SPARS Code

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. The code denotes which parts of the recording process were completed using analog equipment and which were completed using digital equipment, encompassing three areas: recording, mixing and mastering. The first two positions, representing recording and mixing respectively, may be either an "A" for analog or a "D" for digital; the third position, representing mastering, is always "D" on digital CDs.

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:

There are five types:

Since CD is a digital medium, it must be produced from a digital master—therefore the last letter of the code will always be D. Newer LPs stored the music in analog format, yet they were often labeled as DDD, as the recording and mixing/editing were both digital.

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, AAD was uncommon and DAD was very rare, as many companies (especially the well-known classical music labels) used digital tape recorders (which was 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.

...
Wikipedia