A tape recorder is an apparatus for recording sounds on a magnetic tape which can be wound in a spool or cassette .
The name Magnetophone was originally a trademark registered by AEG ( Telefunken ) and IG Farben and designated the only true “tape recorder”. This term has passed into everyday language, becoming a kind of common name.
The principle of the tape recorder is to polarize, by means of an electromagnet (magnetic head), the magnetic metal particles of a flexible ribbon support, running at constant speed over the head.
History of the Tape Recorder
The magnetic recording was invented in 1877 by the American engineer Oberlin Smith.
The first practical experiments date back to the telegraphy of the Danish engineer Valdemar Poulsen in 1898. Four periods mark the evolution of these techniques: mechanical, electromechanical, magnetic and finally, electronic.
In a first period, the tape recorders are not magnetic, but mechanical; there is simply a deformation of a material support, the acoustic energy transformed into mechanical energy serving directly for etching. At that time, the process was envisaged only as a substitute for shorthand, and therefore intended by its inventors to safeguard political texts and speeches.
In 1857, Édouard-Léon Scott de Martinville came up with the phonautograph, which was a camera recording acoustic vibrations on to coated paper soot.
Phonograph with cylinder
In 1877, the safeguarding of sound was effected by the permanent deformation of a material support. It then allows for its restitution. Charles Cros (who described the principle) and Thomas Alva Edison (who implements it) developed Paleophone 3 and the phonograph, respectively, using wax-covered rollers.
Ten years later, in 1887, Emile Berliner, an American technician of German origin, succeeded in developing the gramophone (where it replaces the rolls with a disc) and thus brought a definite improvement to the idea of Charles Cros.
At this time, the recordings become electric. The acoustic energy is first transformed into electric power that can be manipulated and amplified in order to operate the burin burner with greater sensitivity and precision.
In 1920, to produce the first electrical sound recording (electrical or Orthophonic recording), Lionel Guest and Horace Merriman use an amplifier with triode for burning.
In 1925, similar work was undertaken at Bell Laboratories by JP Maxfield and HC Harrisson.
Thanks to the unification by Maxwell and Ampere, around 1820, of the laws of electricity and magnetism in electromagnetic theories, and thanks to the discovery by Heinrich Hertz of these same electromagnetic waves in 1887, the recording could become magnetic once again thanks to the preservation of a remanent magnetization proportional to the intensity of the electric field of the electromagnet, even after removal of this field.
Magnetic Wire Telegraph
As early as 1888, the American, Oberlin Smith, proposed a method of recording sounds by magnetizing a wire. Recording is done by placing an electric battery between the telephone microphone and the magnetic head. Reading is done by connecting a telephone headset directly to the magnetic head.
It was not until 1898 that Valdemar Poulsen built his telegraphone, a machine capable of recording sounds on soft wire, on iron discs, and on soft iron strips.
These three versions will be built by Mix & Genest, who soon lose interest in the project.
The telegraph has had some success in America where it is built and marketed by the American Telegraphone Company.
Although the machine works relatively well with regard to its simplicity, it does not offer sufficient recording quality and is limited to diction.
The German company Max Kohl perfected it in 1921 by adding a very rudimentary amplifier using a triode lamp: the recording is done on magnetic disk.
A few years later, an improved version was born in America: the Record-O-Phone, to which a tube amplifier can be attached for better hearing.
Magnetic Tape Recorder
In 1928, the German Fritz Pfleumer made the true ancestor of the tape recorder. Working in a cigarette manufacturing company, he developed a strip of fine paper covered with iron powder.
His machine uses a tube amplifier and AEG bought the patent in 1930. AEG then embarked on an extensive program of research and development on magnetic heads, tape transport mechanisms and amplifiers to perfect his tape recorder. At the same time, work on the magnetic stripe was carried out at the IG Farben plants in Ludwigshafen (now BASF ).
At the beginning, the strips were made of paper. They are 5 mm wide and run at 1 m / s . The quality is still mediocre and breaks are common. In 1932, AEG expanded the band to 6.5 mm and decided to work on a new, stronger support: the first acetate bands were born in 1934. They are covered with carbonyl (Carbonyl Iron). The size of the particles does not allow quality recordings, and the DC pre-magnetization makes the medium very linear. The few musical recordings are of a disastrous quality.
IG Farben perfected the band in 1936 by replacing the carbonyl with iron oxide Fe3O4 which was black in color. The scrolling speed is reduced to 77 cm / s (which the Americans will round off in 1945 at 30 inches per second, or 76.2 cm / s ). It was not until 1939 that the brown iron oxide Fe 2 O 3 was used for better sound quality. High fidelity will only be possible in 1941 with the use of high-frequency pre-magnetization (although discovered in the 1920s, it will remain ignored until a recorder produces records of unsurpassed quality: pre-magnetization with direct current had oscillated).
