In 1885, when the Volta Associates were sure that they had a number of practical inventions, they filed patent applications and began to seek out investors. The Volta Graphophone Company of Alexandria, Virginia, was created on January 6, 1886 and incorporated on February 3, 1886. It was formed to control the patents and to handle the commercial development of their sound recording and reproduction inventions, one of which became the first Dictaphone.
After the Volta Associates gave several demonstrations in the City of Washington, businessmen from Philadelphia created the American Graphophone Company on March 28, 1887, in order to produce and sell the machines for the budding phonograph marketplace. The Volta Graphophone Company then merged with American Graphophone, which itself later evolved into Columbia Records.
Shortly after American Graphophone's creation, Jesse H. Lippincott used nearly $1 million of an inheritance to gain control of it, as well as the rights to the Graphophone and the Bell and Tainter patents. Not long later Lippincott purchased the Edison Speaking Phonograph Company. He then created the North American Phonograph Company to consolidate the national sales rights of both the Graphophone and the Edison Speaking Phonograph. In the early 1890s Lippincott fell victim to the unit's mechanical problems and also to resistance from stenographers.
A coin-operated version of the Graphophone, U.S. Patent 506,348, was developed by Tainter in 1893 to compete with nickel-in-the-slot entertainment phonograph U.S. Patent 428,750 demonstrated in 1889 by Louis T. Glass, manager of the Pacific Phonograph Company.
The work of the Volta Associates laid the foundation for the successful use of dictating machines in business, because their wax recording process was practical and their machines were durable. But it would take several more years and the renewed efforts of Edison and the further improvements of Emile Berliner and many others, before the recording industry became a major factor in home entertainment.
Discs are not inherently better than cylinders at providing audio fidelity. Rather, the advantages of the format are seen in the manufacturing process: discs can be stamped; cylinders could not be until 1901–1902 when the gold moulding process was introduced by Edison.
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 disc 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,[clarification needed] there were commercial advantages to a disc system since the disc could be easily mass-produced by molding and stamping and it required less storage space for a collection of recordings.
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". 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. Also in 1895 Berliner replaced the hard rubber used to make the discs with a shellac compound. Berliner's early records had very poor sound quality, however. Work by Eldridge R. Johnson eventually improved the sound fidelity to a point where it was as good as the cylinder. By late 1901, ten-inch (25 cm) records were marketed by Johnson and Berliner's Victor Talking Machine Company, and Berliner had sold his interests. In 1904, discs were first pressed with music on both sides and capable of around seven minutes total playing time, as opposed to the cylinder's typical duration on two minutes at that time. As a result of this and the fragility of wax cylinders in transit and storage, cylinders sales declined. Edison felt the increasing commercial pressure for disc records, and by 1912, though reluctant at first, his production of disc records was in full swing. This was the Edison Disc Record. Nevertheless, he continued to manufacture cylinders until 1929 and was last to withdraw from that market.
From the mid-1890s until World War I, both phonograph cylinder and disc recordings and machines to play them on were widely mass-marketed and sold. The disc system superseded the cylinder in Europe by 1906 when both Columbia and Pathe withdrew from that market. By 1913, Edison was the only company still producing cylinders in the USA although in Great Britain small manufacturers pressed on until 1922.
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. See gramophone record.
The 1920s brought improved radio technology. Radio sales increased, bringing many phonograph dealers to near 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.
Record sales picked up appreciably by the late 30s and early 40s, with greater improvements in fidelity and more money to be spent. By this time home phonographs had become much more common, though it wasn't until the 1940s that console radio/phono set-ups with automatic record changers became more common.
In the 1930s, vinyl (originally known as vinylite) was introduced as a record material for radio transcription discs, and for radio commercials. At that time, virtually no discs for home use were made from this material. Vinyl was used for the popular 78-rpm V-discs issued to US soldiers during World War II. This significantly reduced breakage during transport. The first commercial vinylite record was the set of five 12" discs "Prince Igor" (Asch Records album S-800, dubbed from Soviet masters in 1945). Victor began selling some home-use vinyl 78s in late 1945; but most 78s were made of a shellac compound until the 78-rpm format was completely phased out. (Shellac records were heavier and more brittle.) 33s and 45s were, however, made exclusively of vinyl, with the exception of some 45s manufactured out of polystyrene.
