ALL YOU WILL EVER NEED TO KNOW ABOUT LP's

A gramophone record, (also vinyl record, phonograph record, LP record, or simply record) is an analogue sound recording medium consisting of a flat disc with an inscribed modulated spiral groove. The recording is played back by rotating the disc at a constant angular velocity with a stylus (needle) placed in the groove, converting the vibrations of the stylus into an electric signal, and sending this signal through an amplifier to loudspeakers. 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 were supplanted in the late 1980s by digital media. Considering that many audio formats such as the 8-track had a heyday lasting only a few years, the longevity of the record is remarkable.

Basics

The normal commercial disc is engraved with two sound bearing concentric spiral grooves, one on each side of the disc, running from the outside edge towards the centre. Since the late 1910s, both sides of the record have been used to carry the grooves.

Common formats

* 12" (30 cm) 33? rpm long-playing (LP) format
* 12" (30 cm) 45 rpm extended-playing (12-inch (30 cm) single, Maxi Single and EP) format
* 10" (25 cm) 78 rpm (single) format
* 7" (17.5 cm) 45 rpm (single) format

Less common formats

* 16" (40 cm) 33? rpm long-playing (LP) format used for transcriptions of radio programs. Late 1940s.
* 10" (25 cm) 33? rpm long-playing (LP) format — more common in the 1950s
* 10" (25 cm) 45 rpm extended-playing (EP) format
* 7" (17.5 cm) 33? rpm extended-playing (EP) format
* 16? rpm format for "talking books" (voice) [1] [2]
* 16? rpm 7" Chrysler "Highway Hi-fi;" much-ballyhooed; unsuccessful; introduced 1956, discontinued 1958; 550 grooves/inch required 0.25-mil stylus (narrower than microgroove); apparently no more than 42 titles ever issued [3], [4]
* 12" (30 cm), 10" (25 cm) and 7" (17.5 cm) picture discs and shaped discs
* Specialty sizes (5" (12 cm), 6" (15 cm), 8" (20 cm), 9" (23 cm), 11" 28 cm), 13" (33 cm))
* Flexidiscs, sometimes square 7"s (17.5 cm) played at 33? rpm.

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 when the stylus head is dropped carelessly onto the LP. Towards the label centre, at the end of the groove there is another silent section known as the lead-out, where 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.

Between each track on the recorded section of a record there is usually a short gap where the groove is widely spaced. This space called a "rill" and is clearly visible making it easy to find a particular track.

Early history of the medium

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: in the mid-1910s, disk records overtook cylinders in popularity, and would dominate the market until the 1990s. Amberol cylinders ceased production in the late 1920s.

Recording the disc

For the first several decades of disc record manufacturing, sound was recorded directly on to the master disc (also called the matrix, sometimes just the master) at the recording studio. From about 1950 on (earlier for some large record companies, later for some small ones) it became usual to have the performance first recorded on audio tape, which could then be processed and/or edited, and then dubbed on to the master disc.

A record cutter would engrave the grooves into the master disc. Early on these master discs were soft wax, later on a harder lacquer was used.

The mastering process was originally something of an art as the operator had to manually allow for the changes in sound which affected how wide the space for the groove needed to be on each rotation. Sometimes the engineer would sign his work, or leave humorous or cryptic comments in the run-off groove area, where it was normal to scratch or stamp identifying codes to distinguish each master.

Record Labels

Record companies organised their products into labels. These could either be subsidiary companies, or they could simply be just be a brand name. For example, EMI published records under the His Master's Voice (HMV) label which was their classical recording brand, Harvest for their progressive rock brand, home to Pink Floyd. They also had Music for Pleasure and Classics for Pleasure as their economy labels. EMI also used the Parlophone brand in the UK for Beatles records in the early 1960's.

In the 1970's, successful musicians sought greater control and one way they achieved this was with their own labels, though normally they were still operated by the large music corporations. One of the most famous early examples of this was the Beatles' Apple Records.

In the late 1970's, the anarchic punk rock movement gave rise to the independent record labels. These were not owned or even distributed by the main corporations. In the UK, examples were Stiff Records who published Ian Dury and the Blockheads and Two Tone Records, label for The Specials. These allowed smaller bands to step onto the ladder without having to conform to the rigid rules of the large corporations.

Recording medium comparison

Format Typical length
78 record around 3.5 minutes per side
45 record around 4 minutes (EP: 7 minutes) per side
LP record up to 30 minutes per side
Audio cassette usually 30 or 45 minutes per side, 60 minutes per side have also been sold.
8-Track up to 76 minutes
Compact disc Earlier discs: up to 74 minutes (or up to 650 MB of MP3 files)
Later discs: up to 80 minutes (or up to 700 MB of MP3 files)
MP3 player around 17 hours per GB of data, depending on bit rate

The typical duration of a vinyl album was about 15 to 25 minutes per side, except classical music which could extend to over 30 minutes on a side. If a side exceeds the average time, the maximum groove amplitude is reduced to make room for the additional program material. This can cause hiss in the sound from lower quality amplifiers when the volume is turned up to compensate for the lower recorded level. An extreme example, Todd Rundgren's Initiation LP, with 36 minutes of music on one side, has a "technical note" at the bottom of the inner sleeve: "if the sound does not seem loud enough on your system, try re-recording the music onto tape." The total of around 40–45 minutes often influenced the arrangement of tracks, with the preferred positions being the opening and closing tracks of each side. With the advent of compact discs, the available time became 74 or 80 minutes in a single block, which reduced the previous constraints.