Tape Recorders and the Nazis
Adolf Hitler and his relatives will make extensive use of the tape recorder for their radio speeches: public speeches like those of the Reichstag were systematically recorded. Others were pre-recorded and broadcast from the studios after the speaker left the premises, thus defeating any attempt. The quality of the amplitude-modulated radios of the time ( 4,500 Hz bandwidth ) rendered the sound of the tape recorder indistinguishable from that of him speaking directly.
First Classical Concerts Recorded
As early as 1939, AEG worked on a head with two air gaps to record two tracks on the same band. Initially, it is only to record the same signal in push-pull, but this method does not succeed. The first stereophonic recordings were made in 1942. Most of the concerts were recorded as early as 1941, of which more than 250 were recorded in stereo.
In 1945, the Russians seized about 50,000 bands of all kinds, of which only a little more than a thousand were returned to Germany in 1991. Among them, there are a number of public concerts directed by Furtwängler, Karajan, Knapertsbuch, and more than 600 bands of lieder (Schubert, Schumann, Mahler) with Michael Raucheisen on piano.
Here is a very early Beethoven recording, where the quality is surprisingly high.
Extension To The General Public
Tape recording became widespread as early as 1946 in America where Bing Crosby made his shows on tape before engraving on disk diffusion. Ampex will dominate the market for several decades. The first tape recorder sold to the public in 1947 is the Brush’s Soundmirror BK-401, which also produces its own tapes, initially made of paper and then made of plastic. Scotch launched in tape in 1948 with tape Type 100 (paper) followed by 101 (plastic).
History of the VCR
As early as 1950, the Americans worked on a method of recording the television image on tape. The VERA system is functional, but too greedy in terms of the amount tape need.
It is Ampex which will produce the first video tape recorder 2 inches (quadruplex system). The machine will be functional as early as 1956 and will even register in color as early as 1957.
The phonographic industry will also use the tape recorder to replace the wax patches that did not allow for any editing. The companies Deutsch Grammophon and Telefunken will be the first to use the AEG tape recorders to record their 78-turn discs (and later microphones).
France will start using tape recorders for radio in 1948 and tape recorders will begin to attract audiences in the early 1950’s.
Nagra Portable Crank Handle
In 1951, the Nagra I, miniature lamps and crank winding, was the first very small (1/4 inch) magnetic tape recorder (30 x 18 x 10 cm) and revolutionized the recording of radio reportage.
The Nagra climbs to the highest level accompanying an expedition on Everest and sinks into the depths along with the bathyscaphe of Professor Piccard.
In the early years, amateurs used their tape recorder more to record their family affairs than to record a record or radio (what the novices did sometimes by microphone in front of the loudspeaker with very little sound fidelity, lamps with few connection sockets to a tape recorder).
How A Cassette Tape Recorder Works
A cassette tape recorder had a central device in which the tape was made to pass from the transmitting coil, consisting of a left-hand guide, a head for erasing any previous recordings, a head a recording head, a recording head (or a single recording / playback head), a driving assembly carried out by the capstan on one side, a rubber roller performing the pressure on the other, and a straight guide, before joining the take-up spool.
Each of the two spools was held by a small central spindle with 3 triangular spikes, arranged on a small circular horizontal support plate (unlike a 78-spindle or micro-spindle disk, the central cylindrical spigot and simple adhesion and weight (except soft discs) on the non-smooth surface of the tray was sufficient) to ensure rotation of the take-up spool, the speed of the belt being controlled by that of the capstan, as well as that of the transmitter and receiver for fast winding or rewinding.
In order to pass the magnetic side of the strip on the side of the heads, and not the other way round, the strips being brown on both sides (color of iron oxide) and then dark brown in the 1970’s, of spotting was the frosted aspect on the magnetism side, and shining on the other side.
In order to maintain sufficient band tension on the left and right transmitting and receiving coils, a motor drives the take-up spool forcefully at a slightly higher speed than the maximum rotational speed, as well as the slightly revolving transmitter.
The coils were plastic or metal, and similar to movie projectors 8 mm . The most common diameters were 8 cm ( dictaphones and portable mobile equipment), 13 cm (mobile portable equipment), 15 cm and 18 cm (domestic equipment) and 27.5 cm (professional equipment). The typical length of a 13 cm diameter coil was 1 hour .
The amateur recorders were placed horizontally, initially with 13 cm reels, then up to 18 cm from the 1960s, and often vertically from the 1980s, with 26 cm reels, which were much easier to handle.
The first devices were tube, monophonic twice a track, then stereophonic, and gradually “transistorized” on integrated circuit boards.
Adjusting the Magnetic Heads
The positioning of the heads was adjusted and calibrated at the factory so as to be perfectly rectilinear, but it was often the case on the amateur recorders that there was an angular offset between the original recording and the reading giving an “oblique” signal and especially a phase shift between the two stereo signals, giving clipping and distortion, especially if they were subsequently monophonized, appearing first by a loss of treble (but which could be compensated by a tuning screw, which was adjusted to the ear on the sharpness of the treble).
