Phonograph

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The phonograph, or gramophone, was the most common device for playing recorded sound from the 1870s through the 1980s.

Contents 1 Terminology 1.1 United Kingdom 1.2 United States 1.3 Australia 2 History 2.1 Phonautograph 2.2 Phonograph theory 2.3 First phonograph 2.4 Thomas Edison's Account of inventing the Phonograph 2.5 Oldest surviving recordings 3 Disc versus cylinder as a recording medium 4 Dominance of the gramophone record 5 Turntable technology 5.1 Turntable construction 5.2 Turntable drive systems 5.2.1 Idler-wheel drive system 5.2.2 Belt drive system 5.2.3 Direct drive system 6 Pickup systems 6.1 Piezoelectric (crystal/ceramic) cartridges 6.2 Magnetic cartridges 6.3 Optical readout 7 Styli 8 Equalization 9 Arm systems 9.1 Direct vs belt drive 10 See also 11 References 12 External links

[edit] Terminology

Usage of these terms is not uniform across the English-speaking world (see below). In more modern usage, this device is often called a turntable, record player, or record changer.

The famous phonograph was the first device for recording and replaying sound. The term phonograph ("sound writer") is derived from the Greek words φωνή (meaning "sound" or "voice" and transliterated as phoné) and γραφή (meaning "writing" and transliterated as graphé). Similar related terms gramophone and graphophone have similar root meanings. The coinage, particularly the use of the -graph root, may have been influenced by the then-existing words phonographic and phonography, which referred to a system of phonetic shorthand; in 1852 The New York Times carried an advertisement for "Professor Webster's phonographic class", and in 1859 the New York State Teachers' Association tabled a motion to "employ a phonographic recorder" to record its meetings.

F. B. Fenby was the original author of the word phonograph. An inventor in Worcester, Massachusetts, he was granted a patent in 1863 for an unsuccessful device called the "Electro-Magnetic Phonograph".^[1] His concept detailed a system that would record a sequence of keyboard strokes onto paper tape. Although no model or workable device was ever made, it is often seen as a link to the concept of punched paper for player piano rolls (1880s), as well as Herman Hollerith's punch card tabulator (used in the 1890 census), a distant precursor of the modern computer.

Arguably, any device used to record sound or reproduce recorded sound could be called a type of "phonograph", but in common practice it has come to mean historic technologies of sound recording.

In the late 19th and early 20th century, the alternative term talking machine was sometimes used. This term was more in line with Thomas Edison's early view that his invention was better suited for spoken recordings such as dictation than for musical recordings.

[edit] United Kingdom

In British English, gramophone came to refer to any sound reproducing machine using disc records, as disc records were popularized in the UK by the Gramophone Company. The term phonograph is usually restricted to devices playing cylinder records. The term gramophone would generally be taken to refer to a wind-up machine, and from the 1960s onwards the more common term would be record player or turntable as part of a system that also played cassettes and included radio. Such a system would be called a hi-fi or stereo (most systems being stereophonic by the mid-1960s). Gramophone took its name from the Greek words "γραμμή" (grami, line) and "φωνή" (phoni, voice). Like other, similar devices the marketers of which wanted to express the notion of "sound" in the devices' names, they also used the same part of the Greek word (e.g., telephone, microphone etc.).

[edit] United States

In American English, phonograph was the most common generic term for any early sound reproducing machine, until the second half of the 20th century, when it became archaic and record player became the universal term for disc record machines. In contemporary American usage phonograph most usually refers to disc record machines or turntables, the most common type of analogue recording from the 1910s on.

Gramophone was a U.S. brand name, and as such in the same category as Victrola, Zon-o-phone, Graphophone and Graphonola referring to specific brands of sound reproducing machines. (Similarly, in German, das Grammophon (literally "the Gramophone") was the most common generic term for any sound reproducer using grooved records, hence the brand name Deutsche Grammophon.) Emile Berliner's Gramophone was considered a type of phonograph.

The brand name Gramophone was not used in the USA after 1901, and the word fell out of use there, though it has survived in its nickname form, Grammy, as the title of the Grammy Awards. The Grammy trophy itself is a small rendering of a gramophone,

[edit] Australia

In Australian English, record player was the term; turntable was a more technical term; gramophone was restricted to the old mechanical (i.e., wind-up) players; and phonograph was used as in British English.

[edit] History

[edit] Phonautograph

The earliest known invention of a phonographic recording device was the phonautograph, invented by Frenchman Édouard-Léon Scott de Martinville and patented on March 25, 1857. It could transcribe sound to a visible medium, but had no means to play back the sound after it was recorded. The device consisted of a horn or barrel that focused sound waves onto a membrane to which a hog's bristle was attached, causing the bristle to move and enabling it to inscribe the sound onto a visual medium. Initially, the phonautograph made recordings onto a lamp-blackened glass plate. A later version (see image) used a medium of lamp-blackened paper on a drum or cylinder. Another version would draw a line representing the sound wave on a roll of paper. The phonautograph was a laboratory curiosity for the study of acoustics. It was used to determine the frequency of a given musical pitch and to study sound and speech; it was not understood at that time, that the waveform recorded by the phonautograph was in fact a recording of the sound wave that needed only a playback mechanism to reproduce that sound.