Booms in record sales returned after the Second World War, as industry standards changed from 78s to vinyl, long-playing records (commonly called record albums), which could contain an entire symphony, and 45s which usually contained one hit song popularized on the radio – thus the term "single" record – 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 musical selections, or for two regular-length songs per side.
Shortcomings include surface noise caused by dirt or abrasions (scratches) and failure caused by deep surface scratches causing skipping of the stylus forward and missing a section, or groove lock, causing a section to repeat, usually punctuated by a popping noise. This was so common that the phrase: "you sound like a broken record,” was coined, referring to someone who is being annoyingly repetitious.
In 1955, Philco developed and produced the world's first all-transistor phonograph models TPA-1 and TPA-2, which were announced in the June 28, 1955 edition of the Wall Street Journal. Philco started to sell these all-transistor phonographs in the fall of 1955, for the price of $59.95. The October 1955 issue of Radio & Television News magazine (page 41), had a full page detailed article on Philco's new consumer product. The all-transistor portable phonograph TPA-1 and TPA-2 models played only 45rpm records and used four 1.5 volt "D" batteries for their power supply. The "TPA" stands for "Transistor Phonograph Amplifier". Their circuitry used three Philco germanium PNP alloy-fused junction audio frequency transistors. After the 1956 season had ended, Philco decided to discontinue both models, for transistors were too expensive compared to vacuum tubes, but by 1961 a $49.95 ($427.36 in 2019) portable, battery-powered radio-phonograph with seven transistors was available.
By the 1960s, cheaper portable record players and record changers which played stacks of records in wooden console cabinets were popular, usually with heavy and crude tonearms in the portables. The consoles were often equipped with better quality pick-up cartridges. Even pharmacies 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.
The fidelity of sound reproduction 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 well under $1,000 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 0.05% wow and flutter and very low rumble (low frequency noise). A well-maintained record would have very little surface noise.
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. These were often utilized in talking toys and games.
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 though the cost of producing CDs fell below that of records, CDs remained a higher-priced music format than either 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 of pops and scratches, fell far lower than high-fidelity tape players or turntables. Nevertheless, there is some increase in interest; many big-box media stores carry turntables, as do professional DJ equipment stores. Most low-end and mid-range amplifiers omit the phono input; but on the other hand, low-end turntables with built-in phono pre-amplifiers are widely available. Some combination systems include a basic turntable, a CD player, a cassette deck. and a radio, in a retro-styled cabinet. Records also continue to be manufactured and sold today, albeit in smaller quantities than in the disc phonograph's heyday.
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 aluminium 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. Because of 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 in the late 1950s with dancing schools, because the dancing instructor could lead the dancing exercises at different speeds.
By the early 1980s, some companies started producing very inexpensive turntables that displaced the products of companies like BSR. Commonly found in "all-in-one" stereos from assorted far-east manufacturers, they used a thin plastic table set in a plastic plinth, no mats, belt drive, weak motors, and often, lightweight plastic tonearms with no counterweight. Most used sapphire pickups housed in ceramic cartridges, and they lacked several features of earlier units, such as auto-start and record-stacking. While not as common now that turntables are absent from the cheap "all-in-one" units, this type of turntable has made a strong resurgence in nostalgia-marketed record players.
From the earliest phonograph designs, many of which were powered by spring-wound mechanisms, a speed governor was essential. Most of these employed some type of flywheel-friction disc to control the speed of the rotating cylinder or turntable; as the speed increased, centrifugal force caused a brake—often a felt pad—to rub against a smooth metal surface, slowing rotation. Electrically powered turntables, whose rotational speed was governed by other means, eventually made their mechanical counterparts obsolete. The mechanical governor was, however, still employed in some toy phonographs (such as those found in talking dolls) until they were replaced by digital sound generators in the late 20th century.
Many modern players have platters with a continuous series of strobe markings machined or printed around their edge. Viewing these markings in artificial light at mains frequency produces a stroboscopic effect, which can be used to verify proper rotational speed. Additionally, the edge of the turntable can contain magnetic markings to provide feedback pulses to an electronic speed-control 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 1970s, 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, EMT, and Dual turntables, used idler-wheel drive.
Belt drives brought improved motor and platter isolation compared to idler-wheel designs. Motor noise, generally heard as low-frequency rumble, is greatly reduced. The design of the belt drive turntable allows for a less expensive motor than the direct-drive turntable to be used. The elastomeric belt absorbs motor vibrations and noise which could otherwise be picked up by the stylus. It also absorbs small, fast speed variations, caused by "cogging", which in other designs are heard as "flutter."
The "Acoustical professional" turntable (earlier marketed under Dutch "Jobo prof") of the 1960s however possessed an expensive German drive motor, the "Pabst Aussenläufer" ("Pabst outrunner"). 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 molybdenum disulfide inside for lifelong lubrication) very low wow, flutter and rumble figures were achieved.
Direct-drive turntables drive the platter directly without utilizing intermediate wheels, belts, or gears as part of a drive train. 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, which was joined 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"). By the beginnings of the 80s, lowering of costs in microcontroller electronics made direct drive turntables more affordable.
Audiophile grade turntables start at a few hundred dollars and range upwards of $100,000, depending on the complexity and quality of design and manufacture. The common view is 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.
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. In a perfect world:
These demands are contradictory and impossible to realize (massless arms and zero-friction bearings do not exist in the real world), so tone arm designs require 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 the vertical and horizontal axes. Most arms are made from some kind of alloy (the cheapest being aluminium), but some manufacturers use balsa wood, while others use carbon fiber or graphite. The latter materials favor a straight arm design; alloys' properties lend themselves to S-type arms.
The tone arm got its name before the age of electronics. It originally served to conduct actual sound waves from a purely mechanical "pickup" called a sound box or reproducer to a so-described "amplifying" horn. The earliest electronic record players, introduced at the end of 1925, had massive electromagnetic pickups that contained a horseshoe magnet, used disposable steel needles, and weighed several ounces. Their full weight rested on the record, providing ample tracking force to overcome their low compliance but causing rapid record wear. The tone arms were rudimentary and remained so even after lighter crystal pickups appeared about ten years later. When fine-grooved vinyl records were introduced in the late 1940s, still smaller and lighter crystal (later, ceramic) cartridges with semi-permanent jewel styluses became standard. In the mid-1950s these were joined by a new generation of magnetic cartridges that bore little resemblance to their crude ancestors. Far smaller tracking forces became possible and the balanced arm came into use.
Prices varied widely. The well-known and extremely popular high-end S-type SME arm of the 1970–1980 era not only had a complicated design, it was also very costly. On the other hand, even some cheaper arms could be of professional quality: the "All Balance" arm, made by the now-defunct Dutch company Acoustical, was only €30 [equivalent]. It was used during that period by all official radio stations in the Dutch Broadcast studio facilities of the NOS, as well as by the pirate radio station Veronica. Playing records from a boat in international waters, the arm had to withstand sudden ship movements. Anecdotes indicate this low-cost arm was the only one capable of keeping the needle firmly in the groove during heavy storms at sea.
Quality arms employ an adjustable counterweight to offset the mass of the arm and various cartridges and headshells. On this counterweight, a calibrated dial enables easy adjustment of stylus force. After perfectly balancing the arm, the dial itself is "zeroed"; the stylus force can then be dialed in by screwing the counterweight towards the fulcrum. (Sometimes a separate spring or smaller weight provides fine tuning.) Stylus forces of 10 to 20 mN (1 to 2 grams-force) are typical for modern consumer turntables, while forces of up to 50 mN (5 grams) are common for the tougher environmental demands of party deejaying or turntablism. Of special adjustment consideration, Stanton cartridges of the 681EE(E) series [and others like them] feature a small record brush ahead of the cartridge. The upforce of this brush, and its added drag require compensation of both tracking force (add 1 gram) and anti-skating adjustment values (see next paragraph for description).
Even on a perfectly flat LP, tonearms are prone to two types of tracking errors that affect the sound. As the tonearm tracks the groove, the stylus exerts a frictional force tangent to the arc of the groove, and since this force does not intersect the tone arm pivot, a clockwise rotational force (moment) occurs and a reaction skating force is exerted on the stylus by the record groove wall away from center of the disc. Modern arms provide an anti-skate mechanism, using springs, hanging weights, or magnets to produce an offsetting counter-clockwise force at the pivot, making the net lateral force on the groove walls 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 with stereo recordings) by creating different forces on the two groove walls, as well as a slight timing shift between left/right channels. Making the arm longer to reduce this angle is a partial solution, but less than ideal. A longer arm weighs more, and only an infinitely long [pivoted] arm would reduce the error to zero. Some designs (Burne-Jones, and Garrard "Zero" series) use dual arms in a parallelogram arrangement, pivoting the cartridge head to maintain a constant angle as it moves across the record. Unfortunately this "solution" creates more problems than it solves, compromising rigidity and creating sources of unwanted noise.
The pivoted arm produces yet another problem which is unlikely to be significant to the audiophile, though. As the master was originally cut in a linear motion from the edge towards the center, but the stylus on the pivoted arm always draws an arc, this causes a timing drift that is most significant when digitizing music and beat mapping the data for synchronization with other songs in a DAW or DJ software unless the software allows building a non-linear beat map. As the contact point of the stylus on the record wanders farther from the linear path between the starting point and center hole, the tempo and pitch tend to decrease towards the middle of the record, until the arc reaches its apex. After that the tempo and pitch increase towards the end as the contact point comes closer to the linear path again. Because the surface speed of the record is lower at the end, the relative speed error from the same absolute distance error is higher at the end, and the increase in tempo is more notable towards the end than the decrease towards the middle. This can be somewhat reduced by a curved arm pivoted so that the end point of the arc stays farther from the linear path than the starting point, or by a long straight arm that pivots perpendicularly to the linear path in the middle of the record. However the tempo droop at the middle can only be completely avoided by a linear tracking arm.
If the arm is not pivoted, but instead carries the stylus along a radius of the disc, there is no skating force and little to no cartridge angle error. Such arms are known as linear tracking or tangential arms. These are driven along a track by various means, from strings and pulleys, to worm gears or electromagnets. The cartridge's position is usually regulated by an electronic servomechanism or mechanical interface, moving the stylus properly over the groove as the record plays, or for song selection.
There are long-armed and short-armed linear arm designs. On a perfectly flat record a short arm will do, but once the record is even slightly warped, a short arm will be troublesome. Any vertical motion of the record surface at the stylus contact point will cause the stylus to considerably move longitudinally in the groove. This will cause the stylus to ride non-tangentially in the groove and cause a stereo phase error as well as pitch error every time the stylus rides over the warp. Also the arm track can come into touch with the record. A long arm will not completely eliminate this problem but will tolerate warped records much better.
Early developments in linear turntables were from Rek-O-Kut (portable lathe/phonograph) and Ortho-Sonic in the 1950s, and Acoustical in the early 1960s. These were eclipsed by more successful implementations of the concept from the late 1960s through the early 1980s. Of note are Rabco's SL-8, followed by Bang & Olufsen with its Beogram 4000 model in 1972. These models positioned the track outside the platter's edge, as did turntables by Harman Kardon, Mitsubishi, Pioneer, Yamaha, Sony, etc. A 1970s design from Revox harkened back to the 1950s attempts (and, record lathes), positioning the track directly over the record. An enclosed bridge-like assembly is swung into place from the platter's right edge to its middle. Once in place, a short tonearm under this "bridge" plays the record, driven across laterally by a motor. The Sony PS-F5/F9 (1983) uses a similar, miniaturized design, and can operate in a vertical or horizontal orientation. The Technics SL-10, introduced in 1981, was the first direct drive linear tracking turntable, and placed the track and arm on the underside of the rear-hinged dust cover, to fold down over the record, similar to the SL-Q6 pictured.
The earliest Edison phonographs used horizontal, spring-powered drives to carry the stylus across the recording at a pre-determined rate. But, historically as a whole, the linear tracking systems never gained wide acceptance, due largely to their complexity and associated production/development costs. The resources it takes to produce one incredible linear turntable could produce several excellent ones. Some of the most sophisticated and expensive tonearms and turntable units ever made are linear trackers, from companies such as Rockport and Clearaudio. In theory, it seems nearly ideal; a stylus replicating the motion of the recording lathe used to cut the "master" record could result in minimal wear and maximum sound reproduction. In practice, in vinyl's heyday it was generally too much too late.
Since the early 1980s, an elegant solution has been the near-frictionless air bearing linear arm that requires no tracking drive mechanism other than the record groove. This provides a similar benefit as the electronic linear tonearm without the complexity and necessity of servo-motor correction for tracking error. In this case the trade-off is the introduction of pneumatics in the form of audible pumps and tubing. A more elegant solution is the mechanically driven low-friction design, also driven by the groove. Examples include Souther Engineering (U.S.A.), Clearaudio (Germany), and Aura (Czech Republic). This design places an exceeding demand upon precision engineering due to the lack of pneumatics.
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. Manufacturers of high-end systems often have in-built moving coil amplifier circuitry, or outboard head-amplifiers supporting either moving magnet or moving coil cartridges that can be plugged into the line stage.
Additionally, cartridges may contain styli or needles that can be separated according to their tip: Spherical styli, and elliptical styli. Spherical styli have their tip shaped like one half of a sphere, and elliptical styli have their tip shaped like one end of an ellipse. Spherical styli preserve more of the groove of the record than elliptical styli, while elliptical styli offer higher sound quality.
Early electronic phonographs used a piezo-electric crystal for pickup (though the earliest electronic phonographs used crude magnetic pick-ups), 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 stylus prevents close tracking of the needle to the groove modulations. This tends to increase wear on the record, and introduces more distortion. Another problem is the hygroscopic nature of the crystal itself: it absorbs moisture from the air and may dissolve. The crystal was protected 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.
Between the 1950s and 1970s, ceramic cartridges became common in low-quality phonographs, but better high-fidelity (or "hi-fi") systems used magnetic cartridges. The availability of low-cost magnetic cartridges from the 1970s onwards made ceramic cartridges obsolete for essentially all purposes. At the seeming end of the market lifespan of ceramic cartridges, someone accidentally discovered that by terminating a specific ceramic mono cartridge (the Ronette TX88) not with the prescribed 47 kΩ resistance, but with approx. 10 kΩ, 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.
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 electric 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-preamplifier 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 three primary types of cartridge mounts. The most common type is attached using two small screws to a headshell that then plugs into the tonearm, while another is a standardized "P-mount" or "T4P" cartridge (invented by Technics in 1980 and adopted by other manufacturers) that plugs directly into the tonearm. Many P-mount cartridges come with adapters to allow them to be mounted to a headshell. The third type is used mainly in cartridges designed for DJ use and it has a standard round headshell connector. Some mass market turntables use a proprietary integrated cartridge that cannot be upgraded.
An alternative design is the moving iron variation on moving magnet used by ADC, Grado, Stanton/Pickering 681 series, Ortofon OM and VMS series, 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 are: Grado, Stanton/Pickering (681EE/EEE), B&O (MM types for its two, non-compatible generations of parallel arm design), Shure (V15 Type I to V), Audio-Technica, Nagaoka, Dynavector, Koetsu, Ortofon, Technics, Denon and ADC.
Strain gauge or "semiconductor" cartridges do not generate a voltage, but act like a variable resistor, whose resistance directly depends on the movement of the stylus. Thus, the cartridge "modulates" an external voltage supplied by the (special) preamplifier. These pickups were marketed by Euphonics, Sao Win, and Panasonic/Technics, amongst others.
The main advantages (compared to magnetic carts are):
The main disadvantage is the need of a special preamplifier that supplies a steady current (typically 5mA) to the semiconductor elements and handles a special equalization than the one needed for magnetic cartridges.
A high-end strain-gauge cartridge is currently sold by an audiophile company, with special preamplifiers available.
Electrostatic cartridges were marketed by Stax in the 1950 and 1960 years. They needed individual operating electronics or preamplifiers.
A few specialist laser turntables read the groove optically using a laser pickup. Since there is no physical contact with the record, no wear is incurred. However, this "no wear" advantage is debatable, since vinyl records have been tested to withstand even 1200 plays with no significant audio degradation, provided that it is played with a high quality cartridge and that the surfaces are clean.
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. A professional system employed by the Library of Congress produces excellent quality.
A smooth-tipped stylus (in popular usage often called a needle due to the former use of steel needles for the purpose) is used to play the recorded groove. A special chisel-like stylus is used to engrave the groove into the master record.
The stylus is subject to hard wear as it is the only small part that comes into direct contact with the spinning record. In terms of the pressure imposed on its minute areas of actual contact, the forces it must bear are enormous. There are three desired qualities in a stylus: first, that it faithfully follows the contours of the recorded groove and transmits its vibrations to the next part in the chain; second, that it does not damage the recorded disc; and third, that it is resistant to wear. A worn-out, damaged or defective stylus tip will degrade audio quality and injure the groove.
Different materials for the stylus have been used over time. Thomas Edison introduced the use of sapphire in 1892 and the use of diamond in 1910 for his cylinder phonographs. The Edison Diamond Disc players (1912–1929), when properly played, hardly ever required the stylus to be changed. The styli for vinyl records were also made out of sapphire or diamond. A specific case is the specific stylus type of Bang & Olufsen's (B&O) moving magnet cartridge MMC 20CL, mostly used in parallel arm 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%.
Other than the Edison and European Pathé disc machines, early disc players, both external horn and internal horn "Victrola" style models, normally used very short-lived disposable needles. The most common material was steel, although other materials such as copper, tungsten, bamboo and cactus were used. Steel needles needed to be replaced frequently, preferably after each use, due to their very rapid wear from bearing down heavily on the mildly abrasive shellac record. Rapid wear was an essential feature so that their imprecisely formed tips would be quickly worn into compliance with the groove's contours. Advertisements implored customers to replace their steel needles after each record side. Steel needles were inexpensive, e.g., a box of 500 for 50 US cents, and were widely sold in packets and small tins. They were available in different thicknesses and lengths. Thick, short needles produced strong, loud tones while thinner, longer needles produces softer, muted tones. In 1916, in the face of a wartime steel shortage, Victor introduced their "Tungs-Tone" brand extra-long-playing needle, which was advertised to play between 100 and 300 records. It consisted of a brass shank into which a very hard and strong tungsten wire, somewhat narrower than the standard record groove, had been fitted. The protruding wire wore down, but not out, until it was worn too short to use. Later in the 78 rpm era, hardened steel and chrome-plated needles came on the market, some of which were claimed to play 10 to 20 record sides each.
When sapphires were introduced for the 78 rpm disc and the LP, they were made by tapering a stem and polishing the tip to a sphere with a radius of around 70 and 25 micrometers 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 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 micrometers e.g. 13 micrometers. 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 the costs were effectively offset by their extended lifespans.
The next development in stylus form came about by the attention to the CD-4 quadraphonic sound modulation process, which requires up to 50 kHz frequency response, with cartridges like Technics EPC-100CMK4 capable of playback on frequencies up to 100 kHz. This requires a stylus with a narrow side radius, such as 5 µm (or 0.2 mil). A narrow-profile elliptical stylus is able to read the higher frequencies (greater than 20 kHz), but at an increased wear, since the contact surface is narrower. For overcoming this problem, the Shibata stylus was invented around 1972 in Japan by Norio Shibata of JVC, fitted as standard on quadraphonic cartridges, and marketed as an extra on some high-end cartridges.
The Shibata-designed stylus offers a greater contact surface with the groove, which in turn means less pressure over the vinyl surface and thus less wear. A positive side effect is that the greater contact surface also means the stylus will read sections of the vinyl that were not touched (or "worn") by the common spherical stylus. In a demonstration by JVC records "worn" after 500 plays at a relatively very high 4.5 gf tracking force with a spherical stylus, played "as new" with the Shibata profile.
Other advanced stylus shapes appeared following the same goal of increasing contact surface, improving on the Shibata. Chronologically: "Hughes" Shibata variant (1975), "Ogura" (1978), Van den Hul (1982). Such a stylus may be marketed as "Hyperelliptical" (Shure), "Alliptic", "Fine Line" (Ortofon), "Line contact" (Audio Technica), "Polyhedron", "LAC", or "Stereohedron" (Stanton).
A keel-shaped diamond stylus appeared as a byproduct of the invention of the CED Videodisc. This, together with laser-diamond-cutting technologies, made possible the "ridge" shaped stylus, such as the Namiki (1985) design, and Fritz Gyger (1989) design. This type of stylus is marketed as "MicroLine" (Audio technica), "Micro-Ridge" (Shure), or "Replicant" (Ortofon).
It is important to point out that most of those stylus profiles are still being manufactured and sold, together with the more common spherical and elliptical profiles. This is despite the fact that production of CD-4 quadraphonic records ended by the late 1970s.
