Similarly, the introduction of high-quality but expensive quadraphonic (four channel) reel-to-reel tapes and 8-track tape cartridges in 1970 led to the introduction of quadraphonic vinyl records, which arrived on the market in 1972. Although public interest was initially high, the lack of compatibility between the three competing SQ, QS, and CD-4 formats prompted the eventual commercial failure of quadraphonic LP records. Most record companies stopped producing quadraphonic LPs after 1975 although a handful of classical-music titles continued to be issued until 1980.

Other major developments worth noting:

During the early 1970s, a cost-cutting move towards use of lighweight, flexible vinyl pressings. Marketed by RCA Victor as the Dynaflex process, much of the industry adopted a technique of reducing the thickness and quality of vinyl used in mass-market manufacturing. In many cases, this included using "regrind" vinyl as a means of cutting manufacturing costs.

During the late 1970s, an audiophile-focused niche market for "direct-to-disc" records, which completely bypassed use of magnetic tape in favor of a "purist" transcription directly to the master lacquer disc.

During the early 1980s, an audiophile-focused niche market for "DBX-encoded" records, which were completely non-compatible with standard record playback preamplifiers, relying on a sophisticated DBX noise reduction encoding/decoding scheme to virtually eliminate playback noise and increase dynamic range. A similar and very short-lived scheme involved using the CBS-developed "CX" noise reduction encoding/decoding scheme.

During the late 1970s, an audiophile-focused niche market for "half-speed mastered" and "original master" records, using expensive state-of-the-art technology.

During the late 1970s and 1980s, the use of highly advanced disc cutting equipment to improve the dynamic range and reduce inner-groove distortion of mass-produced records, using techniques marketed as the CBS Discomputer and Teldec Direct Metal Mastering.

Although replaced by digital media such as the compact disc as a mass market music medium, vinyl records continue to be manufactured and sold in the 21st century.

Historically the most common formats are:

12" (30 cm) / 33? rpm LP
7" (17.5 cm) / 45 rpm EP or Single
followed by

10" (25 cm)/ 45 rpm LP (superceeded by 12" (30 cm) / 33? rpm LP in the 60's)
12" (30 cm) / 33 or 45 rpm Maxi Single (introduced in the 80's)
Today most of the records are issued in 12" (30 cm) LP or Maxi Single.

The sound quality and durability of vinyl records is highly dependent on the quality of the vinyl used. Most vinyl records are pressed on recycled vinyl. New "virgin" or "heavy" (180-220 gram) is commonly used for classical music, although it has been used for some other genres. Today, it is increasingly common in vinyl pressings that can be found in most record shops. Even modern albums like Shellac's and Mission of Burma's latest are pressed on 180 g/m² vinyl, though most are reissues of classic albums, like The Clash's series of reissues. These albums tend to withstand the deformation caused by normal play better than regular vinyl.

While most vinyl records are pressed from metal master discs, a technique known as lathe-cutting was introduced in the late 1980s by Peter King of Geraldine, New Zealand. A lathe is used to cut microgrooves into a clear polycarbonate disc. Lathe cut records can be made inexpensively in small runs. However, the sound quality is significantly worse than proper vinyl records, and lathe cut records tend to degrade further in quality after repeated playing.

Vinyl vs. compact discs
In the early days of compact discs, vinyl records were still prized by audiophiles because of better reproduction of analog recordings, however the drawback was greater sensitivity to scratches and dust. Early compact discs were perceived by some as screechy, distorting sounds on the high end, and not as "warm" as vinyl especially in recordings that require a wide dynamic range (eg. classical recordings). This resulted in a slower acceptance of digital music in its early years by some listeners.

Though digital audio technology has improved over the years, some audiophiles still prefer what they perceive as the warmer and more detailed sound of vinyl over the harsher sound of CDs. Some listeners were also disappointed by what they considered to be unfaithful remastering of analog recordings. The advent of higher-quality digital formats, notably SACD, offers the tantalizing possibility of combining the high-quality sound of the best analog recordings with the convenience and durability of the CD. Many artists still release recordings, in limited pressings, on vinyl.

For DJs, mostly in the electronic dance music or hip hop genres, vinyl has another advantage over the CD: the direct manipulation of the medium. While with CDs or cassettes one normally has only indirect manipulation options (the play/stop/pause etc. buttons), with a record one can put the needle a few tracks farther in- or outwards and accelerate/decelerate the spinning or even reverse the direction (if the needle and record player is built to withstand it). However some professional CD players now have this capability.

One company has developed a player that uses a laser instead of a needle to read vinyl discs. In theory, it eliminates the possibility of scratches and attendent degradation of the sound, but its expense limits use primarily to digital archiving of analog records.

--------------------------------------------------------------------------------
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Metasyntactic variable".