In 2008, phonautograph recordings were for the first time played back as sound by American audio historians.^[2][3] The team accessed Leon Scott's phonautograph papers which were stored in France's patent office and the Académie des Sciences. They then optically scanned the etched paper recordings into a computer program developed a few years earlier for the Library of Congress. The sound waves on the paper were then translated by the computer into audible sounds. One recording, created on April 9, 1860 was revealed to be a 10-second recording (low fidelity but just recognizable) of a singer performing the French folk song "Au Clair de la Lune". This phonautogram is the earliest known recording of a human voice to be played back.^[3] predating Frank Lambert's 1878 recording of a talking clock by nearly two decades and the Edison Company's 1888 phonographic recording of a Handel concert by nearly three decades.

Since the above recording was recovered, the same team have succeeded in recovering a 1859 recording of a 435 Hz tuning fork, (at that time the French standard concert pitch, now internationally 440 Hz), possibly made to test the machine's ability. This latter recording is thus the oldest known recording of a recognisable sound to be played back. An even earlier 1857 recording yielded a sound that may have been a snatch of a human voice, but it is too short to identify it positively.

[edit] Phonograph theory

Charles Cros, a French scientist, produced a theory (April 18, 1877) concerning a phonograph, but he did not manufacture a working model. His theory was submitted to the French Academy of Sciences, and was read to the public in December 1877, by which time Edison had produced a working model. Cros and Edison apparently discovered their theories independently.

[edit] First phonograph

Thomas Alva Edison conceived the principle of recording and reproducing sound between May and July 1877 as a byproduct of his efforts to "play back" recorded telegraph messages and to automate speech sounds for transmission by telephone.^[4] He announced his invention of the first phonograph, a device for recording and replaying sound, on November 21, 1877, and he demonstrated the device for the first time on November 29 (it was patented on February 19, 1878 as US Patent 200,521). Edison's early phonographs recorded onto a tinfoil sheet phonograph cylinder using an up-down ("hill-and-dale") motion of the stylus.^[5] The tinfoil sheet was wrapped around a grooved cylinder, and the sound was recorded as indentations into the foil. Edison's early patents show that he also considered the idea that sound could be recorded as a spiral onto a disc, but Edison concentrated his efforts on cylinders, since the groove on the outside of a rotating cylinder provides a constant velocity to the stylus in the groove, which Edison considered more "scientifically correct". Edison's patent specified that the audio recording was embossed, and it was not until 1886 that vertically modulated engraved recordings using wax coated cylinders were patented by Chichester Bell and Charles Sumner Tainter. They named their version the Graphophone. Emile Berliner patented his Gramophone in 1887. The Gramophone involved a system of recording using a lateral (back and forth) movement of the stylus as it traced a spiral onto a zinc disc coated with a compound of beeswax in a solution of benzine. The zinc disc was immersed in a bath of chromic acid; this etched the groove into the disc where the stylus had removed the coating, after which the recording could be played.

In May 1889, the first "phonograph parlor" opened in San Francisco. Customers would sit at a desk where they could speak through a tube, and order a selection for one nickel. Through a separate tube connected to a cylinder phonograph in the room below, the selection would then be played. By the mid-1890s, most American cities had at least one phonograph parlor.

By 1890, record manufacturers had begun using a rudimentary duplication process to mass-produce their product. While the live performers recorded the master phonograph, up to ten tubes led to blank cylinders in other phonographs. Until this development, each record had to be custom-made. Before long, a more advanced pantograph-based process made it possible to simultaneously produce 150 copies of each record. However, as demand for certain records grew, popular artists still needed to re-record and re-re-record their songs. Reportedly, the medium's first major African-American star George Washington Johnson was obliged to perform his “The Laughing Coon” (or "Laughing Song") literally thousands of times in a studio during his recording career. Sometimes he would sing "The Laughing Coon" more than fifty times in a day, at twenty cents per rendition. (The average price of a single cylinder in the mid-1890s was about fifty cents.)

[edit] Thomas Edison's Account of inventing the Phonograph

Mr. Edison's own account of the invention of the phonograph is intensely interesting. "I was ex-perimenting," he says, "on an automatic method of recording telegraph messages on a disk of paper laid on a revolving platen, exactly the same as the disk talking-machine of to-day. The platen had a spiral groove on its surface, like the disk. Over this was placed a circular disk of paper; an electromagnet with the embossing point connected to an arm travelled over the disk; and any signals given through the magnets were embossed on the disk of paper. If this disk was removed from the machine and put on a similar machine provided with a contact point, the embossed record would cause the signals to be repeated into another wire. The ordinary speed of telegraphic signals is thirty-five to forty words a minute; but with this machine several hundred words were possible. "From my experiments on the telephone I knew of the power of a diaphragm to take up sound vibrations, as I had made a little toy which, when you recited loudly in the funnel, would work a pawl connected to the diaphragm; and this engaging a ratchet-wheel served to give continuous rotation to a pulley. This pulley was connected by a cord to a little paper toy representing a man sawing wood. Hence, if one shouted: ' Mary had a little lamb,' etc., the paper man would start sawing wood. I reached the conclusion that if I could record the movements of the diaphragm properly, I could cause such record to reproduce the original movements imparted to the diaphragm by the voice, and thus succeed in recording and reproducing the human voice. "Instead of using a disk I designed a little machine using a cylinder provided with grooves around the surface. Over this was to be placed tinfoil, which easily received and recorded the movements of the diaphragm. A sketch was made, and the piece-work price, $18, was marked on the sketch. I was in the habit of marking the price I would pay on each sketch. If the workman lost, I would pay his regular wages; if he made more than the wages, he kept it. The workman who got the sketch was John Kruesi. I didn't have much faith that it would work, expect- ing that I might possibly hear a word or so that would give hope of a future for the idea. Kruesi, when he had nearly finished it, asked what it was for. I told him I was going to record talking, and then have the machine talk back. He thought it absurd. However, it was finished, the foil was put on; I then shouted ' Mary had a little lamb,' etc. I adjusted the reproducer, and the machine reproduced it perfectly. I was never so taken aback in my life. Everybody was astonished. I was always afraid of things that worked the first time. Long experience proved that there were great drawbacks found generally before they could be got commercial; but here was something there was no doubt of."

