Editing Digital Audio Tape

{{about-distinguish-text|the specific format named Digital Audio Tape|tape-based digital audio formats in general, including [[Digital Compact Cassette]] or any of several [[Reel-to-reel#Digital reel-to-reel|digital reel-to-reel]] formats}}
{{short description|Digital audio cassette format developed by Sony}}

{{Multiple issues|
{{original research|date=September 2010}}
{{more citations needed|date=September 2010}}
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{{Use dmy dates|date=July 2020}}
{{Infobox storage medium
| name        = Digital Audio Tape
| logo        = Digital Audio Tape (logo).svg{{!}}class=skin-invert
| image       = Dat cartridge.jpg
| caption     = A 90-minute DAT cartridge, with a [[AAA battery]] (LR03) for size comparison
| type        = [[Magnetic cassette tape]]
| encoding    = Lossless real-time
| capacity    = Up to 120 or 180 minutes (consumer tapes on non-LP mode)
| read        = Rotating head, helical scan 
| write       = Rotating head, helical scan
| standard    =
| owner       = [[Sony]]
| use         = Audio storage
| extended to = [[Digital Data Storage]]
| released    = {{Start date and age|1987}}
}}

'''Digital Audio Tape''' ('''DAT''' or '''R-DAT''') is a signal recording and playback medium developed by [[Sony]] and introduced in 1987.<ref>{{cite web|url=http://www.sony.net/Fun/SH/1-21/h5.html|title=Sony History|website=Sony.net|access-date=19 September 2009|archive-url=https://web.archive.org/web/20100625232554/http://www.sony.net/Fun/SH/1-21/h5.html|archive-date=25 June 2010|url-status=dead}}</ref> In appearance it is similar to a [[Compact Cassette]], using 3.81&nbsp;mm / 0.15" (commonly referred to as 4&nbsp;mm) [[magnetic tape]] enclosed in a protective shell, but is roughly half the size at 73&nbsp;mm × 54&nbsp;mm × 10.5&nbsp;mm. The recording is [[Digital data|digital]] rather than [[analog signal|analog]]. DAT can record at sampling rates equal to, as well as higher and lower than a [[CD]] (44.1, 48, or 32 [[kHz]] [[sampling rate]] respectively) at 16 [[bit]]s [[Quantization (signal processing)|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-[[MiniDisc#Hi-MD|Hi-MD]] MiniDisc, both of which use a lossy data-reduction system.

Like most formats of [[videocassette]], a DAT cassette may only be recorded and played in one direction, unlike an analog [[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 ===
{{multiple image
| direction         = vertical
| total_width       = 
| perrow            =
| header            =
| image1            = DAT & Compact Cassette (cropped).jpg
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| image2            = DAT & Compact Cassette vert (cropped).jpg
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| footer            = DAT compared to Compact Cassette
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The technology of DAT is closely based on [[video tape recorder|video recorders]], using a rotating head and [[helical scan]] to record data. This prevents DATs from being physically [[edited]] in the cut-and-splice manner of [[analog tape]]s, or open-reel digital tapes like [[ProDigi]] or [[Digital Audio Stationary Head|DASH]]. In 1983, a DAT meeting was established to unify the standards for recording digital audio on magnetic tape developed by each company and in 1985, two standards were created: '''R-DAT''' ('''Rotating Digital Audio Tape''') using a rotary head and '''S-DAT''' ('''Stationary Digital Audio Tape''') using a fixed head. The S-DAT format had a simple mechanism similar to the [[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]]. As the S-DAT version was never released, R-DAT had been renamed as simply "DAT" by the time of its launch. However, Philips and Matsushita (Panasonic) would later release their own stationary head digital format in the form of the [[Digital Compact Cassette]]. Sony would later introduce another rotating head format in the form of [[NT (cassette)|NT]] which was intended to replace the [[Microcassette]] and [[Mini-Cassette]].{{fact|date=July 2022}}

The DAT standard allows for four sampling modes: 32&nbsp;kHz at 12 bits, and 32&nbsp;kHz, 44.1&nbsp;kHz or 48&nbsp;kHz at 16 bits. Certain recorders operate outside the specification, allowing recording at 96&nbsp;kHz and 24 bits (HHS). Some early machines aimed at the consumer market did not operate at 44.1&nbsp;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&nbsp;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 [[stereo]] recording is supported under all [[sampling rate]]s and bit depths, but the R-DAT standard does support 4-channel recording at 32&nbsp;kHz.{{fact|date=July 2022}}

