thin, narrow magnetic tape used the rotating head, helical scan model, and provided pristine digital sound. Despite its success, by the early 2000’s DAT had already become mostly obsolete, as non-linear, computer-stored sound files took over. Eventually DAT decks were no longer manufactured, and their repair and maintenance became less obtainable and more expensive. Heads wear out, belts and rollers turn to goo, boards get fried, gears seize up, etc. Additionally, though the tapes themselves are digital and less susceptible to print-through and other hazards common to analog tape, they are still magnetic tapes—with a questionable shelf-life.

Skip forward to today. Now many people with collections of DAT tapes are finding that their decks no longer work, and they have no way of playing back their precious material. That’s where Commodore can help. We keep on hand a supply of working/rebuilt DAT machines, and are capable of converting small or large collections to more versatile non-linear formats such as WAV and FLAC, allowing playback for the future on many types of devices.

Since it is a tape format, each tape must be played through in real time for the data to be copied. DAT tapes can be over 3 hours long, so this is not a quick procedure, but ideally, the digital data simply passes from one device to another and the transfer is done. However, there are a few transfer caveats that are particular to DAT, which can complicate the process.

With one recent project involving 1200 tapes of live concerts spanning 25 years, we experienced hundreds of tapes with multiple shows that had more than one sample rate (48, 44.1, 32 kHz) on a given tape. This makes it impossible to copy the data “in the background” since the WAV or FLAC file must be set to a single rate, and the change creates awful-sounding garbled audio on the mismatched portions. There are two ways around this; one would be to babysit each and every tape as it plays, keeping an eye out for changes, and stopping to create a new file at the new rate before proceeding. With 1200 tapes, this would have obviously been prohibitively expensive. The second way (and the preferred solution) is to make a simultaneous analog-to-digital transfer of the audio through the DAT deck’s analog outputs, which will ignore changes in sample rate and simply provide pristine audio. If the digital error flag appears during a transfer, the analog-to-digital version can be used in place of the corrupted digital-to-digital one, and honestly, I think most listeners would be hard-pressed to hear the difference.

It should be noted that the maximum approved length for an audio DAT is 120 minutes. There are tapes that run 180 and even 240 minutes, but they are made to back up computer data, not to play real-time audio, and they are prone to errors and dropouts. Some higher-end studio decks will not even accept these thinner tapes. This is not to say that they can’t be played, but if data tapes were used for audio, the results can be unpredictable. Always check your tapes. If they do not say DAT (which specifies them as suitable for audio) then they will be labeled differently as well. A common misconception is that the 60m and 90m designations on non-DAT tapes refer to the number of minutes of recording time. That is wrong. It refers to the physical length of the tape: 60 meters is roughly equivalent to a 120-minute DAT, and 90 meters, though it will give 180 minutes of recording time, may do so with questionable results. Nevertheless, most of the time we have been able to successfully work even with 90-meter tapes.

So whether it’s a single tape or a large collection, we have innovative ways to handle the job and keep it affordable for the client.