[edit] Oldest surviving recordings

Frank Lambert's lead cylinder recording for an experimental talking clock is often identified as the oldest surviving playable sound recording,^[6] although the evidence advanced for its early date is controversial.^[7] The phonograph cylinder recordings of Handel's choral music made on June 29, 1888 at The Crystal Palace in London were thought to be the oldest known surviving musical recordings,^[8] until the recent playback by a group of American historians of a waveform of "Au Clair de la Lune", recorded on April 9, 1860.^[9] The 1860 phonautogram had not until then been played, as it was only an attempt to transcribe audio waves onto paper.

[edit] Disc versus cylinder as a recording medium

Disc recording is inherently neither better nor worse than cylinder recording in potential audio fidelity.

Recordings made on a cylinder remain at a constant linear velocity for the entirety of the recording, while those made on a disc have a higher linear velocity at the outer portion of the groove compared to the inner portion.

Edison's patented recording method recorded with vertical modulations in a groove. Berliner utilized a laterally modulated groove.

Though Edison's recording technology was better than Berliner's, there were commercial advantages to a disc system:

• The disc could be easily mass produced by molding and stamping, and required less storage space for a collection of recordings.
• The heavy cast-iron turntable acted as a flywheel and helped to maintain a consistent rotational velocity. The cylinder machine, lacking this greater rotational inertia, was susceptible to musical pitch fluctuations, and required more mechanical adjustment and maintenance to avoid this impairment.

Berliner successfully argued that his technology was different enough from Edison's that he did not need to pay royalties on it, which reduced his business expenses.

Through experimentation, in 1892 Berliner began commercial production of his disc records, and "gramophones" or "talking-machines". His "gramophone record" was the first disc record to be offered to the public. They were five inches (12.7 cm) in diameter and recorded on one side only. Seven-inch (17.5 cm) records followed in 1895. By 1901, ten-inch (25 cm) records were marketed by the Victor Talking Machine Company, and Berliner had sold his interests. By 1908, a majority of the public demanded double-sided disc recordings, and cylinders fell into disfavor. Edison felt the commercial pressure for disc records, and by 1912, though reluctant at first, his movement to disc records was in full swing.

From the mid-1890s until the early 1920s both phonograph cylinder and disc recordings and machines to play them on were widely mass-marketed and sold. The disc system gradually became more popular due to its cheaper price and better marketing by disc record companies. Edison ceased cylinder manufacture in the fall of 1929, and the history of disc and cylinder rivalry was concluded.

[edit] Dominance of the gramophone record

Berliner's lateral disc record was the ancestor of the 78 rpm, 45 rpm, 33⅓ rpm, and all other analogue disc records popular for use in sound recording through the 20th century. See gramophone record.

Christmas 1925 brought improved radio technology and radio sales, bringing many phonograph dealers to financial ruin. With efforts at improved audio fidelity, the big record companies succeeded in keeping business booming through the end of the decade, but the record sales plummeted during the Great Depression, with many companies merging or going out of business.

Booms in record sales returned after World War II as standards changed from 78s to vinyl long play records, which could contain an entire symphony and 45s which usually contained one hit popularized on the radio, plus another song on the back or "flip" side. An "extended play" version of the 45 was also available, designated 45 EP, which provided capacity for longer selections, or two regular-length songs per side.

By the 1960s, inexpensive portable record players and record changers which played stacks of records in wooden console cabinets were popular, usually with heavy and crude tone arms. Even drug stores stocked 45 rpm records at their front counters. Rock music played on 45s became the soundtrack to the 1960s as people bought the same songs that were played free of charge on the radio. Some record players were even tried in automobiles, but were quickly displaced by 8-track and cassette tapes.

High fidelity made great advances during the 1970s, as turntables became very precise instruments with belt or direct drive, jewel-balanced tonearms, some with electronically controlled linear tracking and magnetic cartridges. Some cartridges had frequency response above 30 kHz for use with CD-4 quadraphonic 4 channel sound. A high fidelity component system which cost under $1000 could do a very good job of reproducing very accurate frequency response across the human audible spectrum from 20 Hz to 20,000 Hz with a $200 turntable which would typically have less than .05% wow and flutter and very low rumble (low frequency noise). A well-maintained record would have very little surface noise, though it was difficult to keep records completely free from scratches, which produced popping noises. Another characteristic failure mode was groove lock, causing a section of music to repeat, separated by a popping noise. This was so common that a saying was coined: you sound like a broken record, referring to someone who is being annoyingly repetitious.

A novelty variation on the standard format was the use of multiple concentric spirals with different recordings. Thus when the record was played multiple times, different recordings would play seemingly at random.

Records themselves became an art form because of the large surface onto which graphics and books could be printed, and records could be molded into unusual shapes, colors, or with images (picture discs). The turntable remained a common element of home audio systems well after the introduction of other media such as audio tape and even the early years of the compact disc as a lower priced music format. However, even as the cost of producing CDs fell below that of records, CDs would remain a higher priced music format than cassettes or records. Thus, records were not uncommon in home audio systems into the early 1990s.

