Digital Audio Tape

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Digital Audio Tape
Magnetic cassette tape
EncodingLossless real-time
CapacityUp to 120 or 180 minutes (consumer tapes on non-LP mode)
Read mechanismRotating head, helical scan
Write mechanismRotating head, helical scan
Developed bySony
UsageAudio storage
Extended toDigital Data Storage
Released1987; 37 years ago (1987)

Digital Audio Tape (DAT or R-DAT) is a signal recording and playback medium developed by

sampling rate respectively) at 16 bits quantization. If a comparable digital source is copied without returning to the analogue domain, then the DAT will produce an exact clone, unlike other digital media such as Digital Compact Cassette or non-Hi-MD
MiniDisc, both of which use a lossy data-reduction system.

Like most formats of

compact audio cassette
, although many DAT recorders had the capability to record program numbers and IDs, which can be used to select an individual track like on a CD player.

Although intended as a replacement for analog audio compact cassettes, the format was never widely adopted by consumers because of its expense, as well as concerns from the music industry about unauthorized high-quality copies. The format saw moderate success in professional markets and as a computer storage medium, which was developed into the Digital Data Storage format. As Sony has ceased production of new recorders, it will become more difficult to play archived recordings in this format unless they are copied to other formats or hard drives. Meanwhile, the phenomenon of sticky-shed syndrome has been noted by some engineers involved in re-mastering archival recordings on DAT, which presents a further threat to audio held exclusively in this medium.

History

Development

The technology of DAT is closely based on

Compact Cassette format but was difficult to develop a fixed recording head for high-density recording while the rotating head of the R-DAT had a proven track record in VCR formats like VHS & Betamax. While R-DAT would later be known as just "DAT", there would be an S-DAT media format that would be released later in the form of the Digital Compact Cassette. Sony would later introduce another R-DAT format in the form of NT which was meant to replace the Microcassette and Mini-Cassette.[citation needed
]

The DAT standard allows for four sampling modes: 32 kHz at 12 bits, and 32 kHz, 44.1 kHz or 48 kHz at 16 bits. Certain recorders operate outside the specification, allowing recording at 96 kHz and 24 bits (HHS). Some early machines aimed at the consumer market did not operate at 44.1 kHz when recording so they could not be used to 'clone' a compact disc. Since each recording standard uses the same tape, the quality of the sampling has a direct relation to the duration of the recording – 32 kHz at 12 bits will allow six hours of recording onto a three-hour tape while HHS will only give 90 minutes from the same tape. Included in the signal data are subcodes to indicate the start and end of tracks or to skip a section entirely; this allows for indexing and fast seeking. Two-channel

sampling rates and bit depths, but the R-DAT standard does support 4-channel recording at 32 kHz.[citation needed
]

DATs are between 15 and 180 minutes in length, a 120-minute tape being 60 metres in length. DATs longer than 60 metres tend to be problematic in DAT recorders due to the thinner media. DAT machines running at 48 kHz and 44.1 kHz sample rates transport the tape at 8.15 mm/s. DAT machines running at 32 kHz sample rate transport the tape at 4.075 mm/s.[citation needed]

Predecessor formats

DAT was not the first digital audio tape;

consumer product. Denon's development dated from its work with Japan's NHK Broadcasting; NHK developed the first high-fidelity PCM audio recorder in the late 1960s. Denon continued development of their PCM recorders that used professional video machines as the storage medium, eventually building 8-track units used for, among other productions, a series of jazz records made in New York in the late 1970s.[citation needed
]

In 1976, another digital audio tape format was developed by

Telarc Records of Cleveland, Ohio. Telarc's April, 1978 recording of the Holst Suites for Band by Frederick Fennell and the Cleveland Wind Ensemble was a landmark release, and ushered in digital recording for America's classical music labels. Soundstream's system was also used by RCA.[citation needed
]