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&nbsp;kHz and 44.1&nbsp;kHz sample rates transport the tape at 8.15&nbsp;mm/s. DAT machines running at 32&nbsp;kHz sample rate transport the tape at 4.075&nbsp;mm/s.{{fact|date=July 2022}}

=== Predecessor formats ===
DAT was not the first digital audio tape; [[pulse-code modulation]] (PCM) was used in [[Japan]] by [[Denon]] in 1972 for the mastering and production of analogue [[phonograph record]]s, using a [[Quadruplex videotape|2-inch Quadruplex]]-format videotape recorder for its [[transport (recording)|transport]], but this was not developed into a [[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.{{fact|date=July 2022}}

In 1976, another digital audio tape format was developed by [[Soundstream]], using {{convert|1|in|mm|1|spell=in}} wide [[reel-to-reel tape]] loaded on an [[instrumentation]] recorder manufactured by [[Honeywell]] acting as a transport, which in turn was connected to outboard digital audio encoding and decoding hardware of Soundstream's own design. Soundstream's format was improved through several prototypes and when it was developed to 50&nbsp;kHz sampling rate at 16 bits, it was deemed good enough for professional classical recording by the company's first client, [[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]].{{fact|date=July 2022}}

Starting in 1978, [[3M]] introduced its own line and format of digital audio tape recorders for use in a [[recording studio]]. One of the first prototypes of 3M's system was installed in the studios of [[Sound 80]] in [[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|Ry Cooder's]] "Bop Till You Drop," made at Warner Brothers Studio in California.{{fact|date=July 2022}}

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&nbsp;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.<ref>{{cite web |url=http://mixonline.com/TECnology-Hall-of-Fame/1981-sony-pcmf1/ |title=1981 Sony PCM-F1 Digital Recording Processor-Mix Inducts Sony PCMF1 Processor into 2007 TECnology Hall of Fame |access-date=2011-03-23 |url-status=dead |archive-url=https://web.archive.org/web/20110314050116/http://mixonline.com/TECnology-Hall-of-Fame/1981-sony-pcmf1/ |archive-date=14 March 2011}}</ref>

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.{{fact|date=July 2022}}

One of the most significant examples of a PCM adaptor-based system was the [[Sony PCM-1600]] digital audio mastering system, introduced in 1978. The PCM-1600 used a [[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.{{fact|date=July 2022}}

Other examples include [[dbx, Inc.]]'s [[Dbx Model 700 Digital Audio Processor|Model 700]] system, which, similar to later [[Super Audio CD]]s, used a high sample-rate delta-sigma modulation rather than PCM; Decca's 1970s [[PCM]] system,<ref>{{cite web |url=http://www.mancini99.freeserve.co.uk/Decca_1.html |title=The Decca Digital Audio Recording System |author=G. Mancini |date=March 2004 |access-date=25 October 2007 |url-status=dead |archive-url=https://web.archive.org/web/20071026152024/http://www.mancini99.freeserve.co.uk/Decca_1.html |archive-date=26 October 2007}}</ref> which used a videotape recorder manufactured by [[IVC (videotape recorder)|IVC]] for a transport; and [[Mitsubishi]]'s X-80 digital recorder, a 6.4&nbsp;mm ({{frac|1|4}}&nbsp;in) [[open reel]] digital [[Audio mastering|mastering]] format that used a very unusual sampling rate of 50.4&nbsp;kHz.{{fact|date=July 2022}}

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 [[Digital Audio Stationary Head|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.{{fact|date=July 2022}}

=== 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.<ref>{{cite web|title=Sony Drops DAT|url=http://www.animenewsservice.com/archives/nov30.htm|publisher=Anime News Service|date=15 November 2005|access-date=29 August 2006|archive-date=27 May 2008|archive-url=https://web.archive.org/web/20080527091928/http://www.animenewsservice.com/archives/nov30.htm|url-status=dead}}</ref> Sony had sold around 660,000 DAT products since its introduction in 1987.{{Citation needed|date=September 2010}} Sony continued to produce blank DAT tapes until 2015 when it announced it would cease production by the end of the year. Even with this, the DAT format still finds regular use in [[film]] and [[television]] recording,{{Citation needed|date=September 2010}} primarily due to the support in some recorders for [[SMPTE time code]] synchronisation, and sometimes by audio enthusiasts as a way of backing up vinyl, compact cassette and CD collections to a digital format to then be transferred to PC. Although it has been superseded by modern [[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.{{fact|date=July 2022}}