By the turn of the 21st century, the turntable had become a niche product, as the price of CD players, which reproduce music free from pops and scratches, fell far lower than high fidelity tape players or turntables. Nevertheless, there is some increase in interest as many big-box media stores stock turntables, as do professional DJ equipment stores. On the other hand, all but the most expensive stereo receivers now omit the phono input. The list price of first-run CDs remains above $15, while used records are very inexpensive, and some are rare and sought after. Some combination systems include turntables with a CD and radio in retro-styled cabinets, of much higher quality than the inexpensive record players common in the 1960s. Records also continue to be manufactured and sold today, albeit in very small quantities when compared to the disc phonograph's heyday.

[edit] Turntable technology

[edit] Turntable construction

Inexpensive record players typically used a flanged steel stamping for the turntable structure. A rubber disc would be secured to the top of the stamping to provide traction for the record, as well as a small amount of vibration isolation. The spindle bearing usually consisted of a bronze bushing. The flange on the stamping provided a convenient place to drive the turntable by means of an idler wheel (see below). While light and cheap to manufacture, these mechanisms had low inertia, making motor speed instabilities more pronounced.

Costlier turntables made from heavy aluminum castings have greater balanced mass and inertia, helping minimize vibration at the stylus, and maintaining constant speed without wow or flutter, even if the motor exhibits cogging effects. Like stamped steel turntables, they were topped with rubber. Due to the increased mass, they usually employed ball bearings or roller bearings in the spindle to reduce friction and noise. Most are belt or direct drive, but some use an idler wheel. A specific case was the Swiss "Lenco" drive, which possessed a very heavy turntable coupled via an idler wheel to a long, tapered motor drive shaft. This enabled stepless rotation or speed control on the drive. Because of this feature the Lenco became popular end of the 1950s with dancing schools, because the dancing instructor could lead the dancing exercises at different speeds.

[edit] Turntable drive systems

Many platters have a continuous series of strobe markings machined or printed around their edge to provide optical pulses to these speed-control systems. Viewing these markings in artificial light at mains frequency produces a stroboscopic effect, which can be used by the operator to verify rotational speed.

[edit] Idler-wheel drive system

Earlier designs used a rubberized idler-wheel drive system. However, wear and decomposition of the wheel, as well as the direct mechanical coupling to a vibrating motor, introduced low-frequency noise ("rumble") and speed variations ("wow and flutter") into the sound. These systems generally used a synchronous motor which ran at a speed synchronized to the frequency of the AC power supply. Portable record players typically used an inexpensive shaded-pole motor. At the end of the motor shaft there was a stepped driving capstan; to obtain different speeds, the rubber idler wheel was moved to contact different steps of this capstan. The idler was pinched against the bottom or inside edge of the platter to drive it.

Until the 1980s, the idler-wheel drive was the most common on turntables, except for higher-end audiophile models. However, even some higher-end turntables, such as the Lenco, Garrard "Zero" series and Dual turntables, used idler-wheel drive.

[edit] Belt drive system

Main article: Belt-drive turntable

In a belt drive turntable the motor is located under and to the side of the platter and is connected to the platter by an elastomeric belt. Belt drives brought improved motor and platter isolation compared to idler-wheel designs. Motor noise heard as low-frequency rumble was much reduced.

The design of the belt drive turntable allows for a less expensive motor than the direct-drive turntable to be used. Also, the elastomeric belt absorbs motor vibrations which would otherwise be picked up by the stylus. The Acoustical professional turntable (earlier marketed under Dutch "Jobo prof") of the 1960s however possessed an expensive German drive motor, the "Pabst Aussenläufer". As this motor name implied, the rotor was on the outside of the motor and acted as a flywheel ahead of the belt-driven turntable itself. In combination with a steel to nylon turntable bearing (with molybdeen sulfide material inside for lifelong lubrication) very low wow, flutter and rumble figures were achieved.

[edit] Direct drive system

Main article: Direct-drive turntable

Direct-drive turntables drive the platter directly without utilizing intermediate wheels, belts, or gears as part of a drive train. The platter functions as a motor armature. This requires good engineering, with advanced electronics for acceleration and speed control. Matsushita's Technics division introduced the first commercially successful direct drive platter, model SP10, in 1969 and it was replaced by the Technics SL-1200 turntable, in 1972. Its updated model, SL-1200MK2, released in 1978, had a stronger motor, a convenient pitch control slider for beatmatching and a stylus illuminator, which made it the long standing favourite among disc jockeys (see "Turntablism").

[edit] Pickup systems

Historically, most high-fidelity component systems (preamplifiers or receivers) that accepted input from a phonograph turntable had separate inputs for both ceramic and magnetic cartridges (typically labeled "CER" and "MAG"). One piece systems often had no additional phono inputs at all, regardless of type.

