Sharing CD knowledge: Let you know about the various versions of CD
London: Decca's record label, which was used to release its turntables in the US in 1947, was used by Kappa Records in the US. Currently, London also releases records outside the US. In 1929, it became the only record label in the British Isles to rival the century-old EMI.
I. About IFPI
CDs can be divided into early and late versions. CDs produced and released before 1994 are considered early CDs, while those produced and released after 1994 are considered late CDs. This is because 1994 saw the emergence of the IFPI (International Federation of the Phonographic Industry). Starting that year, all authentic CDs produced and released by record companies must have the IFPI code printed on the inner ring. CDs produced before 1994 did not have this code. One of the key features of reprints is the presence of the IFPI code on the inner ring.
Second, the types of multi-version CDs:
In the early days of manufacturing and releasing CDs, there were various versions of the same album.
Early CD versions are mainly divided into Japanese Sanyo version, Japanese SONY version, Japanese Denon version, Japanese Toshiba (TO) version, Japanese Mitsubishi version, West German version, French version, American version, Australian version, Korean version, and Hong Kong local version.
The approximate years of production and release are:
1. "Sanyo Edition" was published between 1986 and 1987 (with and without letterheads) 
2. "SONY version" refers to the period between 1985 and 1988 (divided into fine-circle English version, fine-circle no English version, regular version, and no star version)
3. The "Tianlong Edition" was published between 1986 and 1991 (divided into embossed and hollow-character editions) 
4. "Toshiba version" is from 1987 to 1992 (also called TO version) 
5. "Mitsubishi version" is from 1988 to 1990 (divided into MT version and non-MT version in the inner circle) 
6. The "West German Edition" was issued between 1983 and 1989 (the early editions were mainly silver-rimmed, while the later editions were mainly rubber-rimmed)
7. "Korean version" is from 1988 to 1994 (including Korean silver ring version (early Korean version), ordinary rubber ring version, T113 version, PAN ASIA version) 
8. The "French Edition" was released between 1989 and 1991 (early releases were mostly red, also known as the "Red French Edition"). 
9. The Australian version is from 1989 to 1991. 
10, the "American version" is from 1990 to 1991;
11. The "Hong Kong local version" began production in 1992-1993.
Regarding the sound quality ranking of different early versions, some collectors say:
The West German version ranked first, Sanyo version and SONY version tied for second, Denon version third, French version fourth, Toshiba version fifth, Korean Silver Circle version sixth, Mitsubishi version seventh, American version eighth, Australian version ninth, and Hong Kong local version last.
West German Silver Ring Edition: The most fundamental difference between a silver ring and an apron ring CD lies in the inner ring. The inner ring (partially or entirely) of a silver ring CD is silver, while the inner ring of an apron ring CD is made of clear plastic. Some first presses of records have silver rings, so a silver ring can sometimes be equated with a limited edition, unless the first release doesn't have a silver ring.