Starting in 1978,

Minneapolis, Minnesota. This system was used in June 1978 to record Aaron Copland's "Appalachian Spring" by the St. Paul Chamber Orchestra conducted by Dennis Russell Davies. That record was the first Grammy-winning digital recording. The production version of the 3M Digital Mastering System was used in 1979 to record the first all-digital rock album, Ry Cooder's "Bop Till You Drop," made at Warner Brothers Studio in California.[citation needed
]

The first consumer-oriented PCM format used consumer video tape formats (Beta and VHS) as the storage medium. These systems used the EIAJ digital format, which sampled at 44.056 kHz at 14 bits. The Sony PCM-F1 system debuted in 1981, and Sony from the start offered the option of 16-bit wordlength. Other systems were marketed by Akai, JVC, Nakamichi and others. Panasonic, via its Technics division, briefly sold a digital recorder that combined an EIAJ digital adapter with a VHS video transport, the SV-P100. These machines were marketed by consumer electronics companies to consumers, but they were very pricey compared to cassette or even reel-to-reel decks of the time. They did catch on with the more budget conscious professional recordists, and some boutique-label professional releases were recorded using these machines.[2]

Starting in the early 1980s, professional systems using a PCM adaptor were also common as mastering formats. These systems digitized an analog audio signal and then encoded the resulting digital stream into an analog video signal so that a conventional VCR could be used as a storage medium.[citation needed]

One of the most significant examples of a PCM adaptor-based system was the

U-Matic-format VCR for its transport, connected to external digital audio processing hardware. It (and its later versions such as the PCM-1610 and 1630) was widely used for the production and mastering of some of the first Digital Audio CDs in the early 1980s. Once CDs were commercially introduced in 1982, tapes recorded on the PCM-1600 were sent to the CD pressing plants to be used to make the glass master disc for CD replication.[citation needed
]

Other examples include

mastering format that used a very unusual sampling rate of 50.4 kHz.[citation needed
]

For high-quality studio recording, all of these formats were effectively made obsolete in the early 1980s by two competing

reel-to-reel formats with stationary heads: Sony's DASH format and Mitsubishi's continuation of the X-80 recorder, which was improved upon to become the ProDigi format. (In fact, one of the first ProDigi-format recorders, the Mitsubishi X-86C, was playback-compatible with tapes recorded on an X-80.) Both of these formats remained popular as an analog alternative until the early 1990s, when hard disk recorders rendered them obsolete.[citation needed
]

Demise

Sony released its last DAT product with the DAT Walkman TCD-D100 in 1995 and continued to produce it until November 2005 when Sony announced that its remaining DAT machine models would be discontinued the following month.

hard disk recording or memory card equipment, which offers much more flexibility and storage, Digital Data Storage tapes, which are broadly similar to DATs, apart from tape length and thickness on some variants, and are still manufactured today unlike DAT cassettes, are often used as substitutes in many situations.[citation needed
]

Digital Compact Cassette

The DAT recorder mechanism was considerably more complex and expensive than an analogue

Minidisc format (which has random access and editing features), it was not successful with consumers either. However, DCC proved that high quality digital recording could be achieved with a cheap simple mechanism using stationary heads.[citation needed
]

Anti-DAT lobbying

Aiwa HD-S1 portable DAT recorder from 1990 with DAT tape for size comparison. It is 146 mm high and 95 mm wide, the thickness is 38 mm.[5]

In the late 1980s, the

notch filter,[6] meaning that copyrighted prerecorded music, whether analog or digital, whether on LP, cassette, or DAT, would have distorted sound resulting from the notch filter applied by the publisher at the time of mastering for mass reproduction. A National Bureau of Standards study showed that not only were the effects plainly audible, but that it was not even effective at preventing copying.[citation needed
]

This opposition by CBS softened after Sony, a DAT manufacturer, bought CBS Records in January 1988. By June 1989, an agreement was reached, and the only concession the RIAA would receive was a more practical recommendation from manufacturers to Congress that legislation be enacted to require that recorders have a

filesharing systems such as Napster.[8]

Uses

Professional recording industry

DAT was used professionally in the 1990s by the audio recording industry as part of an emerging all-digital production chain also including digital multi-track recorders and

]