Most systems today, if they accept input from a turntable at all, are configured for use only with magnetic cartridges, with high end systems often having both MM and MC settings

[edit] Piezoelectric (crystal/ceramic) cartridges

Early electronic phonographs used a piezo-electric crystal for pickup, where the mechanical movement of the stylus in the groove generates a proportional electrical voltage by creating stress within a crystal (typically Rochelle salt). Crystal pickups are relatively robust, and produce a substantial signal level which requires only a modest amount of further amplification. The output is not very linear however, introducing unwanted distortion. It is difficult to make a crystal pickup suitable for quality stereo reproduction, as the stiff coupling between the crystal and the long styli used prevent close tracking of the needle to the groove modulations. This tends to increase wear on the record, and introduces more distortion. Another problem is with the nature of the crystal itself: it is hygroscopic and tries to absorb moisture from the air and dissolve in it. So it needed protection from the environment by embedding it in other materials, without hindering the movement of the pickup mechanism itself. After a number of years, the protective jelly often deteriorated or leaked from the cartridge case and the full unit needed replacement.

The next development was the ceramic cartridge, a piezoelectric device that used newer, and better, materials. These were more sensitive, and offered greater compliance, that is, lack of resistance to movement and so increased ability to follow the undulations of the groove without gross distorting or jumping out of the groove. Higher compliance meant lower tracking forces and reduced wear to both the disc and stylus. It also allowed ceramic stereo cartridges to be made.

During the 1950s to 1970s, ceramic cartridge became common in low quality phonographs, but better high-fidelity (or "hi-fi") systems used magnetic cartridges, and the availability of low cost magnetic cartridges from the 1970s onwards made ceramic cartridges obsolete for essentially all purposes. At the very end of the lifespan of ceramic cartridges, someone accidentally discovered that by terminating a specific ceramic mono cartridge (the Ronette TX88) not with the prescribed 47 kOhm resistance, but with approx. 10 kOhm, it could be connected to the moving magnet (MM) input too. The result, a much smoother frequency curve extended the lifetime for this popular and very cheap type.

Another popular ceramic stereo cartridge was the Audio Technica model AT66, which due to its price performance ratio was favoured by many as an alternative to more expensive magnetic cartridges.

[edit] Magnetic cartridges

Main article: magnetic cartridge

There are two common designs for magnetic cartridges, moving magnet (MM) and moving coil (MC) (originally called dynamic). Both operate on the same physics principle of electromagnetic induction. The moving magnet type was by far the most common and more robust of the two, though audiophiles often claim that the moving coil system yields higher fidelity sound.

In either type, the stylus itself, usually of diamond, is mounted on a tiny metal strut called a cantilever, which is suspended using a collar of highly compliant plastic. This gives the stylus the freedom to move in any direction. On the other end of the cantilever is mounted a tiny permanent magnet (moving magnet type) or a set of tiny wound coils (moving coil type). The magnet is close to a set of fixed pick-up coils, or the moving coils are held within a magnetic field generated by fixed permanent magnets. In either case, the movement of the stylus as it tracks the grooves of a record causes a fluctuating magnetic field which causes a small electrical current to be induced in the coils. This current closely follows the sound waveform cut into the record, and may be transmitted by wires to an electronic amplifier where it is processed and amplified in order to drive a loudspeaker. Depending upon the amplifier design, a phono-preamp may be necessary.

In most moving magnet designs, the stylus itself is detachable from the rest of the cartridge so it can easily be replaced. There are two primary types of cartridge mounts. The older type is attached using small screws to a headshell which then plugs into the tonearm, while the other is a standardized "P-mount" cartridge that plugs directly into the tonearm. Some mass market turntables use a proprietary integrated cartridge which cannot be upgraded.

An alternative design is the moving iron variation on moving magnet used by Grado, Stanton Magnetics, and the MMC cartridge of Bang & Olufsen. In these units, the magnet itself sits behind the four coils and magnetises the cores of all four coils. The moving iron cross at the other end of the coils varies the gaps between itself and each of these cores, according to its movements. These variations lead to voltage variations as described above.

Famous brands for magnetic cartridges were the MM-brands mentioned above: Grado, Stanton (681EE/EEE), B&O (MM-types for its two, non-compatible generations of parallel arm design), but also Shure (V15 MK I-IV), Audio Technica and Nagaoka. Ortofon, a very expensive Danish design focussed almost exclusively on moving coil technology and achieved leadership in this technology.

[edit] Optical readout

A few laser turntables have been announced (and some even appeared) which read the groove optically using a laser pickup. Since there is no physical contact with the record, no wear is incurred.

An alternative approach is to take a high-resolution photograph or scan of each side of the record and interpret the image of the grooves using computer software. An amateur attempt using a flatbed scanner lacked satisfactory fidelity^[10]. A professional system employed by the Library of Congress produces excellent quality^[11].

[edit] Styli

Main article: Magnetic cartridge

In the sound recording industry, a stylus is a phonograph or gramophone needle used to play back sound on gramophone records, as well as to record the sound indentations on the master record.

It is a crucial part of the phonograph, as it is the one part of the system that actually contacts the recorded disc and transfers its vibrations to the rest of the system. It is the part which also suffers the greatest wear. There are two desired qualities in a stylus: first, that it faithfully follows the contours of the recorded groove and transfers the vibration to the system, and second, that it does not damage the recorded disc.

Several technologies were used to record the sounds, beginning with wax cylinders. The harder the material used, the harder the stylus had to be. The latter stylus for vinyl records were made out of Sapphire or diamond. A specific case is the specofoc stylus type of B&O's moving magnet cartridge MMC 20CL, mostly used in parallel arm type B&O turntables in the 4002/6000 series. It uses a sapphire stem on which a diamond tip is fixed by a special adhesive. A stylus tip mass as low as 0.3 milligram is the result and full tracking only requires 1 gram of stylus force, reducing record wear even further. Maximum distortion (2nd harmonic) fell below 0.6%.

