An Introduction to Digital Audio Tape - DAT
DAT was a format which failed in the consumer market but found some popularity with professionals during the 90s and the first years of the new century. There are many archived recordings that still need to be transferred to other formats before DAT decks become scarce.
DAT - What is it?
Digital Audio Tape (DAT) was an audio recording and playback medium developed by Sony - introduced in 1987 - and was intended to be the successor to the audio cassette. It is somewhat similar in appearance but at 73 mm × 54 mm × 10.5 mm it is roughly half the size; its height being comparable to an triple-A battery stood on end. DAT was a digital technology with superior maximum quality as compared to a commercial CD and was capable of making perfect digital clones from a digital source unlike other standards of the day (Digital Compact Cassette and MiniDisc) that used lossy compression.
DAT - The Technology
Very similar to video recording technology of the day,
DAT used a rotating head with a helical scan to record data. The method of data storage actually worked as a security measure of sorts and prevented splicing tapes to edit them which was possible on analog tapes, digital compact cassettes, and open reel digital tapes.
The DAT standard specified four sampling modes: 32 kHz at 12 bits, and 32 kHz, 44.1 kHz or 48 kHz at 16 bits. It was possible to find non-standard recorders that allowed recording at 96 kHz and 24 bits (HHS). DAT was unable to record long durations at the highest sample rates. The same tape at one rate could record for 6 hours and at another rate a mere 90 minutes. Only so much tape can be packed into a DAT shell.
With the more complicated rotary head the recorder mechanism was significantly more expensive for a DAT recorder than for its stationary analog counterpart. Because of this Philips and Panasonic created the Digital Compact Cassette (DCC) a less impressive but certainly enviable stationary head design that had decent quality at a reduced cost. It was no match for the DAT because of its required lossy compression but overall it did a good job and proved a static head could be used for high quality digital recordings.
DAT - Was There Ever a Need?
Despite the RIAA's lawsuits and lobbying against DAT manufacturers it eventually gained quite a following in the 1990's in the recording industry. Back in the 1990's a great many archival tapes were made using the DAT media. These archives are still available today in some places but the machines are no longer produced so unless these archives are transferred to another format it will become harder and harder with time to find archivists and audio transfer companies capable of transferring the media to a current format.
Because of DATs lossless encoding and high quality it induced no hiss or other electronic noise so became a favorite for creating perfect master copies. It is actually possible with enough digital equipment to create a complete digital chain between the microphone and the speakers on the CD player. With digital mixers and other digital hardware, analog induced problems could be completely eradicated from the majority of the process.
DAT In The Home
DAT, for many reasons, never gained a great deal of popularity with the general consumer. For the most part it was easier and less expensive to go with the alternatives. It was popular with some garage bands and boutique studios but the everyday Joe rarely saw one until their brief stint as sequential data back-up devices. Data backup tapes enjoyed a few years in the sun before being replaced by large and then ultra large external drives using the serial, parallel and later, USB ports.
