Vinyl Records
A gramophone record (also phonograph record, or simply record) is an analogue sound recording medium consisting of a flat disc with an inscribed modulated spiral groove. Gramophone records were the primary technology used for personal music reproduction for most of the 20th century. They replaced the phonograph cylinder in the 1910s, and although they were supplanted in popularity in the late 1980s by digital media, they continue to be manufactured and sold as of 2006.
The terms LP record (LP), 45rpm record (45), and 78rpm record (78) each refer to specific types of gramophone records. LPs and 45s are usually made of polyvinyl chloride (PVC), and hence may be referred to as vinyl records or simply vinyl.
Early history
RCA logo with Nipper, the RCA/HMV dog.A sound recording and reproduction device utilizing what were essentially disk records was described by Charles Cros of France in 1877 but never built. In 1878, Thomas Edison independently built the first working phonograph, a tinfoil cylinder machine, intending it for use as a voice recording medium, typically for office dictation. The phonograph cylinder dominated the recorded sound market beginning in the 1880s. Disc records were invented by Emile Berliner in 1888, and were used exclusively in toys until 1894, when Berliner began marketing disk records under the Berliner Gramophone label. The Edison "Blue Amberol" cylinder was introduced in 1912, with a longer playing time of around 4 minutes (at 160 rpm) and a more resilient playing surface than its wax predecessor, but the format was doomed due to the difficulty of reproducing recordings. In the mid-1910s, disk records overtook cylinders in popularity, and would dominate the market until the 1980s. Production of Amberol cylinders ceased in the late 1920s.
Materials
Edison cylinder phonograph ca. 1899Early disc records were originally made of various materials including hard rubber. From 1897 onwards, earlier materials were largely replaced by a rather brittle formula of 25% "shellac" (a material obtained from the excretion of a southeast Asian beetle), a filler of a cotton compound similar to manila paper, powdered slate and a small amount of a wax lubricant. The mass production of shellac records began in 1898 in Hanover, Germany. Shellac records were the most common until the 1950s. Unbreakable records, usually of celluloid (an early form of plastic) on a pasteboard base, were made from 1904 onwards, but they suffered from an exceptionally high level of surface noise.
In the 1890s the early recording formats of discs were usually seven inches (nominally 17.5 cm) in diameter. By 1910 the 10-inch (25.4cm) record was by far the most popular standard, holding about three minutes of music or entertainment on a side. From 1903 onwards, 12-inch records (30.5cm) were also commercially sold, mostly of classical music or operatic selections, with four to five minutes of music per side.
Such records were usually sold separately, in plain paper or cardboard sleeves that may have been printed to show producer of the retailer's name and sometimes in collections held in paper sleeves in a cardboard or leather book, similar to a photograph album, and called record albums. Also, empty record albums were sold that customers could use to store their records.
While a 78 rpm record is brittle and relatively easily broken, both the microgroove LP 33⅓ rpm record and the 45 rpm single records are made from vinyl plastic which is flexible and unbreakable in normal use. 78s come in a variety of sizes, the most common being 10 inch (25 cm) and 12 inch (30 cm) diameter, and these were originally sold in either paper or card covers, generally with a circular cutout allowing the record label to be seen. The Long-Playing records (LPs) usually come in a paper sleeve within a colour printed card jacket which also provides a track listing. 45 rpm singles and EPs (Extended Play) are of 7 inch (17.5 cm) diameter, the earlier copies being sold in paper covers.
In 1930, RCA Victor launched the first commercially-available vinyl long-playing record, marketed as "Program Transcription" discs. These revolutionary discs were designed for playback at 33⅓ rpm and pressed on a 30 cm diameter flexible plastic disc. In Roland Gelatt's book The Fabulous Phonograph, the author notes that RCA Victor's early introduction of a long-play disc was a commercial failure for several reasons including the lack of affordable, reliable consumer playback equipment and consumer wariness during the Great Depression. A good outline of this unsuccessful product launch can be found here.
However, vinyl's lower playback noise level than shellac was not forgotten. During and after World War II when shellac supplies were extremely limited, some 78 rpm records were pressed in vinyl instead of shellac (wax), particularly the six-minute 12" (30 cm) 78 rpm records produced by V-Disc for distribution to US troops in World War II.
Beginning in 1939, Columbia Records continued development of this technology. Dr. Peter Goldmark and his staff undertook exhaustive efforts to address problems of recording and playing back narrow grooves and developing an inexpensive, reliable consumer playback system. In 1948, the 12" (30 cm) Long Play (LP) 33⅓ rpm microgroove record was introduced by the Columbia Record at a dramatic New York press conference.