A wholly different side of this is the shape of needles and styli. The first needles were made of copper or steel and with the extreme forces exerted on them quickly worn out (exchanging them after 2 sides 78 rpm 25cm, or one side 30 cm were safe choices). Because of this wear, the exact form of the needle hardly received attention. Some needles were made with a bend so a stark backward sloping needle resulted, suggesting (but not offering) lower record and needle wear. Some people went to cactus needles and accepted loss in high frequency for longer record life. At the end of acoustic 78rpm, so-called longplay steel needles came on the market, for 10 sides of a normal 25 cm disk.

When sapphires were introduced for the 78 rpm disk and the LP, they were made by tapering a stem and polishing the end into sphere of around 70 and 25 Micrometer respectively. A sphere is not equal to the form of the cutting stylus and by the time diamond needles came to the market, a whole discussion was started on the effect of circular forms moving through a non-circular cut groove. It can be easily shown that vertical, so called "pinching" movements were a result and when the stereophonic LPs were introduced, unwanted vertical modulation was recognized as a problem. Also the needle started its life touching the groove on a very small surface, giving extra wear on the walls.

Another problem is in the tapering along a straight line, while the side of the groove is far from straight. Both problems were attacked together: by polishing the diamond in a certain way that it could be made doubly elliptic. 1) the side was made into one ellipse as seen from behind, meaning the groove touched along a short line and 2) the ellipse form was also polished as seen from above and curvature in the direction of the groove became much smaller than 25 Micrometer. e.g. 13 Micron. With this approach a number of irregularities were eliminated. Furthermore, the angle of the stylus which used to be always sloping backwards, was changed into the forward direction, in line with the slope the original cutting stylus possessed. These styli were expensive to produce, but purists accepted these costs all the more, because by now stylus life was much higher than before.

The last development in stylus form came about by the attention to CD-4 quadraphonic sound with cartridges like Nagaoka capable of playback on frequencies up to 70 kHz. The so-called Shibata stylus was invented in Japan and marketed as an extra on some expensive cartridges, despite the fact that CD4 disk technology itself quickly disappeared. Yet another needle form was advocated by a certain Mr. A.J. van den Hul. His "van den Hul" styli were another, very expensive extra, offered on request for cartridges such as Shure V15 (types I-IV), Stanton (681EE and EEE) and Ortofon's MM-line. Probably to evade patent rights, B&O designed its own "contact line", non-elliptical MMC 20CL stylus.

To get the feel for the costs of these developments: for the price of a semi-professional turntable in the 1960s (€175,- equivalent), high-end ceramic cartridge included, one could just buy this MMC 20CL B&O cartridge end of the 70's. The 4002 B&O turntable (with parallel arm) was €1000,- equivalent in the 1980s. For van den Hul styli, historical price levels are hard to find, but Ortofon elements alone started at €300,- and the van den Hul styli tended to double the high-end cartridge prices (of €450,-) up to €900,-. More recently, phonograph cartridges have ranged in price from about US$50 for a basic moving-magnet unit with elliptical stylus to stratospheric levels for audiophile moving-coil units with exotic stylus forms. For example, the May 1999 issue of Stereophile magazine shows a price of US$5000 (€3500,-) for the van den Hul Black Beauty phono cartridge.

[edit] Equalization

Early "mechanical" gramophones used the stylus to vibrate a diaphragm radiating through a horn. Several serious problems resulted from this:

• The maximum sound level achievable was quite limited, being limited to the physical amplification effects of the horn,
• The energy needed to generate such sound levels as were obtainable had to come directly from the stylus tracing the groove. This required very high tracking forces that rapidly wore out both the stylus and the record.
• Because bass sounds have a higher amplitude than high frequency sounds (for the same perceived loudness), the space taken in the groove by low frequency sounds needed to be large (limiting playback time per side of the record) to accommodate the bass notes, yet the high frequencies required only tiny variations in the groove, which were easily affected by noise from irregularities (wear, contaminates, etc) in the disk itself.

The introduction of electronic amplification allowed these issues to be addressed. Records are made with boosted high frequencies and/or reduced low frequencies. This reduces the effect of background noise, including clicks or pops, and also conserves the amount of physical space needed for each groove, by reducing the size of the low-frequency undulations.

During playback, the high frequencies must be rescaled to their original, flat frequency response—known as "equalization"—as well as being amplified. A phono input of an amplifier incorporates such equalization as well as amplification to suit the very low level output from a modern cartridge. Most hi-fi amplifiers made between the 1950s and the 1990s and virtually all DJ mixers are so equipped.

The widespread adoption of digital music formats, such as CD or satellite radio, has displaced phonograph records and resulted in phono inputs being omitted in most modern amplifiers. Some newer turntables include built-in preamplifiers to produce line-level outputs. Inexpensive and moderate performance discrete phono preamplifiers with RIAA equalization are available, while high-end audiophile units costing thousands of dollars continue to be available in very small numbers.

Since the late 1950s, almost all phono input stages have used the RIAA equalization standard. Before settling on that standard, there were many different equalizations in use, including EMI, HMV, Columbia, Decca FFRR, NAB, Ortho, BBC transcription, etc. Recordings made using these other equalization schemes will typically sound odd if they are played through a RIAA-equalized preamplifier. High-performance (so-called "multicurve disc") preamps, which include multiple, selectable equalizations, are no longer commonly available. However, some vintage preamps, such as the LEAK varislope series, are still obtainable and can be refurbished. Newer preamplifiers like the Esoteric Sound Re-Equalizer or the K-A-B MK2 Vintage Signal Processor are also available.^[12] These kinds of adjustable phono equalizers are used by consumers wishing to play vintage record collections (often the only available recordings of musicians of the time) with the equalization used to make them.