Pre-recorded albums

DAT Recorder (Kenwood DX-7030)
DAT was also used in professional environ­ments like recording studios and broadcasting institutions. The depicted device is a professional Sony PCM-7030 DAT recorder which had a recommended retail price of 8000 US dollars.[9]

In December 1987, The Guitar And Other Machines by the British post-punk band The Durutti Column, became the first commercial release on DAT. Later in May 1988, Wire released their album The Ideal Copy on the format.[10] Several other albums from multiple record labels were also released as pre-recorded DATs in the first few years of the format's existence, in small quantities as well. Factory Records released a small number of albums on the format, including New Order's best-selling compilation Substance 1987, but many planned releases were cancelled.[11]

Amateur and home use

Sony DAT Walkman TCD-D7

DAT was envisaged by proponents as the successor format to analogue audio cassettes in the way that the compact disc was the successor to vinyl-based recordings. It sold well in Japan, where high-end consumer audio stores stocked DAT recorders and tapes into the 2010s and second-hand stores generally continued to offer a wide selection of mint condition machines. However, there and in other nations, the technology was never as commercially popular as CD or cassette. DAT recorders proved to be comparatively expensive and few commercial recordings were available. Globally, DAT remained popular, for a time, for

jam bands, such as the Grateful Dead and Phish, recorded and stored high-quality audience recordings of live concerts on the format.[12]

Computer data storage medium

The format was designed for audio use, but through the ISO Digital Data Storage standard was adopted for general data storage, storing from 1.3 to 80 GB on a 60 to 180 meter tape depending on the standard and compression. It is a sequential-access medium and is commonly used for backups. Due to the higher requirements for capacity and integrity in data backups, a computer-grade DAT was introduced, called DDS (Digital Data Storage). Although functionally similar to audio DATs, only a few DDS and DAT drives (in particular, those manufactured by Archive for SGI workstations)[13] are capable of reading the audio data from a DAT cassette. SGI DDS4 drives no longer have audio support; SGI removed the feature due to "lack of demand".[14]

See also

References

  1. ^ "Sony History". Sony.net. Archived from the original on 25 June 2010. Retrieved 19 September 2009.
  2. ^ "1981 Sony PCM-F1 Digital Recording Processor-Mix Inducts Sony PCMF1 Processor into 2007 TECnology Hall of Fame". Archived from the original on 14 March 2011. Retrieved 23 March 2011.
  3. ^ G. Mancini (March 2004). "The Decca Digital Audio Recording System". Archived from the original on 26 October 2007. Retrieved 25 October 2007.
  4. ^ "Sony Drops DAT". Anime News Service. 15 November 2005. Archived from the original on 27 May 2008. Retrieved 29 August 2006.
  5. ^ Technical data of Aiwa HD-S1, from datrecorders.co.uk, retrieved on 27 January 2023
  6. ^ Holt, J. Gordon; Gold, Alvin (1987). "Copycode: Diminishing DAT". Stereophile. Retrieved 12 June 2012.
  7. ^ Goldberg, Michael (21 September 1989). "Labels Back Down on DAT". Rolling Stone. No. 561. p. 26.
  8. ^ Knopper, Steve (2009). Appetite for Self-Destruction. Simon and Schuster: Free Press. pp. 78–9.
  9. ^ Data on Sony PCM-7030 at datrecorders.co.uk
  10. ^ Media, Spin L. L. C. (December 1988). "Back in the Days of '88". Spin. 4 (9): 71. Retrieved 29 April 2011.
  11. ^ "DAT and Copycode (Q Magazine article c.1988) – Factory Records". cerysmaticfactory.info.
  12. ^ Lei, Richard (16 October 1994). "The Hottest Band the World Has Never Heard". The Washington Post. Retrieved 26 November 2019.
  13. ^ "Can you Rip DAT audio? (Ask Slashdot forum thread)". Slashdot. 1 October 1999. Retrieved 25 October 2007.
  14. ^ "DAT/DDS hardware". 26 March 2003. Archived from the original on 16 October 2007. Retrieved 25 October 2007.

External links