The audio tape recorder tape deck or tape machine is an audio storage device that records and replays sound, including articulated sound, typically using magnetic tape , whether wound to the reel or on the cassette, for storage. In its current form, it records the fluctuating signal by moving the ribbon on the head of the tape that polarizes the magnetic domain in the recording according to the audio signal. Recording-recording devices include reel-to-reel tape decks and cassette decks.
The use of magnetic tapes for sound recording originated around 1930. The bandable bands revolutionized both radio broadcast and the music recording industry. It gives artists and power producers to record and re-record audio with minimal loss in quality and easily edit and rearrange the recording. The alternative recording technology of the era, transcription discs and wire recorders, can not provide quality and functionality close to this level. Because some of the early improvements increase the loyalty of the reproduced sound, magnetic tape has become the highest quality analog voice recorder medium available. In the first decade of the 21st century, analog magnetic tapes have been largely replaced by digital recording technology for consumer purposes, although some still record audio with analog.
Prior to the development of magnetic tape, magnetic wire recorders have successfully demonstrated the concept of magnetic recording, but they never offer audio quality that is comparable with other recording and broadcasting standards at the time. Some individuals and organizations develop innovative uses for magnetic wire recorders while others investigate technological variations. One of the most important variations is the application of oxide powder on long paper. This German discovery is the beginning of a long series of innovations that have resulted in the recording of today's magnetic tapes.
Video Tape recorder
History
Wax strip recorder
The earliest known audio tape recorder is a non-magnetic, non-electric version created by the Volta Alexander Graham Bell Laboratory and patented in 1886 ( U.S. Patent 341,214 ). It uses a wax-covered sheet of paper that is 3 / 16 -inch-wide (4.8 mm) coated by dipping it into a wax solution bees and paraffins and then have one side scraped clean, with the other side left to harden. The machine is made of solid wood and metal construction, and is powered by using a button tied to a flywheel. The wax strip is passed from an eight-inch reel around the rim of the pulley (with guide flanges) mounted on top of the V-pulleys on the main vertical shaft, where contact with the recording or playback stylus. The tape is then taken on another roll. Sharp note marker, driven by a vibrating mica diaphragm, cut the wax from the strip. In play mode, a dull and loose stylus is mounted, attached to a rubber diaphragm, carrying sounds reproduced through the ear canal to the listener.
Both recording and playback heads, alternately mounted on the same two posts, can be adjusted vertically so that multiple recordings can be cut in the same span of the same span > -inch-width (4.8 mm) strip. While the machine was never developed commercially, it was an interesting ancestor for a modern magnetic tape recorder similar in design. Cassettes and machines made by Bell's colleagues, examined at one of the Smithsonian Institution's museums, became brittle, and the thick paper roll was curved. The playback head of the machine is also missing. If not, with some reconditioning, they can be placed in working condition.
The wax coated recording medium is lower than the Edison wax cylinder medium, and the Edison wax cylinder phonograph becomes the widespread sound recording technology used for both entertainment and office dictation.
Celluloid strip recorder from Franklin C. Goodale
Franklin C. Goodale adapted film film for analog audio recording. He received a patent for his invention in 1909. The celluloid film was written and replayed with a stylus, in a manner similar to Edison's gramophone wax cylinder. The patent description states that the machine can store six recordings on the same movie strip, side by side, and it is possible to switch between them. One machine is on display at the Phonograph Museum in Mariazell in Austria. Only a few years later, in 1912, a similar process was used for Hiller's talk time, but the recording process was not generally used.
Photoelectric paper tape
In 1932, after six years of development work, Merle Duston, a Detroit radio engineer, created a tape recorder that uses low-cost, processed paper ribbons that can record sound and sound. During the recording process, the tape moves through a pair of electrodes which immediately prints the modulated sound signal as a black line visible to the surface of the paper tape. Sound tracks can be immediately played back from the same recording unit, which also contains photoelectric sensors, somewhat similar to the film-sound technology films of the era.