[edit] Arm systems

The tone arm (or tonearm) holds the pickup cartridge over the groove, the stylus tracking the groove with the desired force to give the optimal compromise between good tracking and minimizing wear of the stylus and record groove. At its simplest, a tone arm is a pivoted lever, free to move in two axes (vertical and horizontal) with a counterbalance to maintain tracking pressure.

However, the requirements of high-fidelity reproduction place more demands upon the arm design:

• The tone arm must track the groove without distorting the stylus assembly, so an ideal arm would have no mass, with bearings requiring zero force to move it.
• The arm should not oscillate following a displacement, so it should either be both light and very stiff, or suitably damped.
• The arm must not resonate with vibrations induced by the stylus or from the turntable motor or plinth, so it must likewise be heavy enough not to resonate at those frequencies, or it must be damped to absorb vibrations.

These demands are contradictory and impossible to realize (massless arms and zero-friction bearings do not exist in the real world), and consequently all tone arm designs are engineering compromises. Solutions vary, but all modern tonearms are at least relatively lightweight and stiff constructions with precision, very low friction pivot bearings in both vertical and horizontal axes. Most arms are made from some kind of alloy (the cheapest being aluminum), but one manufacturer tried balsa wood, the lightest wood known to man, others tried carbon fibers. The latter materials favour a straight arm design, while alloy arms are easier for S-type arms.

Prices vary largely: the well known and extremely popular high-end S-type SME-arm of the 1970-1980 era not only possessed a complicated design, but was also very costly. On the other hand a very cheap arm was made by the now defunct Dutch Jobo/Acoustical firm. This "All balance" arm was only €30,- equivalent. It was used by both the official Dutch radio studios of the NOS, as well as by the pirate radio station Veronica. Live disk jockeys lived on this radioship, meaning that the arm had to withstand sudden ship movements. Anecdotic information tells us, that this cheap arm was the only one capable of keeping the needle firmly in the groove, even during heavy storms at sea.

Basic arm design has changed relatively little. S-type tonearms can be found on even the early 1925 Victor Orthophonic phonograph. Though early electrical pickup tonearms were light, their full weight rested on the record. Through to the crystal pickup, this was required to create sufficient tracking force to follow the grooves adequately with relatively stiff styli. Record wear was high. With better technologies (magnetic cartridge), far-smaller tracking forces became possible, and the balanced arm came into use. Most use a counterweight to offset the weight of the arm, cartridge included. A separate spring or small weight provided for finetuning in tracking force. Often, a calibrated dial on the weight provides quick adjustment of stylus force. Stylus forces of 10 to 20 mN (1 to 2 "grams-force", frequently mis-labeled by manufacturers as simply "grams") are typical for modern high-fidelity turntables, while forces of up to 50 mN (5 "grams-force") are common for DJ use. Stanton cartridges of the 681EE(E) series had a small brush attached to it, the weight of which required compensation of the tracking force value.

Tonearms are prone to two types of tracking errors that affect the sound. As the tonearm tracks the groove, the stylus drags tangent to the disc surface and resistance by the arm creates a horizontal skating force towards the center of the disc. Modern arms provide an anti-skating mechanism, using springs, hanging weights, or magnets to offset this force, making the net horizontal force near zero. The second error occurs as the arm sweeps in an arc across the disc, causing the angle between the cartridge head and groove to change slightly. A change in angle, albeit small, will have a detrimental effect (especially in stereo) by creating different forces on the two groove walls. Making the arm longer to reduce this angle is a partial solution, but less than ideal, because longer arms weigh more, and because even a long arm won't be long enough since only an infinitely long arm would reduce this error to zero. Some arms (such as the Garrard "Zero" series) have been manufactured with a parallelogram arrangement which pivots the cartridge head on the arm to maintain a constant angle.

If the arm is not pivoted, but instead travels horizontally along a radius of the disc, there is no skating force and no cartridge angle error. Such arms are driven along a linear track using an electronic servomechanism, or a precise mechanical adjustment (the Rabco arm) to position it properly. Rabco developed the first zero tracking error tonearm, followed by Bang & Olufsen with its Beogram 4000 model in 1972. A later development was made by Revox, a Swiss company more widely known for his high end reel to reel tape recorders: they designed a parallel movement using a very short arm moving sideways across the disk under the influence of a special drive motor. The mechanism had to be turned over the disk after its placement and turned back after playing the disk. This was contrary to the B&O design which automatically returned its parallel arm after playing and even detected whether a smaller (and therefor 45 rpm) disk was present or a larger (and therefor 33 rpm) disk. Only for the by then rare smaller 33rpm disks this system needed a manual speed override.

Early Edison phonographs had used similarly horizontal spring-powered drives to carry the stylus across the record at a pre-determined rate. In practice, the linear tracking system is not widely used today due to its complexity and related expense. However, some of the most sophisticated and expensive systems still employ this technique. It is nearly ideal, as the stylus replicates the motion of the recording lathe when the master recording was cut.

                             Phonograph in the 21st century 

      Turntables continue to be manufactured and sold into the 21st century, although in small numbers. While there are many audiophiles who still prefer vinyl records over digital music sources (primarily [compact disc) for their perceived fidelity, they represent an enthusiastic minority of listeners. The quality of the available record players, tonearms, and cartridges has continued to improve, despite a diminishing market. Thus, the turntable remains the preferred sound source in some high end audio systems. 