=== Digital Compact Cassette ===
The DAT recorder mechanism was considerably more complex and expensive than an analogue [[cassette deck]] mechanism due to the rotary helical scan head, therefore [[Philips]] and [[Panasonic Corporation]] developed a rival [[Digital data|digital]] [[tape recorder]] system with a stationary head based on the [[analog recording|analogue]] [[compact cassette]] known as S-DAT. The [[Digital Compact Cassette]] (DCC) was cheaper and simpler mechanically than DAT, but did not make perfect digital copies as it used a [[lossy compression]] technique called [[MPEG-1 Audio Layer I|PASC]]. (Lossy compression was necessary to reduce the data rate to a level that the DCC head could record successfully at the linear tape speed of 4.75&nbsp;cm/s that the compact cassette system uses.) DCC was never a competitor to DAT in recording studios, because DAT was already established, and studios favor lossless formats.  As DCC was launched at the same time as [[Sony]]'s [[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.{{fact|date=July 2022}}

== Anti-DAT lobbying ==
{{See also|Audio Home Recording Act#History and legislative background}}
[[File:Aiwa DAT recorder and Sony DAT tape (edited).jpg|thumb|upright=1.25|[[Aiwa]] HD-S1 portable DAT recorder from 1990 with DAT tape for size comparison. It is 146&nbsp;mm high and 95&nbsp;mm wide, the thickness is 38&nbsp;mm.<ref>[http://www.datrecorders.co.uk/hds1.php Technical data of Aiwa HD-S1], from datrecorders.co.uk, retrieved on 27 January 2023</ref>]]
In the late 1980s, the [[Recording Industry Association of America]] (RIAA) unsuccessfully lobbied against the introduction of DAT devices into the U.S. Initially, the organization threatened legal action against any manufacturer attempting to sell DAT machines in the country. It later sought to impose restrictions on DAT recorders to prevent them from being used to copy LPs, CDs, and prerecorded cassettes. One of these efforts, the [[Digital Audio Recorder Copycode Act of 1987]] (introduced by [[Al Gore|Sen. Al Gore]] and [[Henry Waxman|Rep. Waxman]]), initiated by CBS Records president [[Walter Yetnikoff]], involved a technology called [[CopyCode]] and required DAT machines to include a chip to detect attempts to copy material recorded with a [[notch filter]],<ref>{{cite journal |last1= Holt|first1= J. Gordon|last2= Gold|first2= Alvin|year= 1987|title= Copycode: Diminishing DAT|journal= Stereophile|url= http://www.stereophile.com/asweseeit/copycode_diminishing_dat/index.html|access-date= 12 June 2012}}</ref> 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.{{fact|date=July 2022}}

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 [[Serial Copy Management System]] to prevent digital copying for more than a single generation.<ref><!--this reference applies to the entire paragraph up to this point-->{{cite magazine|last=Goldberg|first=Michael|date=21 September 1989|title=Labels Back Down on DAT|magazine=Rolling Stone|issue=561|page=26}}</ref> This requirement was enacted as part of the [[Audio Home Recording Act]] of 1992, which also imposed [[Private copying levy|taxes]] on DAT recorders and blank media. However, the [[computer industry]] successfully lobbied to have [[personal computers]] exempted from that act, setting the stage for massive consumer copying of copyrighted material on materials like [[CD-R|recordable CDs]] and by extension, [[filesharing]] systems such as [[Napster]].<ref>{{cite book|last=Knopper|first=Steve|title=Appetite for Self-Destruction|url=https://archive.org/details/appetiteforselfd00knop_0|url-access=registration|year=2009|publisher=Simon and Schuster: Free Press|pages=[https://archive.org/details/appetiteforselfd00knop_0/page/78 78–9]}}</ref>