Speeds
Earliest speeds of rotation varied widely, but by 1910 most records were recorded at about 78 to 80 rpm. In 1925, 78.26 rpm was chosen as a standard for motorized phonographs, because it was suitable for most existing records, and was easily achieved using a standard 3600-rpm motor and 46-tooth gear (78.26 = 3600/46). Thus these records became known as 78s (or "seventy-eights"). This term did not come into use until after World War II when a need developed to distinguish the 78 from other newer disc record formats, an example of a retronym. Earlier they were just called records, or when there was a need to distinguish them from cylinders, disc records. Standard records was also used, although the same term had also been used earlier for two-minute cylinders.
After World War II, two new competing formats came on to the market and gradually replaced the standard "78": the 33⅓ rpm (often just referred to as the 33 rpm), and the 45 rpm. The 33⅓ rpm LP (for "long play") format was developed by Columbia Records and marketed in 1948. RCA Victor developed the 45 rpm format and marketed it in 1949, in response to Columbia. Both types of new disc used narrower grooves, intended to be played with a smaller stylus - typically 0.001" (25 µm) wide, compared to 0.003" (76 µm) for a 78 - so the new records were sometimes called Microgroove. In the mid-1950s all record companies agreed to a common recording standard called RIAA equalization; before then each company had used its own preferred standard, requiring discriminating listeners to use preamplifiers with multiple selectable equalization curves.
The older 78 format continued to be mass produced alongside the newer formats into the 1950s (and in a few countries, such as India, into the 1960s - Beatles 78s produced in India are among the most collectable Beatles releases).
The commercial rivalry between RCA Victor and Columbia Records led to RCA Victor's introduction of what it had intended to be a competing vinyl format, the 7" (17.5 cm) / 45 rpm Extended Play (EP). For a two-year period from 1948 to 1950, record companies and consumers faced uncertainty over which of these formats would ultimately prevail in what was known as the "War of the Speeds". (See also format war)
Eventually, the 12" (30 cm) / 33⅓ rpm LP prevailed as the predominant format for musical albums, and the 7" (17.5 cm) / 45 rpm EP or "single" established a significant niche for shorter duration discs typically containing one song on each side. The EP discs typically emulated the playing time of the former 78 rpm discs, while the LP discs provided up to one-half hour of time per side (though typically 15 to 20 minutes). Extended play was only achieved at the expense of heavy compression or attenuating the bass (as the groove actually visibly followed the wave-form, loud or low-frequency sounds consumed more width per revolution than quiet sounds).
From the mid-1950s through the 1960s, in the U.S. the common home "record player" or "stereo" would typically have had these features: a three- or four-speed player with changer (78, 45, 33⅓, and sometimes 16⅔ rpm); a combination cartridge with both 78 and microgroove styluses; and some kind of adapter for playing the 45s with their larger center hole. The large center hole on 45s allows for easier handling by jukebox mechanisms.
Deliberately playing records at the wrong speed was a near-universal childhood amusement. The musical artist David Seville actually invented the novelty musical genre known as "chipmunk" music by making a recording of himself at 33⅓ rpm and then having the recording played back at 45 rpm, thus changing the timbre of his voice to something that supposedly sounded like the anthropomorphism of a chipmunk.
As late as the 1970s, some children's records were released at the 78 rpm speed.
Structure of a typical record
The majority of records are pressed on black vinyl. The colouring material used to blacken the transparent PVC plastic mix is carbon black, the generic name for the finely divided carbon particles produced by the incomplete burning of a mineral oil sourced hydrocarbon. Without this, the record would be transparent and would show the dirt collected in the grooves, the scratch marks and other damage to both sides of the record. Carbon black also increases the strength of the disc.
Some records are pressed on coloured vinyl (other than black) or with paper pictures embedded in them ("picture discs"). These discs can become collectors' items in some cases, although rarity is not guaranteed - sometimes, the records are just pressed on coloured vinyl at the wishes of the clients. During the 1980s there was a trend for releasing singles on colour vinyl — sometimes with large inserts that could be used as posters — this trend has been revived of late and has succeeded in continuing to make 7" singles a viable format (perhaps surprisingly, sales of 7" singles are buoyant in some markets).
