Cassette

Cassette, cassette, or caset (of the French cassette) are a format of recording of magnetic tape sound widely used; designated often cassette of audio, tape cassette, or simply cassette. Although they were predicted originally like means for the dictation, the improvements in the fidelity of the sound lead to that the cassette supplanted the tape recording reel-to-reel in the majority of its uses. Their applications extended of audio portable of homemade recording to the data storage for computers. Between years '70 and beginning the '90, the cassette was one of both more common formats for prerecorded music, next to discs of vinyl and more ahead to the compact disc.

The compact cassettes consist of two coils miniature, between which a magnetic tape goes. These coils and their other pieces are within a protective plastic housing. In the tape two pairs of stereo landing fields are available, a one by each face (face reproduces when cassete is inserted with its lateral coatings facing for above and the other when of the return occurs him -- expensive B).

The cassette is an analogical support, although also digital tape formats were developed: for example the Audio Tape Digital (DAT) and the Digital Compact Cassette (DCC).

History

The Compact Audiocasete is means for the storage of audio that was introduced in Europe by the Philips company in 1963, and in the Member States in 1964, under registered tradename with the name of Compact Cassette. Although there were other systems of magnetic tape cartridge in that then, the Compact Cassette got to be dominant as a result of the decision of Philips (in response to the pressure of Sony) to license the format free of charge. One became then a popular alternative and rewriteable to the vinyl disc during years '70.

Introduction of the music cassettes

The mass production of Audio Compact Cassettes began in 1964 in Hannover, Germany. The cassettes of prerecorded music, also known like Musicassettes (been brief M.C.); they were launched in Europe in end of 1965. The Musicasetes was introduced in the Member States in September of 1966 with an opening offer of forty and nine (49) titles by The Mercury Record Company, a American branch of Philips.

Nevertheless, this initially it had been designed for dictation and portable use; and the quality of the first reproducers was not suitable for music. Additional to it the first models had faults of mechanical design. In 1971, Advent Corporation introduced its model 201 that combined the reduction of Dolby noises B type with a chromium dioxide tape (CrO2). The result was a format apt for the musical use and the beginning of the era of cassettes and reproducers of hi-fi.

During years 1980, the popularity of the cassette grew more as a result of the portable recorders of pocket and the reproducers hi-fi like the Walkman de Sony, whose size was not much greater than the one of the own cassette.

Aside from the advances purely technicians of the cassettes, these also served like catalysts for the social change. Their durability and copied facility of helped to bring music underground rock and punk behind the Iron Curtain, creating a balance for the western culture between the youngest generations. For similar ratios, the cassettes got to be popular in developing countries. In 1970 in India, they were blamed to bring undesired influences in traditionally religious areas.

The technology of the cassette created a market in growth for the pop music in the India, criticized by conservatives whereas it created an enormous market for the legitimate companies of the recording and pirateadas tapes.

In some countries, particularly in the developing world, the cassettes still continue being the dominant means to buy and to listen to music.

Declivity

In many western countries, the market for the cassettes is in serious declivity from its tip at the end of the '80. This has noticed particularly with the prerecorded cassettes, whose sales were reached about those of the CDs during the first years of the decade of the '90. In 1993, only the CD shipments reached 5 million, an increase of 21%, whereas the cassette shipments diminished a 7% (to approximately 3.4 million).

In 2001 the cassettes constituted only 4% of all the music sold in the Member States. Nevertheless, in date 2006, the cassettes in target still are taking place and they are sold retail in many tents, and the facilities for the duplication of the cassette continue being available.

In spite of the ample availability of means of hi-fi, the cassettes also continue being popular for the specific uses, including audio of car and other difficult environments. The cassettes are typically rougher and resistant to the dust, heat and shocks that the majority of average digitalizes (especially CDs). Its lower fidelity does not consider a serious disadvantage within the typically noisy interior of the automobile. Although the modern technology of buffering in many new cd players for car gives a term at the time of recovering of intermittent jumps, the cassette continues being more resistant as opposed to periodic and repeated shocks. Nevertheless, the cassettes have generally poor resistance at heat found the excessive levels in cars parked during the summer.

Whereas the digital recorders of voice now are common field, the cassette recorders (or frequently microcassette) tend to be cheaper and of quality sufficient to take notes in educative situations of office or. Still audiobooks, spoken services of church and other materials are sold in cassette, because one more a lower fidelity usually is not a disadvantage for such content. Whereas the majority of the publishers sells audiobooks in CD, generally also they offer a version in cassette in a low price. In the use of audiobooks, where the recordings can last several hours, the cassettes also have the advantage of the support of 120 minutes of dialog whereas the average CD maintains 80 less than.

Whereas the cassettes and the related equipment have marginalized more and more in the field of the commercial sales of music, the analogical tape recording continues being a desirable option for some. In 2002, Imation received a concession of 11.9 million dollars of the National Institute of Standards and Technology for investigation in the increase of capacity of data of the magnetic tape.

Some musicians still prefer to register his másters in magnetic tape for artistic ratios, and some consumers prefer to buy cassettes due to a supposed wealth of the analogical sound.

Recently the manufacturers of the cassette have stopped producing it and will leave the market definitively at the end of December of the 2008, since this one has been strongly displaced by average digitalizes like ipod, and in addition already is available in the most recent market in storage technology, Blu-Ray, that is the equivalent to more than 3,000 cassettes.

Characteristics

In order to record magnetic tapes the system of analogical mechanical recording is used.

The cassette is made up as much of a strip of plastic of fine thickness so that flexible and it is extended, that can get to have several meters of longitude. This plastic strip wears a fine layer of magnetic material that will keep the data when orienting itself the magnetic poles thanks to the action of a reading mall pillow/writer. This tape is protected by a rectangular and flat box of plastic that has two coils with turn capacity which they are united to both ends of the tape (the plastic strip).

The cassette was a step forward in convenience from the tape recorders, although due to its limitations of size and speed, the quality was initially poor in comparison with these. The width of the tape is of 3.18 mm, occupying each landing field stere 0.79 mm. The speed of reproduction is of 47.6 mm/s (millimeters every second), of right to left. In comparison, the typical tape recorder for consumer use had a tape width of 6.35 mm (with each landing field stere occupying 1.59 mm) and one 190 speed of 95 or mm/s.

The magnetic tape reproducer or casets was called billet and, if he were compact and pórtatil, they walkman.

Walkman (walking by Manhattan) is a registered tradename by the Sony corporation of Japan for its reproducers of portable cassettes, originally was called “Sound About” in its first model Sony TP ls 2.

The cassette of audio originally offered a monophonic registry of 6o minutes with a range of 60 8 Hertz to kHz ±3dB with a report signal to noise of 40 dB that was appropriate to record dictations, later improved to offer esterefonía with two 30 separated channels dB a frequency range of 50 12 Hertz to KHz ±3dB and one report s/n of 45dB that is appropriate to hear music.

The provided basic reproducers of reduction of noise Dolby B had a frequency response of 40 13 Hertz to kHz ±3 dB with perpendicular tape and 40 15 Hertz to kHz ±3dB with tape of chromium dioxide a report signal db and 58 50 noise of dB with activated the Dolby system, you distort below 1% and a jimoteo or tremolo smaller than 0.1%; what vinil “long play” allowed a clean sound like the one of discs.

Besides the recording of audio, other uses of the cassette include the data retention digital modulated of analogical form, very popular in the microcomputers with which he was used like storage method.

Type of cassette tapes

Longitude

The cassette, following the longitude of the tape, allows diverse durations of recording. Indeed the name of the tape already indicates the duration of the same. Smallest, the C5, allows to 5 minutes, two minutes and average by face. Longest, C120, allows two hours of recording (60 minutes by face).

To greater longitude, thinner they are the tapes, in order that they fit in the same cartridge that those of smaller longitude. When thinner they are the tapes worse adapted the guides of the own cartridge, which can cause an evil contact head-tape that can originate that the tape is coiled (is unrolled and enlists being able to spoil the reproducer.

The manufacturers energetically advise against the use of C120 and, to a lesser extent, C90. In addition, to greater longitude, the tape weighs more and so the useful life of the mall pillow is used excessive respect. The deficient contact head-tape also can cause losses in answer of frequency and other problems.

Magnetic material

Diverse kinds of material magnetic for the cassettes are used. Each of them has different injunctions from polarization (bias) and equalization. According to this material it is possible to be distingir four types of tapes:

• Tapes IEC type I or of standard rate. They are based on ferric oxide gamma (Fe2O3) and was the original type of tapes. They use an equalization of 120 µs.
• Tapes IEC type II. Around 1970, 3M developed a cobalt trial combined with a technique of double-coating with the aim of increasing the volume average of exit of the tape. At the same time, BASF introduced chromium dioxide (CrO2). This type of tapes requires an equalization of 70 µs.
• Tapes IEC type III. Sony experimented with a double tape castrates simultaneously using ferric oxide and chromium dioxide. “ferrichrome” was called (FeCr). These tapes were in favor only available of a short period of time in 1970.
• Tapes IEC type IV or of metal (Metal Cassettes). Also they use equalization of 70 µs, and provide new advances and improvements in the quality of sound as well as more resistance to the wearing down.

The quality is perpendicularly reflected in the price, being the cheapest tapes most expensive Type I and Type IV. The tapes Type II are considered like of quality CD and the tapes Type IV like of more quality than the CD, for levels of higher and Super volume Audio CDs.

The type of tape indicates with notches in the part superior of the cover. The tapes type only I have a pair of notches (one to each end) for protection of document. The tapes type II have an additional pair next to those of protection of document. The tapes type IV have a third pair but in means of the cover. These notches allow that the billets recognize the type of tape automatically and choose the parameters of polarization (bias) and equalization of automatic form. Even so, most of the current models lack this characteristic, and some only allow to the tape use type I.

If tapes are used type II and type IV in a billet designed exclusively for tapes type I, they will take place sound distortions and a poor quality.

Historical development

In 1963, the Philips house launched to the market the first recorders for cassette tapes.

The compact cassette (as it were called originally) was patented in 1964, by the division of the Netherlands of the Philips Company, but the new invention later did not acquire relevance until a time.

In 1965, it appeared the virgin magnetic tape, that was commercialized with different formats.

The cassette had sense because the tape recorder was not an equipment of easy portable transport nor, the cassette, of much smaller size and compact, it wanted to resolve these problems and to look for that strip of market that was not being covered.

The commercial viability of the new invention went away introducing slowly. In the beginning, the '60 end of and principle of the '70, the demand was so poor, that the albums of music in cassette were even launched after they had put the LPs on sale. (As it happens today with the cinema that first is released in cinema and after a period puts to a sale the DVD). The little demand is explained because the first cassettes had disqualified the function to record, were only reproductive nonrecorders.

The quality of the sound of the cassette I improve remarkably with the introduction of the systems of reduction of Dolby noises, which attracted new consumers and the Ampex companies, Sony and TDK began to produce them in mass.

The blank tape was introduced by the Japanese house Maxell, in the middle of the '70, and, at the end of years '70, Maxell and TDK distributed the market of the blank tapes.

In 1980, it appeared the tape of higher quality metal and the discográficas companies began simultaneously to launch to the LPs and tapes of cassette.

Paralelamente began to appear walkmans (small portable reproducers of cassette with earpieces) that allowed the user to listen to their music at any time and in any place. The models of walkman in addition began to incorporate tuners of radium AM/FM, adding still more diversity to what usuary could program.

Walkmans then carried out the same social revolution that, at the present time, the reproducers of mp3. The user could record in a tape the selection of music that believed opportune and to take it there where it wanted.

Successors

The effective technical development of the cassette stopped when average digitalizes of recording such as the DAT and the MiniDisc were introduced at the end of the '80 and beginnings of years '90. Anticipating the exchange of analogical format to digitalis, many important companies such as Sony changed their approach towards new means.

In 1992, Philips introduced the Digital Compact Cassette (DCC), tapes DAT are similar in some factors to the Audio Cassette of Compact. It was directed mainly to the market of the consumer. A “deck”, platina or recording apparatus/airplane of DCC could reproduce both types of cassettes. On the contrary that the DAT, that were accepted in professional use because it could record without losses, the DCC was not successful in homemade or mobile environments, and it was stopped making in 1996.

In 1992 Sony the Minidisc without too much success launches. The idea was to be an alternative to cassete and the CD, with a capacity of greater storage to the cassette and a smaller size to the CD.

The microcassette in many cases has supplanted the audio cassette of the same size in situations where it is all the fidelity of the voice-level that is required. For example, in the machines of dictation and the answering machines. Even these, alternatively, are beginning to take to the digital cash registers of several descriptions. Given to the increase of use of CD-R, MP3 stored in memory-flash and iPod like reproducers, the phenomenon of “homemade recording” has changed with difference, when obtaining right now, the data, or are of audio or any other thing, Internet, with standard qualities.

Due to demand of the consumer, the cassette has continued being influential in design almost two decades after its declination. Whereas the compact disc (or CD) grew in reputation, the cassette-formed adapters audio were developed to provide a way economic and clear to obtain functionality of the CD in the vehicles equipped with cassette billets. A reproducer of portable CD did that its line, besides digitalis, outside analogous to the power to connect with the adapter the reproducer of CD to the billet of Cassettes. These adapters also continue working with reproducers MP3, and are generally more reliable than the transmitters of FM that are due to use to adapt cd players to MP3s. Reproducers MP3 formed like cassettes of audio also have made possible that they can be inserted in any reproducer of audio cassette and to communicate with the head as if they were perpendicular cassettes.

Repair

The tapes contain mobile parts like bearings that can be deteriorated, causing that clogs or breaks the magnetic tape. This does not mean the aim than it is recorded there: It To another housing can be removed the tape from the housing and be transplanted. The tapes that have eaten the reproductive apparatus/airplane, as are described next, can be recovered in many cases, for example, coiling them again on a circular surface, as it can be a ball-point pen, and leaving smoothest the surface possible. One more a more consistent repair can be carried out on a tape cut by means of aligning carefully the two extreme parts and both bonding with a special tape joint to unite (the perpendicular sticky tape would not have never to be used in recordings of audio because it will be clogged continuously), for after to trim the leftover with scissors or a knife of precision, being done possible a basic reproduction for its copy to external means like a digital recorder or a personal computer.

The highest quality tapes come made with screws, so that the tape can be disassembled and be mounted without no problem. It can be very useful to practice first with empty tapes. It has to have well-taken care of and to assure that the coil and the tape they are in the right order of the cassette before the assembly and of which all the parts of which it consists, fit. If the parts of the housing are bonded with glue, they are possible to be separated little by little using a fine metal leaf (like a screwdriver or a fine knife) in the edge of both halves of the housing, while care of not damaging the coil is had.

Often the coils are damaged in the operation, so that there is to replace on the other new housing.

External Links

• Deck covers: Recopilatorio of images of hundreds of cassette tapes

It is also seen

References

1. ↑ Camras, Marvin (1985), Magnetic Tape Recording, New York: They go Nostrand Reinhold. ISBN 0-442-21774-9.
2. ↑ Eric D. Daniel, C. Dennis Mee, Mark H. Clark (1998), Magnetic Recording: The First 100 Years, New York: McGraw-Hill Professional. ISBN 0-07-041275-8.
3. ↑ IEC: “Part 7: For cassette commercial tape record and domestic uses”, in Standard International IEC 60094-7: Magnetic covers sound recording and reproducing systems. Geneva: IEC, 1994. ISBN 0-580-22909-2
4. ↑ Leonard Copland, Robert Johns (November of 1966). “The Tape Cartridge Comes Of Age”. Electronics World magazine.
5. ↑ “Part 7: For cassette commercial tape record and domestic uses”, International standard IEC 60094-7: Magnetic covers sound recording and reproducing systems. International Electrotechnical Commission, Geneva.
6. ↑ Werner Abelshauser, Wolfgang von Hippel, Jeffrey Allan Johnson, Raymond G. Stokes (2003). German Industry and Global Enterprise: BASF: The History of to Company. Cambridge University Press. ISBN 0-521-82726-4.
7. ↑ The Blank Tape Gallery. Consulted the 13 of September of 2006.
8. 'Sony Unveils the Minidisc' (The Syracuse Newspapers ed.), The Syracuse Newspapers, New York, Member States of America

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