Although the term EP was commonly used to describe a 7" single with more than two tracks, technically they were not different from a normal 7" single. The EP used reduced dynamic range and a smaller run-off groove area to extend the playing time. However, there are examples of singles, such as The Beatles' "Hey Jude" or Queen's "Bohemian Rhapsody", which were six minutes long or more. These longer recordings would require the same technical approach as an EP. The term EP has also been used for 10" 45 rpm records, typically containing a reduced number of tracks.

Vinyl albums had a large 12" album cover, which also allowed cover designers scope for imaginative designs, often including fold-outs and leaflets.

Records in the present day

Groove recordings, first designed in the final quarter of the 19th century, held a predominant position for an impressive amount of time - just about a century - withstanding competition from reel-to-reel tape, the 8-track tape and the compact casette. However, by 1988, the compact disc had surpassed the gramophone record in popularity.

In spite of their obvious flaws, such as the lack of portability, records still have enthusiastic supporters. Vinyl records continue to be manufactured and sold today, although record sales are considered to be a niche market comprised of audiophiles, collectors, and disc jockeys (DJs) that perform live remixes. Second-hand records are also available, often very cheaply. Old records in particular are in much demand by collectors the world over.

Arguments about sound fidelity

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 (e.g. 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 natural 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 arguments about the superior quality of vinyl records are wide-ranging. Proponents of analog audio argue that, unlike CD audio, it is not affected by the sharp frequency cutoff and phase characteristics, including group delay, near the Nyquist frequency and the quantization noise of 16-bit linear quantization, but that analog recording has a more gradual frequency cutoff, and what they consider to be a more natural descent into the analog noise floor.

Proponents of digital audio state that these differences are generally inaudible to normal human hearing, and the lack of clicks, hiss and pops from digital recordings greatly improved sound fidelity. They also state that more modern anti-aliasing filters and oversampling systems used in modern CD recordings greatly reduce the problems observed with early CDs.

CDs are not subject to physical wear in normal use, whereas even a high quality pickup will wear the surface of a record and cause noticeable degradation over time. However this depends on the wear-resistance of the record itself, which is subject to the quality of the surface material used. Though neither medium is immune from damage, CDs are more robust and modern CD players can play discs without noticeable problems even when scratched (Reed-Solomon error correction); a vinyl record suffering the same treatment could well be unplayable. Poorly made CDs however, are subject to a form of "wear" known as disc rot, laser rot or CD rot. This is due to the oxidisation of the aluminium layer, degrading reflective properties and thus increasing error rate.

The "warmer" sound of analog records is generally believed on both sides of the argument to be an artifact of the dynamic harmonic distortion characteristic of vinyl recording. It is thought by supporters of digital audio that the fans of vinyl got so used to it they think it is actually more "faithful" to the real sound, when it is actually the other way around. (This phenomenon of a preference for the sound of a beloved lower-fidelity technology is not new; a 1963 review of RCA Dynagroove recordings notes that "some listeners object to the ultra-smooth sound as ... sterile ... such distortion-forming sounds as those produced by loud brasses are eliminated at the expense of fidelity. They prefer for a climactic fortissimo to blast their machines...")

Nevertheless, critics of compact disc audio have observed that more recent digital audio systems are being designed to use higher sampling rates (for example, 96 kHz) and finer quantization (for example 24 rather than 16 bits per sample), and state that this would not be done if it did not bring some audible improvement to the output. However, this is a fallacy. The use of high sampling rates beyond 44.1 kHz is seen by many digital audio enthusiasts (and even some professionals) as being unnecessary (see Nyquist frequency)[7]. Although finer quantization would theoretically bring about audio improvements, some believe this might not be noticeable to most human ears. The use of finer quantization does allow more resolution during the mastering process, where a recording might end up in a final mix at a much reduced amplitude and hence use fewer bits. By recording at a much finer resolution, too much degradation in the processing is avoided; it is easy to discard data, but it can't be recreated if it was never recorded.

Disc jockeys

For disc jockeys ("DJs"), mostly in the electronic dance music or hip hop genres, vinyl has another advantage over the CD — direct manipulation of the medium. With CDs or compact audio cassettes one normally has only indirect manipulation options, e.g., the play, stop and pause buttons. With a record one can place the stylus a few grooves farther in or out, accelerate or decelerate the turntable, or even reverse its direction, provided the stylus, record player and the "black record" itself are built to withstand it. Some professional CD machines now have this capability.

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

Various other laser-based turntables were tried during the 1990s, but while a laser reads the groove very accurately, since it does not touch the record, the dust that vinyl naturally attracts due to static charge is not cleaned from the groove.