Vinyl record standards for the United States follow the guidelines[5] of the RIAA (the Record Industry Association of America). The inch designations are nominal, and are not accurate indications of the diameter. The actual dimension of a 12 inch record is 302 mm (11.89 in), for a 10 inch it is 250 mm (9.84 in), and for a 7 inch it is 175 mm (6.89 in).
Records made in other countries are standardized by different organizations, but are very similar in size. The record diameters are typically 300 mm, 250 mm and 175 mm in most countries.
There is an area around 6 mm (0.25″) wide at the outer edge of the disk, called the lead-in where the groove is widely spaced and silent. This section allows the stylus to be dropped at the start of the record groove, eliminating the risk of damage to the recorded section of the groove if the stylus head is dropped carelessly onto the record.
Between each track on the recorded section of a LP record, there is usually a short gap of around 1 mm (0.04") where the groove is widely spaced. This space is clearly visible, making it easy to find a particular track.
Towards the label centre, at the end of the groove, there is another wide-pitched section known as the lead-out. At the very end of this section, the groove joins itself to form a complete circle; when the stylus reaches this point, it circles repeatedly until lifted from the record. Automatic turntables rely on the position of the arm, as it reaches these more widely spaced grooves, to trigger a mechanism that raises the arm and moves it out of the way of the record.
The catalog number and other information is written or stamped in the space between the groove in the lead-out on the master disc, resulting in visible recessed writing on the final version of a record. Sometimes, the cutting engineer might add handwritten comments or their signature, if they are particularly pleased with the quality of the cut.
When auto-changing turntables were commonplace, 7-inch records were typically pressed with a raised (or ridged) outer edge and label area. This would allow records to be stacked onto each other, gripping each other without the delicate grooves coming into contact, thus reducing the risk of damage. Auto-changing turntables included a mechanism to support a stack of several records above the turntable itself, dropping them one at a time onto the active turntable to be played in order. Many longer sound recordings, such as complete operas, were interleaved across several 10-inch or 12-inch discs for use with auto-changing mechanisms, so that the first disk of a three-disk recording would carry sides 1 and 6 of the program, while the second disk would carry sides 2 and 5, and the third, sides 3 and 4, allowing sides 1, 2, and 3 to be played automatically, then the whole stack reversed to play sides 4, 5, and 6.
Progress, and the war of the speeds
About the same time the most common substance for making 33 rpm disc records became vinyl, while 45 rpm discs were made from either vinyl or polystyrene. All speeds of records were made in various sizes, mainly 17.5, 25, 30 cm (~7, 10 and 12 inches diameter); the 17.5 cm (~7-inch) being most common for the 45 rpm, the 25 cm (~10-inch) for the 78 (and the first few years of 33⅓ production), and the 30 cm (~12-inch) for the 33 from the mid 1950s on.
Vinyl quality
The sound quality and durability of vinyl records is highly dependent on the quality of the vinyl used. During the early 1970s, as a cost-cutting move towards use of lightweight, flexible vinyl pressings, much of the industry adopted a technique of reducing the thickness and quality of vinyl used in mass-market manufacturing, marketed by RCA Victor as the "Dynaflex" (125 g/m²) process. Most vinyl records are pressed on recycled vinyl.
New "virgin" or "heavy" (180-220 g/m²) vinyl 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. Many classic rock albums have been reissued on 180 g/m² vinyl, such as The Residents' Meet The Residents and catalogues of The Clash. Modern albums like Shellac's and Mission of Burma's latest are also commonly pressed on 180 g/m². Many collectors prefer to have 180 gram vinyl albums, and also, they have been reported to have a better sound than normal vinyl. These albums tend to withstand the deformation caused by normal play better than regular vinyl.
Since most vinyl records are from recycled plastic, it can lead to impurities in the record, causing a brand new album to have audio artifacts like clicks and pops. Virgin vinyl means that the album is not from recycled plastic, and thus, will be immune from the possible impurities of recycled plastic.
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 in 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.
Stereo and beyond
In 1958 the first stereo two-channel records were issued – by Audio Fidelity in the USA and Pye in Britain, using the Westrex "45/45" single-groove system. While the stylus moves horizontally on monophonic records, on stereo records the stylus moves vertically as well as horizontally.
One could envision a system in which the left channel was recorded laterally and the right channel was recorded with a "hill-and-dale" vertical motion, and such systems were actually proposed, but not adopted. In the Westrex system, each channel drives the stylus at a 45 degree angle to the vertical. During playback, the combined signal is sensed by a left channel coil mounted diagonally opposite the inner side of the groove, and a right channel coil mounted diagonally opposite the outer side of the groove [6].