== 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 [[digital mixing console]]s that was used to create a fully digital recording. In this configuration, it is possible for the audio to remain digital from the first AD converter after the [[mic preamp]] until it is in a [[CD player]].{{fact|date=July 2022}}

=== Pre-recorded albums ===
[[File:Kenwood DAT-140218-0002WP-crop.jpg|thumb|upright=1.25|DAT Recorder (Kenwood DX-7030)]]
[[File:Sony PCM-7030 of DR 20111102a-crop (cropped).jpg|thumb|upright=1.25|DAT was also used in professional environ&shy;ments like [[recording studio]]s and [[broadcasting]] institutions. The depicted device is a professional Sony PCM-7030 DAT recorder which had a recommended retail price of 8000 [[US dollars]].<ref>[http://www.datrecorders.co.uk/pcm7030.php Data on Sony PCM-7030] at datrecorders.co.uk</ref>]] 
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 (band)|Wire]] released their album ''[[The Ideal Copy]]'' on the format.<ref>{{Cite journal | title=Back in the Days of '88 | url=https://books.google.com/books?id=5oyYjDeNc_AC&pg=PA71 | journal=[[Spin (magazine)|Spin]] | volume=4 | issue=9 |date=December 1988 | page=71 | access-date=29 April 2011| last1=Media | first1=Spin L. L. C. }}</ref> 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 [[Factory Records discography|small number of albums]] on the format, including [[New Order (band)|New Order]]'s best-selling compilation ''[[Substance 1987]]'', but many planned releases were cancelled.<ref>{{cite web|url=http://www.cerysmaticfactory.info/dat_and_copycode_q.php|title=DAT and Copycode (Q Magazine article c.1988) – Factory Records|work=cerysmaticfactory.info}}</ref>

=== Amateur and home use ===
[[File:Original Sony DAT Walkman.JPG|thumb|upright=1.25|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 [[Taper (concert)|making]] and [[Tape trading|trading]] recordings of live music (see [[bootleg recording]]), since available DAT recorders predated affordable CD recorders. In the 1990s, fans of [[jam bands]], such as the [[Grateful Dead]] and [[Phish]], recorded and stored high-quality audience recordings of live concerts on the format.<ref>{{cite news |last1=Lei |first1=Richard |title=The Hottest Band the World Has Never Heard |url=https://www.washingtonpost.com/archive/lifestyle/style/1994/10/16/the-hottest-band-the-world-has-never-heard/a93436d8-b450-4d95-a995-ab2ac6ecfb12/ |newspaper=The Washington Post|access-date=26 November 2019 |date=16 October 1994}}</ref>

=== Computer data storage medium ===
{{Main article|Digital Data Storage}}
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&nbsp;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 [[backup]]s. 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 Corporation|Archive]] for [[Silicon Graphics|SGI workstations]])<ref>{{cite web|url=http://ask.slashdot.org/article.pl?sid=99/09/29/0451243|title=Can you Rip DAT audio? (Ask Slashdot forum thread)|publisher=Slashdot|access-date=25 October 2007|date=1 October 1999}}</ref> 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".<ref>{{cite web|url=http://homepage.ntlworld.com/adrian.rixon/personal/ade/dat-dds/drives.html |title=DAT/DDS hardware |date=26 March 2003 |access-date=25 October 2007 |archive-url=https://web.archive.org/web/20071016202400/http://homepage.ntlworld.com/adrian.rixon/personal/ade/dat-dds/drives.html |archive-date=16 October 2007 |url-status=dead}}</ref>

== See also ==
* [[ADAT]]
* [[Digital Audio Stationary Head]]
* [[Digital Data Storage]]
* [[Digital Tape Recording System]]
* [[Digital Compact Cassette]]
* [[Magnetic storage]]
* [[Magnetic tape]]
* [[MiniDisc]]
* [[NT (cassette)]]
* [[PCM adaptor]]
* [[ProDigi]]

== References ==
{{reflist}}

== External links ==
{{commons category multi|Digital Audio Tape|Sony products}}

{{Audio format}}
{{Music technology}}
{{Sony Corp}}

[[Category:Audio storage]]
[[Category:Digital audio]]
[[Category:Japanese inventions]]
[[Category:Portable audio players]]
[[Category:Products introduced in 1987]]
[[Category:Sony products]]
[[Category:Tape recording]]