On August 13, 1931, Duston filed the USPTO Patent Application # 556.743 for "Methods And Apparatus For Electrical Recording And Feeling Of Voice Reproduction And Other Vibrations", and which was updated in 1934.
Magnetic recording
Magnetic recording was made in early 1878 by American engineer, Oberlin Smith, and was demonstrated in practice in 1898 by Danish engineer Valdemar Poulsen. The recording of the analog magnetic wire, and its successor, the tape of magnetic tape, involves the use of a magnetizable medium that travels at a constant speed through the recording head. An electrical signal, analogous to the sound to be recorded, is fed to the recording head, inducing a magnetization pattern similar to the signal. The playback head can then take a magnetic field change from the tape and turn it into an electrical signal to be amplified and played back through the loudspeaker.
Wire recorder
The first wire recorder was the Telegraphone created by Valdemar Poulsen in the late 1890s. Wire recorders for legal/office and telephone recording were made almost constantly by companies (especially American Telegraphone Companies) through the 1920s and 1930s. These devices were mostly sold as consumer technology after World War II.
The widespread use of wire recording devices took place in the decades from 1940 to 1960, following the development of cheap design licensed internationally by the Brush Development Company of Cleveland, Ohio and the Armor Research Foundation of the Armor Institute of Technology (then Institute of Technology Illinois) Technology). Both organizations licensed dozens of producers in the US, Japan and Europe. The wire was also used as a recording medium in the black box voice recorder for flight in the 1950s.
The consumer wire recorder is marketed for home entertainment or as a cheap substitute for commercial office dictation recorders, but the development of consumer magnetic tape recorders began in 1946, with BK 401 Soundmirror, using paper tape, rapidly pushing the wire recorder from the market..
Early steel tape recorder
In 1924, a German engineer, Dr. Kurt Stille, developed the Poulsen wire recorder as a dictation machine. The following year, a German colleague, Louis Blattner, who worked in England, licensed Stille's device and began working on a machine that would record on a magnetic steel band, which he called Blattnerphone.
The BBC installed Blattnerphone on Avenue House in September 1930 for tests, and used it to record King George V's speech at the opening of the Round Table Conference of India on 12 November 1930. Although not considered suitable for music, the machine continued to be used and moved to Broadcasting House in March 1932 , the second machine is also installed.
The tape was 6mm wide and 0.08mm thick, running at 5 feet per second; the recording time is 20 minutes.
In September 1932, a new model was installed, using a 3mm band with a 32 minute recording time.
In 1933, Marconi Company purchased the rights to Blattnerphone, and the newly developed Marconi-Stille recorder was installed at Maida Vale Studios on the BBC in March 1935. The quality was slightly improved, though it still tended to be clear that someone listened to the tape, like its reliability. The reservoir system containing the tape loop helps to stabilize the speed (there is also a smaller one just before the head). The tape was 3mm wide and covered a distance of 1.5 meters/sec. In September there were three recording rooms, each with two machines.
They are hardly easy to handle. The coil is heavy (and expensive) and the tape is portrayed like a razor blade. The tape can be photographed, especially when joined, which at that speed can quickly cover the floor with a sharp edged ribbon. Rewinding is done twice the recording speed.
However, apart from all this, the ability to make replicable tapes is very useful, and even with subsequent methods being used (Marcell-Miller's cut-off discs and optical films) Marconi-Stilles remained in use until the late 1940s.
Modern ribbon recording
The magnetic tape recording as we know it today was developed in Germany during the 1930s at BASF (then part of the chemical giant IG Farben) and AEG working with state radio RRGs. This is based on the findings of Fritz Pfleumer in 1928 on paper ribbons with lacquered oxide powder. The first practical tape recorder from AEG was Magnetophon K1, demonstrated in Germany in 1935. Eduard SchÃÆ'¼ller of AEG built the recorder and developed ring-shaped recording and playback heads. It replaces a needle-shaped head that tends to damage the tape. Friedrich Matthias of IG Farben/BASF developed recording tapes, including oxides, binders, and supporting materials. Walter Weber, who worked for Hans Joachim von BraunmÃÆ'¼hl in the RRG, invented the AC biasing technique, which radically improved the sound quality.
During World War II, the Allies realized that some German officials made radio broadcasts from several time zones almost simultaneously. Analysts such as Richard H. Ranger believe that the broadcast must be transcription, but their audio quality can not be distinguished from the live broadcast and their duration is much longer than is possible even with a 16 rpm transcription disk. (The Allies were aware of the existence of Magnetophon recorders before the war, but not the introduction of high frequency bias and PVC-backed bands.) In the final stages of the war in Europe, the Allies captured a number of German Magnetophon Records from Radio Luxembourg arousing great interest. This recorder combines all the key technological features of modern analog magnetic recording and is the basis for future developments in the field.
Maps Tape recorder
Commercialization
Developments in America
The development of magnetic tape recorders in the late 1940s and early 1950s was associated with the Brush Development Company and licensee, Ampex. The equally important development of the magnetic tape media itself is led by the Minnesota Mining and Manufacturing (3M) company.
In 1938, S.J. Began leaving Germany and joining the Brush Development Company in the United States, where work continued but attracted little attention until the late 1940s when the company released its first consumer tape recorder in 1946: Soundmirror BK 401. Several other models were quickly released in recent years, next year. The tape was originally made of paper coated with magnetite powder. Mining Minnesota & amp; Manufacturing Company (3M) replaced it with plastic cassette in 1948.
American audio engineer John T. Mullin and entertainer Bing Crosby are key players in the commercial development of magnetic tape. Mullin served in the US Army Signal Corps and posted it to Paris in the final months of World War II. His unit was tasked to find out everything they could about German radio and electronics, including the investigation of claims that Germany had experimented with high-energy radio rays as a tool to disable the electrical system of aircraft. The Mullin unit quickly assembled a collection of hundreds of low-quality magnetic dictators, but it was a chance visit to a studio in Bad Nauheim near Frankfurt while investigating radio ray rumors, which resulted in a real prize.
Mullin was given two high-fidelity AEG 'Magnetophon' recorders and fifty rolls of tape. He told them to be sent home and for the next two years he worked on the machine constantly, modifying them and improving their performance. The ultimate goal is to attract the interest of Hollywood studios in using magnetic tapes for movie soundtrack recording.
Mullin gave two general demonstrations of his machines, and they caused a sensation among American audio professionals; many listeners really do not believe that what they hear is not a live show. With luck, a second demonstration of Mullin was held at the MGM studio in Hollywood and in attendance that day was Bing Crosby's engineering director, Murdo Mackenzie. He arranged for Mullin to meet Crosby and in June 1947 he gave Crosby a personal demonstration of his magnetic tape recorder.
The Effect of Bing Crosby
Bing Crosby, a top movie star and singer, was astounded by the incredible sound quality and instantly noticed the huge commercial potential of the new machines. The live music was standard for American radio at the time and the main radio network did not allow the use of disc footage in many programs due to its relatively poor sound quality. Crosby does not like live broadcasts 39 weeks a year, preferring the casual atmosphere of the recording studio and the ability to maintain the best parts of a show. He had asked NBC to let him pre-record the 1944-45 series on the transcription disc, but the network refused, so Crosby had resigned from live radio for a year. ABC agreed to let him use transcription disks for the 1946-47 season, but listeners complained about the quality of his voice.
The Mullin recorder came right at the right time. Crosby realizes that the new technology will allow him to record his radio show with sound quality that matches the live broadcast, and that this recording can be played multiple times without any significant loss of quality. Mullin was asked to record one show as a test and was soon hired as chief engineer of Crosby to re-record the rest of the series.
Crosby's inaugural season on October 1, 1947 was the first broadcast of a magnetic tape in America. He became the first American music star to use recordings for pre-recorded radio broadcasts, and the first to master commercial recordings on tape. The Crosby radio show, recorded painstakingly, was edited through ribbon connections to give them unprecedented speed and flow on the radio. Mullin even claimed to have been the first to use "canned laughter"; at the urging of Crosby's chief writer Bill Morrow, he entered the laughter segment from the previous show into a joke on the next event that did not go well. Soon other radio players demanded the ability to record their broadcasts with high recording quality, and the ban on recording was revoked.
Interested in using the new recorder as soon as possible, Crosby invested $ 50,000 of his own money into the California electronics company Ampex, and the concerns of six small people (led by Alexander M. Poniatoff, whose initials were part of the company's name) soon became world leaders in record development, revolutionized radio and recorded with the famous 200 Model tape deck, was released in 1948 and developed directly from Mullin's modified Magnetophons.
Ribbon tape on BBC
The BBC acquired several Magnetophon machines in 1946 experimentally, and this was used in the early stages of the new Third Program to record and replay opera performances from Germany (life relays became problematic due to the unreliability of landlines in the immediate post-war period).
These machines were used until 1952, although much of the work continued to be done using established media; but from 1948 new British models became available from EMI: BTR1. Although in many ways awkward, the quality is good, and since it is impossible to get the Magnetophons anymore, it is an obvious choice.
In 1963, the Beatles were allowed to upgrade their recordings on the BBC with overdubbing. The BBC does not have multi-track tapes. They will copy it to another cassette.
In the early 1950s, EMI BTR 2 became available (right); machines that are much better and generally preferred. It became the standard in the recording channel (space) for many years, and was used until the late 1960s.
The engine is responsive, can run at fast enough speed, has a light touch operation button, front facing head (BTR 1 has rear facing head which makes editing difficult), and quick and easy to do best editing on.
The recording speed is finally standardized at 15 ips for almost all work in Broadcasting House, and at 15 ips for music and 7 ½ ips for a speech at Bush House. Broadcasting House also uses EMI TR90 and Philips engines that are lightweight but very easy and fast to use: Bush House uses several Leevers-Rich models.
The range of the machine studers had become the standard of the studio recording industry well in the 1970s, and gradually replaced the old BTR2 in the recording and studio rooms. In the mid-2000s tape was quite well used and has been replaced by a digital playout system.
Standard products
Working with Mullin in the United States, Ampex quickly developed two-track stereos and then three-track recorders.
Professional audio tape recorders in the early 1950s used / 4 in broad band (6 mm) on 10 1 / 2 in rolls (27 cm), with a capacity of 2,400 feet (730 m). The typical velocity initially 15Ã ± s (38.1 cm/s) yields a 30 minute recording time at reva 2,400Ã, ft (730Ã, m). 30 di/s (76.2 cm/sec) is used for work of the highest quality. Domestic and portable recorders use 7, 5 or 3 inch (18, 13 or 8 cm) inch reels (or spools). Early professional machines use single-sided coils but two-sided coils soon became popular (especially for domestic use). Tape rolls are usually made of transparent plastic but metal rolls are also used.
The standard ribbon speed varies by a factor of two - 15 and 30 in/sec used for professional audio recording; 7 in/s (19.1 cm/sec) for the audiophile initial recording tape; 7 1 / 2 and 3 3 / 4 in/s (19.1 and 9.5 cm/sec) for audiophile and consumer recordings (usually on 7 inch (18 cm) rolls. 1 in/s (4.8 cm/sec) and sometimes even 15 / 16 di/s (2.4 cm/s) is used for voice, dictation, and applications where very long recording time is required, such as call logging police and firefighters.
The standard 8-track ribbon, promoted by Bill Lear in the early 1960s, popularized the consumer's car audio playback. Finally, this standard was replaced by a smaller and more reliable Compact Cassette.
The development of Philips Compact Cassette in 1963 and the development of Sony Walkman in 1979 led to extensive use of magnetic audio tapes widely. In 1990, Compact Cassette was the dominant format in mass market music recordings. The development of the Dolby noise reduction technology in 1960 brought the audiophile quality recording to the Compact Cassette also contributed to its popularity.
Next development
Since their first introduction, analog cassette recorders have undergone a series of long progressive developments that result in improved sound quality, ease, and flexibility.
- Two tracks and, then, multi-track heads allow discrete recording and playback of individual sound sources, such as two channels for stereophonic recording, or different microphones during live recording. More versatile machines can be shifted to record on multiple tracks while playing other tracks, allowing additional tracks to be "set" in sync with previously recorded material such as a rhythm track.
- The use of separate heads for vs. recording. playback (three total heads, counting eraser head) activated monitoring of the recorded signal a split second after recording. Mixing back the playback signal to the recording input also creates a primitive echo generator.
- Dynamic range compression during recording and expansion during playback extends the available dynamic range and improves the signal-to-voice ratio. dbx and Dolby Laboratories introduced additional products in this area, initially for studio use, and then in versions for the consumer market. In particular, noise reduction of "Dolby B" becomes very common in all the cheapest tape recorders.
- Computer-controlled analogue tape recorder was introduced by Oscar Bonello in Argentina. Mechanical transport uses three DC motors and introduces two new advances: automatic microprocessor transport control and bias adjustment and automatic response frequency. Within 30 seconds, the recorder adjusts its bias for minimum THD and the best frequency response to match the brand and the magnetic tape batch used. The microprocessor transport controls allow a fast location of any point on the recording.
Operation
Electricity
The electric current flowing in the tape headband creates a fluctuating magnetic field. This causes the magnetic material on the tape, which travels through and comes in contact with the head, to align in a manner proportional to the original signal. The signal can be reproduced by running the recording on the head of the tape, where the opposite process occurs - the magnetic trace on the band induces a small current in the read head that is close to the original signal and then amplified for playback. Many tape recorders can record and play back at once by recording and spinning heads separately in queues or combined in one unit.
Mechanical
Modern professional recorders usually use a three-motor scheme. One motor with a constant rotational speed pushes the winder. This, usually combined with pinchy rubber rolls, ensures that the tape speed does not fluctuate. Two other motors, called Torsi Motors, apply the same torque and are opposite to the supply and take the reels during the recording and play back the function and maintain the tape tension. During a fast winding operation, the pinch roller is removed and the take-up reel motor is supplied with a higher voltage than the supply motor. The cheapest model uses a single motor for all required functions; the motor moves the rollers directly and the supply and take-up rolls loosely coupled to the rolling motor with the belt or the grip slipping. There is also a variant with two motors, in which one motor is used to play back only.
Limitations
The storage of analog signals on the tape works well, but it is not perfect. In particular, the granular properties of magnetic materials add high-frequency sound to signals, commonly referred to as tape hiss. Also, the magnetic characteristics of the tape are not linear. They exhibit a typical hysteresis curve, which causes unwanted signal distortion. Some of these distortions are resolved by using high-frequency AC bias signals that are not audible while recording, although the amount of bias requires careful adjustment for best results. Different ribbon materials require different amounts of bias, which is why most recorders have a switch to choose this (or, in a cassette recorder, switch automatically based on the cut in the cassette shell). In addition, systems such as Dolby's noise reduction system (Dolby B, Dolby C, Dolby S and Dolby HX-Pro) have been designed to correct some noise and distortion problems. Variations in the speed of the tape cause flutter, which can be reduced by using double capstan. The higher speeds used in professional recorders tend to cause "head bulges," which are fluctuations in low frequency responses.
Various tape recorders
There are a wide variety of cassette recorders available, from small handheld devices to large multitrack machines. A machine with built-in speakers and audio power amplifiers to drive them is usually called a "tape recorder" or - if it does not have a recording function - "cassette player," while those requiring external amplification for playback are usually called "tape deck" (regardless of whether it can record).
Multitrack technology enables the development of modern art music and one artist, Brian Eno, describes the tape recorder as "an automatic musical collage device".
Usage
Magnetic tape brought great changes in the radio and recording industry. Sound can be recorded, deleted and re-recorded on the same band over and over again, the sound can be duplicated from recording to a cassette with only a slight loss of quality, and the recording can now be edited with great precision by trimming the tape physically and rejoins. In August 1948, Los Angeles-based Capitol Records became the first record company to use the new process.
Within a few years after the introduction of the first commercial tape recorder, the Ampex 200 model, launched in 1948, the inventor of the American musician, Les Paul, had invented the first multitrack tape recorder, which brought another technical revolution in the recording industry. The tape made possible the first real sound recording made by electronic means, paving the way for bold sonic experiments from the Musique ConcrÃÆ'¨te school and avant garde composers such as Karlheinz Stockhausen, which in turn led to the recording of innovative pop artist studios such as Frank Zappa, The Beatles , and The Beach Boys.
Tape enabled the radio industry for the first time to record many parts of the program's content such as advertisements, which had previously been presented directly, and it also enabled the creation and duplication of complex recordings, with great precision, long duration of the entire program. It also, for the first time, enables broadcasters, regulators and other interested parties to conduct a comprehensive recording of radio broadcasts for legislative and commercial purposes, leading to the growth of the modern media monitoring industry.
Innovations, such as multitrack recording and echo recording, allow radio programs and advertisements to be pre-produced to levels of complexity and sophistication that were previously unattainable and the recording also caused significant changes to the tempo of the program content, thanks to the introduction of endless-loop tape cartridge.
Although they are primarily used for sound recording, tape machines are also important for data storage before the advent of floppy disks and CDs, and are still used today, although mainly to provide offline backup to hard disk drives.
Tapedeck speed
Professional decks will use higher ribbon speeds, with the most common 15 and 30 inches per second, while lower ribbon speeds are typically used for smaller recorders and cassette players, to save space where loyalty is not as important as professional recorders. By providing a variety of ribbon speeds, users can trade the recording time of signal quality with higher band speeds thus providing a greater frequency response.
There are many speed recordings used in all types of cassette recorders. Speed ​​can be expressed in centimeters per second (cm/s) or in inches per second (in/second).
Cassette format
See also
- Audio editing
- Audio band length and thickness - Details of various audio cassette formats.
- Digital Audio - History of digital audio usage in commercial recording
- Digital voice recorder
- Electromagnetism
- Electronic music
- Voice recording history - Magnetic recording - Magnetic tape in the context of voice recording history.
- Multitrack recording - Use of sophisticated advanced cassette recorder.
- Preservation of magnetic recording
- Recorded reel-to-reel audio tape - Detail of old style recorder usage.
- Voice followers - For movies
- Sound recording and reproduction
- Video recorder
- Voice-Laboratory Volta Records
- Wire recordings
References
- This article incorporates text from the National Museum Bulletin of the United States, government publications in the public domain.
External links
- Magnetic Sound Recording Museum
- Tape Recorder - Interactive Java Tutorial National High Magnetic Field Laboratory
- WikiRecording Guide for the Analog Band
- Schedule development of magnetic recording.
- BBC/H2G2 Magnetic Recording History
- Selected History of Magnetic Recording
- Walter Weber's Technical Innovations at Reichs-Rundfunk-Gesellschaft
- Timeline from U of San Diego's Archive
- History of Recording Technology (WayBack Machine)
- Magnetic Band History (WayBack Machine)
- Description of the recording process with a diagram. pg. 2, pg. 3, pg. 4, pg. 5.
- Recording on the BBC - a brief history of the various sound recording methods used by the BBC.
Source of the article : Wikipedia
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