It is, however, helpful to think of the motion in terms of the vector sum and difference of the two channels. Effectively, horizontal stylus motion carries an L+R sum signal, and vertical stylus motion carries an L-R difference signal. The advantages of the 45/45 system are:
greater compatibility with monophonic recording and playback systems. A monophonic cartridge will reproduce an equal blend of the left and right channels instead of reproducing only one channel. Conversely, a stereo cartridge reproduces the lateral grooves of monophonic recording equally through both channels, rather than one channel.
a more balanced sound, because the two channels have equal fidelity (rather than providing one higher-fidelity laterally recorded channel and one lower-fidelity vertically-recorded channel);
higher fidelity in general, because the "difference" signal is usually of low power and thus less affected by the intrinsic distortion of hill-and-dale recording.
This system was invented by Alan Blumlein of EMI in 1931, and patented the same year. EMI cut the first stereo test discs using the system in 1933. However it was not exploited commercially until a quarter of a century later.
Stereo sound provides a more natural listening experience where the spatial location of the source of a sound is, at least in part, reproduced.
The development of quadraphonic records was announced in 1971 - which recorded four separate sound signals. This was achieved on the two stereo channels by electronic matrixing, where the additional channels were combined into the main signal. When the records were played, circuits in the amplifiers were able to decode the signals into four separate channels. There were two main systems of matrixed quadrophonic records produced, confusingly named SQ (by CBS) and QS (by Sansui). They proved commercially unsuccessful, but were an important precursor to later 'surround sound' systems, as seen in SACD and home cinema today. A different format, CD-4 (by RCA), encoded rear-channel information on an ultrasonic carrier, which required a special wideband cartridge to pick it up. Typically the high-frequency information wore off after only a few playings, and CD-4 was even less successful than the two matrixed formats.
Other developments
In 1951, under the direction of C. Robert Fine, Mercury Records initiated a minimalist single-microphone monaural recording technique. The first record, Kubelik/Chicago's performance of "Pictures at an Exhibition" was described as "being in the living presence of the orchestra" by the NY Times music critic. The series of records was then named “Mercury Living Presence.” In 1955, Mercury began 3-channel stereo recordings, still based on the principle of the single microphone. The center (single) mic was of paramount importance, with the two side mics adding depth and space, record masters were cut directly from a 3-track to 2-track mixdown console, with all editing of the master tapes done on the original 3-tracks. In 1961, Mercury enhanced this technique with three-microphone stereo recordings using 35mm magnetic film instead of half-inch tape for recording. The greater thickness and width of 35mm magnetic film prevented tape layer print-through and pre-echo and gained in addition extended frequency range and transient response. The Mercury Living Presence recordings were remastered to CD in the 1990s, by the original producer, using the same method of 3-to-2 mix directly to the master recorder.
On a small number of early phonograph systems and radio transcription discs, as well as some entire albums, such as Goodbye Blue and White by Less Than Jake, the direction of the groove is reversed, beginning near the centre of the disc and leading to the outside. A small number of records (such as Jeff Mills' Apollo EP or the Hidden In Plainsight EP from Detroit's Underground Resistance) were manufactured with multiple separate grooves to differentiate the tracks (usually called 'NSC-X2'). X2 was pioneered by Ron Murphy and Heath Brunner from Sound Enterprises (formerly National Sound Corporation), a record mastering company in Detroit.
In the late 1970s, "direct-to-disc" records were produced, aimed at an audiophile niche market, which completely bypassed use of magnetic tape in favor of a "purist" transcription directly to the master lacquer disc. Also during this period, "half-speed mastered" and "original master" records were released, using expensive state-of-the-art technology.
The early 1980s saw the introduction of "DBX-encoded" records, again for the audiophile niche market. These were completely incompatible with standard record playback preamplifiers, relying on the DBX compandor encoding/decoding scheme to greatly increase dynamic range (DBX encoded disks were recorded with the dynamic range compressed by a factor of two in dB: quiet sounds were meant to be played back at low gain and loud sounds were meant to be played back at high gain, via automatic gain control in the playback equipment; this reduced the effect of surface noise on quiet passages). A similar and very short-lived scheme involved using the CBS-developed "CX" noise reduction encoding/decoding scheme.
Also in the late 1970s and 1980s, a method to improve the dynamic range of mass-produced records involved highly advanced disc cutting equipment. These techniques, marketed as the CBS Discomputer and Teldec Direct Metal Mastering, were used to reduce inner-groove distortion