The SPARS code is a three-position alphabetic classification system developed in the early 1980s by the Society of Professional Audio Recording Services (SPARS) for commercial compact disc releases to denote aspects of the sound recording and reproduction process, distinguishing between the use of analog equipment and digital equipment. The code's three positions refer to recording, mixing, and mastering respectively. The first two positions may be coded either "A" for analog or "D" for digital; the third position (mastering) is always "D" on digital CDs. The scheme was not originally intended to be limited to use on digital packaged media: it was also available for use in conjunction with analog releases such as vinyl or cassette (where the final character would always be "A"), but this was seldom done in practice.
The system was first implemented in 1984. Due to increasing complexity of recording and mixing processes developed over the code's first decade of use, SPARS decided to withdraw endorsement of the code in 1991 because they felt the code was overly simplistic and did not accurately reflect the complexity of typical recording and mixing processes in use at the time. However, many record labels continued to use the code and SPARS decided to re-endorse the SPARS code in 1995.
The three letters of the code have the following meanings:
Eight possible variants of the code exist:
As digital tape recorders only became widely available in the late 1970s, almost all recordings prior to this date that appear on CD will be AAD or ADD, having been digitally remastered. This means that the original analog master tape has been converted (transcribed) to digital. It does not always imply that there has been any additional editing or mixing, although this may have taken place.
In practice DAD was very rare, as many companies (especially the well-known classical music labels) used digital tape recorders (which were not prohibitively more expensive than analog tape recorders) during the editing or mixing stage.
The jewel box booklet and/or inlay of early compact discs included the SPARS code, typically DDD, ADD, or AAD. The typeface Combi Symbols CD includes the two common ways that the code was written on recordings.
Chris Stone and other members of the Society of Professional Audio Recording Services (SPARS) proposed the code with a set of guidelines for CD manufacturers to mark their product with an indication of exactly which parts of the recording process were analog and which were digital.[1]
The SPARS code was first introduced on commercial CD releases by PolyGram in 1984.[2]
SPARS withdrew endorsement of the code in 1991 due to confusion over analog and digital conversions and interfaces; many felt the SPARS code oversimplified and meaningless.[1] However, many labels continued to use it, and in 1995, the organization re-endorsed the code.[1]
The main limitation of the code is that it only covers the type of tape recorder used, not taking into account other equipment used in the production of the recording. For example, during the mixing stage (the middle letter in the code) many DDD recordings may have actually been converted from digital to analog, mixed on an analog mixing console, but converted back to digital and digitally recorded, thus earning it a D in the relevant part of the code. In addition to this, many recordings have effects or parts of different recordings added on to them, creating more confusion for the code.
Regardless of the quality of the recording, many DDD classical music compact discs typically sold for considerably more than their ADD counterparts of the same work, due to the so-called premium attached to the fledgling digital recording technology. For instance, Herbert von Karajan's and Berliner Philharmoniker's rendition of Beethoven's Symphony No. 3, an analogue recording from 1977 that won the Grand Prix du Disque, sold for considerably less than their 1984 digital recording of the same piece, though the newer recording was not particularly critically acclaimed.
These albums with common SPARS codes (AAD, ADD, DDD) are arranged by year of release on CD, where known:
Many older recordings previously issued on vinyl were reissued on CD, beginning with the format's commercial introduction in late 1982 (see Digital recording for a timeline). Reissue CDs often only have the original LP's copyright dates on them, so it's not obvious when the CDs were actually made. If they bear a SPARS code, though, the manufacture date was no earlier than 1984. Most of these older recordings were analog, so it's not unusual to see AAD and ADD codes, but occasional examples of digital-recording codes appear on later CD editions, such as these: