A record player , also known for short as a record player (English: phonograph , record player or turntable ), is an electrical device for playing records . Turntables generate an electrical analog signal that is reproduced through an amplifier through loudspeakers . Until the 1980s, turntables were a standard component of stereos , as recorded music was preferred to be published on vinyl. With the triumph of the compact cassette and the compact disc in the 1980s, they lost a lot of their importance.
Since 2012, more than a million new vinyl records have been sold in Germany every year. Sales of new turntables are also increasing. Newly produced record players are partly equipped with a USB connection or with Bluetooth and thus have an integrated analog-digital converter . These integrated A / D converters can be used to digitize records.
The forerunners of the record player were the mechanical devices, the phonograph and gramophone, invented around 1880 . Emil Berliner , who applied for the patent in 1887, is considered the inventor of the record and the gramophone . The name record comes from him . At the time of the First World War , the gramophone prevailed over the phonograph. From 1920 there were electrically powered turntables, for example from Albert Ebner & Co. From 1926 the first electric pickups (for example from General Electric ), whose signal could now be amplified in the radios that were also spreading . These developments were initially independent of one another: there were gramophones with an electric motor and mechanical sound generation and also crank gramophones with - in some cases retrofitted - electric pickups. The first playback devices with an electric motor and electric pick-up were now called "electric gramophones". After electrical operation became common, the term "record player" became established.
It was the heyday of shellac records , they ran at 78 min −1 (revolutions per minute) and were sold in large numbers all over the world for over 60 years (from 1895 to 1957) and in some countries, e.g. B. India and the Philippines manufactured until the late 1960s. Early Beatles records appeared there in the 78 rpm format. Millions of shellac records still exist in archives and with private collectors today. It was not until the invention of vinyl that heavy, fragile records replaced the world in the mid-1950s. The new plastic not only made the records lighter, thanks to its finely structured, extremely smooth surface structure, it was now possible to write or write a stereo signal (via h / v) in the same place in the groove. and thus achieve a great increase in sound quality (introduction of the HiFi standard at the beginning of the 1960s), accommodate much more modulation through the filler font and that even at the much lower speeds (33⅓ min −1 for long-playing records and 45 min −1 for Singles).
In the 1950s, record changers with the option of inserting several records at the same time and playing them back one after the other became widespread. For this purpose, the plates were placed on an extended central axis and held in place with a mechanism. When a record was finished playing, the next was dropped on the turntable. Some models had a scanning function that determined the diameter of the disks and thus made it possible to play disks of different sizes one after the other. The disadvantages, however, were that the disks could not be turned over and only one side per disk could be played. For an optimal change from double albums to plate changers, the plate pressure here is 1-4, 2-3. In addition, the playback speed could not be recorded, which is why you could only insert records with the same speed. The panels also lay on top of each other and were dropped somewhat roughly from the central axis, which could possibly cause slight damage and scratches.
From 1920 until well into the 1960s, the record had a quasi-monopoly as a sound carrier , which was first broken up by the compact cassette (CC) and later by the compact disc (CD). The market share of analog turntables has only been small since the 1990s, but not entirely gone. The number of turntables sold in 2005 was around 100,000 and the trend is rising. In 2006 approximately 170,000 non-portable CD players and 8.3 million MP3 players were sold.
Pickup and arm
In turntables, a metal, sapphire or diamond needle or, since the 1990s, a laser ( laser record player ) scans the groove of the record. The mechanical pickup converts the slight vibrations of the needle into weak electrical currents, which must be equalized and amplified in order to be able to reproduce a sound signal. When scanning with a laser, the signal obtained is also processed in an exclusively analogue way.
The pickup in turn hangs on the tonearm , which can be balanced in different ways. The most common is balancing with a counterweight. Mechanically more complex constructions are balanced with an adjustable spring. The quality of the arm depends essentially on factors such as the way in which the arm is supported, on its mass, its rigidity, the surface and, in sum, these and other factors on its natural resonance. A distinction is made between radial tonearms (also: rotary tonearms or simply: tonearms) and the rare tangential tonearms. With a tangential tonearm, the tape head moves on a rail parallel to the radius of the turntable. This avoids the skating power.
Turntables can generally play records at two speeds: 33⅓ min −1 (revolutions per minute) and 45 min −1 . Playing older records at 78 min −1 or 16⅔ min −1 is also seldom possible.
Turntables are made with different drive technologies, i.e. ways in which the turntable is set in rotation. These different types of drive are partly due to historical reasons, but partly also have been developed to meet various technical requirements, e.g. B .:
- The turntable runs up quickly
- Low transmission of motor vibrations to the platter
- Precise controllability of the turntable speed
The direct drive , the belt drive and the friction wheel drive are or were widespread .
With direct drive, the axis of the turntable is also the axis of the drive motor . On some models, e.g. B. Technics SL-1200 and its variants, the turntable is part of the motor. Here the electromagnets of the motor act directly on the platter, or the platter rests on the rotor of the motor. The change in the turntable speed is achieved directly by changing the speed of the motor. If the motor rotation is transmitted to the turntable axis via a gear , e.g. B. to use a motor with a higher speed, is also spoken of direct drive.
Directly driven turntables are particularly common in the DJ sector. They can be built with an extremely short ramp-up time. The motors used could cause some cheap turntables to transmit a jerk when the rotor of the motor moves to the next position in the armature . High-quality direct-drive radio drives such as B. the electrical measurement technology Wilhelm Franz outbid the best belt-driven drives available today in all relevant measurement disciplines. A disadvantage of the direct drive is the very high production and development costs of the motor, drive and control with PLL control . With the currently small quantities, especially in the high-end sector, development and production would be difficult to achieve economically.
With a belt drive, the rotation of the motor axis is transmitted to the turntable with a rubber belt or band. This type of construction is widespread, as the belt drive allows mechanical decoupling between the motor and platter, and thus undesired vibrations in the platter can be minimized.
With a belt drive, the speed is controlled either by controlling the motor speed or by using different gear ratios between the motor axis and the platter. This is achieved with running disks of different sizes on the motor axis. The drive belt must be changed from one pulley to the other to change the speed. With dual turntables with Vario-Pulley, the belt is shifted automatically, and the segmented drive shaft of variable diameter even enables fine speed adjustment (pitch).
The advantage of the belt drive is that turntables with good running properties can be constructed with little development effort. Disadvantages are higher wow and flutter, speed drift due to temperature or humidity fluctuations, speed fluctuations due to the modulation of the tone groove (loud passages are played at a lower pitch than soft ones because of the braking effect of the groove) and vibrations due to the slip of the belt.
These disadvantages can be reduced structurally, mass drives with heavy turntables take precedence over short-term fluctuations in speed due to the inertia. Some constructions such as B. Philips drives of the 1970s with "direct control" or the turntables CS5000 and CS750 from the manufacturer Dual and their descendants have control electronics that record the speed directly on the turntable. The dual models have 200 teeth milled into the sub-platter, which are detected by a light barrier. The signal generated from this is compared with a quartz-based reference and speed deviations are corrected immediately. In this way the usual drift of belt drives is avoided.
The disadvantage of this solution is the high time constant in the loop filter of the PLL control, which is necessary because of the elasticity of the belt. In contrast to the direct drive, the PLL control with the belt drive cannot compensate for short-term fluctuations in speed.
Belt-drive record players are still produced today by Alfred Fehrenbacher GmbH in St. Georgen. Between 15,000 and 20,000 DUAL devices are produced and sold annually.
With the friction wheel drive, the rotation is transmitted to the cylindrical inner edge or the flat and finely machined underside of the plate by means of a rubber wheel. The vibration-damped and often permanently running motor drives the friction wheel, which is only temporarily pressed on, via a precise shaft, which in turn transfers the rotation to the inside of the turntable. This enables a very good transmission of the torque to the turntable and thus a quick revving of the turntable. However, the disadvantage is the risk of coupling vibrations from the motor into the platter via the relatively rigid coupling between the motor axis and the turntable.
The speed control takes place here by means of different gear ratios between the motor axis (also called step axis) and the friction wheel.
Friction wheel drive is only offered by a few manufacturers today, and only for cheap drives. Classics built in the 1950s and 1960s are e.g. B. EMT 927 and 930, Garrard 301 and 401 as well as the Thorens TD 124. The latter works with a combination of friction wheel and belt drive. The motor drives the friction wheel that drives the platter via a short belt. This decouples the motor from the turntable. Almost all manufacturers such as B. Braun , Perpetuum Ebner (PE), Elac , Bang & Olufsen , Lenco and above all Dual used this drive concept in the 1950s and 1960s.