     Updated versions of the 1970s era [Technics SL-1200] have remained an industry standard for DJs to the present day. Turntables and vinyl records remain popular in mixing (mostly dance-oriented) forms of electronic music, where they allow great latitude for physical manipulation of the music by the DJ. 

    In hip hop music, the turntable is used as a musical instrument. Manipulation of a record as part of the music rather than for normal playback or mixing, is called turntablism.  The basis of turntablism and its best known technique is scratching, pioneered by Grand Wizard Theodore. It was not until Herbie Hancock's "Rockit" in 1983 that the turntablism movement was recognized in popular music outside of a hip hop context. .

The laser turntable, which uses a laser as the pickup instead of a stylus in physical contact with the disk, was conceived of in the late 1980s, although early prototypes were not of usable audio quality. Practical laser turntables are now being manufactured by ELPJ. They are favoured by record libraries and some audiophiles since they eliminate physical wear completely. Experimentation is in progress in retrieving the audio from old records by scanning the disc and analysing the scanned image, rather than using any sort of turntable.

Notable turntables include: the Linn Sondek LP12, the Sota Cosmos, Roksan Audio Roksan Xerxes, the Immedia RPM-2, the VPI TNT, Michell Orbe SE and the SME Models 20 and 30.

     Although largely replaced since the introduction of the compact disc in 1982, record albums still sell in small numbers and are available through numerous sources. Many audiophiles believe that all-analogue recordings made using a traditional tape recorder, simple microphone arrays and few overdubs have a more natural sound than digital recordings.

[edit] Direct vs belt drive

Although most high-quality turntables use a rubber belt to drive the rotating platter from an electric motor, the Rockport Sirius, for example, uses a linear induction motor with no physical connection to the platter. The direct-drive turntable, for example, the abovementioned Technics SL-1200, became popular in the late 1970s.

Many turntables, such as the Rega Planar series, use a fixed plinth with the motor and bearing attached to the same flat surface, usually constructed of wood, metal or acrylic, others use a "suspended sub-chassis" design, where the platform allows the stylus to track accurately relative to the surface of the record whilst being protected from external vibrations. The platter, sub-chassis, armboard and tonearm mechanically form a closed loop, and sit on top of dampers.

The evaluation of the "best" turntable design is very subjective and often based more on listening experience. Technical measurement is fraught with difficulties: first there is the difficulty of measuring small parameters, secondly there is disagreement about relevant parameters to measure.

Audiophile grade turntables start at a few hundred dollars and range upwards of $10,000, depending on the complexity and quality of design and manufacture. The common view would be that there are diminishing returns with an increase in price - a turntable costing $1,000 would not sound significantly better than a turntable costing $500; nevertheless, there exists a large choice of expensive turntables although the popularity of the vinyl replay medium has been surpassed for some time.

[edit] See also

• Audio signal processing
• Phonograph manufacturers
• Record changer
• Sound reproduction
• Gramophone record
• RIAA equalization

[edit] References

[edit] External links

• André's Talking Machines
• Mario Frazzetto's Phonograph and Gramophone Gallery.
• The Cylinder Archive
• Classical record collectingat Vintage Audio Forum
• The 1888 Crystal Palace Recordings
• Invention of the Phonograph
• The Birth of the Recording Industry
• The Phonograph vs. the Gramophone
• Phonograph technology in 1958
• Record scanning - Ofer Springer
• musicangle
• Swiss Phonograph Collection
• Stereo |411 Turntable Forum - Talk about turntables and other high end sources
• Cylinder Preservation & Digitization Project — Over 6,000 cylinder recordings held by the Department of Special Collections, University of California, Santa Barbara, free for download or streamed online.
• Say What? – Essay on phonograph technology and intellectual property law
• Vinyl Records Still Live! - site dedicated to preserving vinyl records
• San Francisco State University Museum of Anthropology
• Listen to early recordings on the Edison Phonograph
• Re-invention of the Phonograph

v • d • e Grooved track audio Machines Phonograph/gramophone · Direct-drive turntable · Belt-drive turntable · Jukebox Formats Phonograph cylinder · Gramophone record

v • d • e Audio formats Analog Phonautograph (1857) · Phonograph cylinder (1877) · Gramophone record (1895) · Wire recording (1898) · Reel-to-reel tape (1940s) · SoundScriber (1945) · Gray Audograph (1945) · Dictabelt (1947) · LP record (1948) · 45 rpm record (1949) · RCA tape cartridge (1958) · Fidelipac (1959) · Stereo-Pak (1962) · Compact Cassette (1963) · Stereo 8 (1964) · PlayTape (1966) · Mini Cassette (1967) · Microcassette (1969) · Steno-Cassette (1971) · Elcaset (1976) · Cassette single (1982) · Picocassette (1985) Digital Soundstream (1976) · 3M (1979) · X80/ProDigi (1980) · DASH (1982) · Compact Disc (1982) · Digital Audio Tape (1987) · ADAT (1991) · MiniDisc (1991) · Digital Compact Cassette (1992) · Extended Resolution Compact Disc (1995) · High Definition Compatible Digital (1995) · 5.1 Music Disc (1997) · Super Audio CD (1999) · DVD-Audio (2000) · K2 High Definition (2007) · USB flash drive (as audio format, 2008)