Early materials in the 19th century were hardened rubber, wax, and celluloid, but early in the 20th century a shellac compound became the standard. Since shellac is not hard enough to withstand the wear of steel needles on heavy tone arms, filler made of pulverized shale was added. Shellac was also fragile, and records often shattered or cracked. This was a problem for home records, but it became a bigger problem in the late 1920s with the Vitaphone sound-on-disc motion picture "talkie" system, developed in 1927.
To solve this problem, in 1930, RCA Victor made unbreakable records by mixing polyvinyl chloride with plasticisers, in a proprietary formula they called Victrolac, which was first used in 1931, in motion picture discs, and experimentally, in home records, the same year. However, with Sound-on-film achieving supremacy over sound-on-disc by 1931, the need for unbreakable records diminished and the production of vinyl home recordings was dropped as well, for the time being.
The Victrolac formula improved throughout the 1930s, and by the late 30s the material, by then called vinylite, was being used in records sent to radio stations for radio program records, radio commercials, and later, DJ copies of phonograph records, because vinyl records could be sent through the mail to radio stations without breaking. During WWII, there was a shortage of shellac, which had to be imported from Asia, and the U.S. government banned production of shellac records for the duration of the war. Vinylite was made domestically, though, and was being used for V-discs during the war. Record company engineers took a much closer look at the possibilities of vinyl, possibly that it might even replace shellac as the basic record material. After the war, RCA Victor and Columbia, by far the two leading records companies in America, perfected two new vinyl formats, which were both introduced in 1948, when the 331⁄3 RPM LP was introduced by Columbia and the 45 RPM single was introduced by RCA Victor. For a few years thereafter, however, 78 RPM records continued to be made in shellac until that format was phased out around 1958.
Early "acoustical" record players used the stylus to vibrate a diaphragm that radiated the sound through a horn. Several serious problems resulted from this:
The introduction of electronic amplification allowed these issues to be addressed. Records are made with boosted high frequencies and reduced low frequencies, which allow for different ranges of sound to be produced. 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. Phono inputs are starting to reappear on amplifiers in the 2010s due to the vinyl revival.
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") preamplifiers, which include multiple, selectable equalizations, are no longer commonly available. However, some vintage preamplifiers, 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. 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.
Turntables continue to be manufactured and sold in the 2010s, although in small numbers. While some audiophiles still prefer the sound of vinyl records over that of digital music sources (mainly compact discs), they represent a minority of listeners. As of 2015 the sale of vinyl LP's has increased 49–50% percent from the previous year although small in comparison to the sale of other formats which although more units were sold (Digital Sales, CDs) the more modern formats experienced a decline in sales. The quality of available record players, tonearms, and cartridges has continued to improve, despite diminishing demand, allowing turntables to remain competitive in the high-end audio market. Vinyl enthusiasts are often committed to the refurbishment and sometimes tweaking of vintage systems.
In 2017, vinyl LP sales were slightly decreased, at a rate of 5%, in comparison to previous years' numbers, regardless of the noticeable rise of vinyl records sales worldwide.
Updated versions of the 1970s era Technics SL-1200 (production ceased in 2010) 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 and occasionally in other genres, the turntable is used as a musical instrument by DJs, who use turntables along with a DJ mixer to create unique rhythmic sounds. 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 Wizzard 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. In the 2010s, many hip hop DJs use DJ CD players or digital record emulator devices to create scratching sounds; nevertheless, some DJs still scratch with vinyl records.
The laser turntable uses a laser as the pickup instead of a stylus in physical contact with the disk. It 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.
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. In 2008, LP sales grew by 90% over 2007, with 1.9 million records sold.
USB turntables have a built-in audio interface, which transfers the sound directly to the connected computer. Some USB turntables transfer the audio without equalization, but are sold with software that allows the EQ of the transferred audio file to be adjusted. There are also many turntables on the market designed to be plugged into a computer via a USB port for needle dropping purposes.
Responding to longtime calls by fans and disc jockeys, Panasonic Corp. said it is reviving Technics turntables–the series that remains a de facto standard player supporting nightclub music scenes. The new analog turntable, which would come with new direct-drive motor technologies that Panasonic says would improve the quality of sound, would be released sometime between April 2016 and March 2017, the Japanese electronics company announced on September 2, 2015.