Record players have various auxiliary systems for comfortable, low-risk playback of the record. If the tonearm has to be placed on the entry groove of the record by hand and at the end of the playback process it must be placed from the exit groove onto the tonearm support, there is a risk that the record or the pickup will be damaged. There is therefore often a lever for raising and lowering the tonearm in order to facilitate the gentle vertical movement.
In the semi-automatic mode , a mechanism automatically restores the tonearm to the support bracket at the end of the playback process and the drive is switched off. To do this, a feeler pin detects the angle of the tonearm and engages the feedback mechanism that is driven by the turntable. In order for the angle detection to work reliably, the discharge groove on the plate is particularly coarse-spiral.
In fully automatic operation , a start button causes the tonearm to move over the beginning of the record and lower it there. The HMK-PA 1205 from VEB Phonomat Pirna-Rottwerndorf recognizes the beginning optically, can find the pauses between the individual tracks after scanning the record and is thus also able to play selected tracks.
If a single is put on, automatic devices must recognize that the beginning is further inside. If there is no record, the tonearm must not be lowered. Feeler pins on the platter are used for this purpose, for example.
Plate changers extend the fully automatic operation by changing the plates, which are automatically removed from a shelf and put back.
Turntable base concepts
The sub-chassis carries the turntable construction (tonearm, turntable with drive) and has a suspension and damping both towards this and often towards the installation surface.
A board player is a turntable with a less massive turntable. The Rega Planar is a typical representative of this type of running gear. Synchronization and footfall sound absorption must be achieved through good control and a spring-loaded / damped suspension in the sub-chassis.
With mass drive particularly heavy massive platter are referred to a turntable. Due to its inertia, the large mass of the turntable should prevent undesired vibrations when playing a record. The mass drive is usually not decoupled from the turntable's sub-chassis by springs or dampers. The large mass is intended to achieve good synchronization.
Bulk drives weigh up to 130 kg, for example. Bulk drives can often be found in the so-called high-end market segment. The numbers are small. Manufacturers are often small, specialized workshops.
The motor for driving a mass drive is sometimes set up separately and therefore decoupled. The power is transmitted via a rubber belt or a thin rubber band.
Advantages and disadvantages
Due to the particularly high inertia of a mass drive, vibrations from the environment (impact noise) or fluctuations in the drive motor are to be minimized.
Mass drives sometimes allow a free choice of drive motor and tonearm, as the individual components are often separately available and can be set up.
Due to the high inertia of a mass drive, it takes a long time until the mass drive can be accelerated to the desired rotational speed or decelerated again.
Due to the high use of materials, precision and exclusivity, bulk drives are more expensive than board players.
Due to the use of solid material, under certain circumstances a "bell effect" or "ringing" can occur when playing.
Due to the design, a ground drive is suitable for the optional use of record clamps or additional weights (pucks), which additionally press a record onto the turntable. This means that the record is more level. This should also increase the smoothness.
Portable turntables appeared in the 1950s. Initially, it was a matter of handy devices that only offered space for 7 " singles , later mostly a structurally particularly large radio recorder in which the record was inserted from the front through a flap or from above through a slot. This was made possible by the tangential technology There were also turntables that were meant to be built into the car.
The aim of these devices was to be able to use your own record collection on the go without having to transfer the vinyl records to tapes. The high price (well over 100 DM at the time) and the weight prevented market success. In addition, there was competition from ever smaller portable cassette players such as the Walkman .
Around 1960, hybrid devices that combined turntables and tape recorders came on the market. The English company Gramdeck brought a tape adapter for turntables onto the market in 1959, while the English Gramophone Company offered a record player as an attachable accessory for their Voicemaster tape recorder in 1961.
For some time now there has also been a vinyl recorder with which one can record records without pressing them - here the records are cut themselves, no templates for pressing tools. The ancestors of this device were the home foil cutting devices with 78 min⁻¹ released in the 1950s, but due to the high needle noise they could not hold their own against the early home tape recorders.
In addition to the usual mechanical scanning with needles, a record can be optically scanned without contact. Laser turntables use a laser beam and are located in the high-end area.
Another alternative is the software-supported "scanning" of a high-resolution optical digitized material in a computer. This method is used in the reconstruction of historical sound recordings.
Among other things, the record player SP 3935 produced by RFT in the late 1980s has a speed adjustment ( pitch control ) and a stroboscopic display for control.
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