The tape and cassette tape recorders had a number of shielded cable connectors (sold in shops, but also in kit that can be welded by the operator):
A microphone plug, 2-pin DIN (signal + ground), then 3-pin (dual stereo microphone), then large format jack since the 1980’s.
A connection socket to a HIFI or other compatible device, input / output (recording or playback), DIN 3-pin mono then DIN 5-pin stereo, then 4 American RCA since the 1980’s. A listening jack for control over headphones, large format jack or small format.
The transition from DIN to RCA in the 1980’s introduces a difference in impedance compatibility, with the recording becoming weaker, and an upgrading of the devices was required by the operator.
The recording volume was adjusted by a button, then for some tape recorders a slider or rotary potentiometer, associated with a control galvanometer called “vu-meter”:
Recorded above a certain volume, the magnetic oxide particles could no longer deviate further, and saturated. This saturation can also exist on a microphone, the width of the groove being limited, as well as on a CDR or mini-disc.
Recorded at too low a volume, it required “pushing” the playback volume, which also amplified the band blast.
The first amateur tape recorders indicated the volume recorded on the tape using, until about 1965, as in lamps, a “magic eye”, which retracted more or less, until disappearing completely at saturation with the optimum volume being at the retraction limit).
Both the left and right channels, 2 needle galvanometers, using a green zone, used a yellow “best efficiency zone” (better signal-to-noise ratio) and a red zone indicating the saturation of the recording of the magnetism of the bands.
Until the 1970’s, only the volume of recording was indicated by the galvanometers, then in the 1980s they also displayed the volume recorded at the time of reading.
A few appliances used “leds” indicators from the 1990s.
Removing Clocks and Snoring
Other improvements include the switching noise known as “clocks”, which is spurious in a fraction of a second, caused by the lighting and extinguishing of the red lights signaling the opening and shutting of the microphones, particularly in the studios broadcasting (and on their doorstep the prohibition to enter), very clear on the direct but attenuated by the addition of capacitors, or on the first magnets to reels (and cassettes) until the beginning of the Sixties.
At the start and stop of the recording, audible in reading, by the sudden pressing of the magnetic head and the reaction of the electronic circuits, and then possibly the same sudden stop (unless using the “pause” , rather than “stop”),which the manufacturers succeeded in mitigating, and then disappearing completely over the years on all tape recorders.
The possible slight “snoring” of the sector in the background at 50 Hz, in recording and / or reading, due to the lamps of the tape recorders of the 1950s (as on tube stations) disappeared with transistorization and progress low frequency “filters”.
Recording and Playback Times
From the “standard” thickness of the strips, the quality of the supports made it possible to progressively reduce this thickness, so as to propose, from the 1960s, durations up to 4 times greater than those of origin for the same speed (which was also the case of cassettes, ranging from C30 (2 times 15 min) to C180 (2 times 90 min)).
At a speed of 19 cm / s (7.5 “/ s), called” fast “at the time by the” amateurs “, on a reel of 18 cm , on the total of the two recording directions and in stereophony , the durations (as indicated on the housing boxes) were approximately:
- Standard time (360 m): 1 hour
- “Long” duration (540 m): 1 hour 30
- “Double” duration (720 m): 2 hours
- “Triple” duration (1080 m): 3 hours
- “Quadruple” duration (1440 m): 4 hours
The above durations are depending on the scrolling speed.
These times also being inversely proportional to the speed of travel, and proportional to the length of the belt, and therefore to the square of the diameter of the coil (less the approximately proportional diameter of the central hub) , with respect to 19 cm / s (7.5 “/ s) (fast speed) :
- Multiplied by 2 to 9.5 cm / s (3.75 “/ s) (average speed)
- Multiplied by 4 to 4.75 cm / s (1.87 “/ s) (slow speed)
- Divided by 2 to 38 cm / s (15 “/ s) (” Professional “speed)
- Multiplied by 8 to 2.37 cm / s (0.94 “/ s) (adopted on Uher laptops for conferences)
These speeds are depending on the diameter of the coils.
In the same way, these durations could be compared to a coil of 18 cm:
- Multiplied by 2 for a 26 cm reel
- Divided by 1.5 for a 15 cm reel
- Divided by 2 for a 13 cm reel
Monophonic or Stereophonic
Of course, on 4-track stereo tape recorders (2-way playback), recordings made in single monophony could, by being recorded on each track, multiply by 2 the duration.
The tapes could be returned at the end of recording to ensure a second session (some tape recorders were even self-reversing at the end of tape). The same bands were used for full track recordings, 2 tracks and 4 tracks , but the recordings were obviously not compatible. One of the tracks recorded on a 2-track recorder was played lower on a 4-track.
Conversely, a 2-track tape recorder playing a 4-track recording gave an inaudible result, consisting of the mix of the two tracks at the location and the other two tracks of the adjacent piece in reverse, unless only 2 of 4 tracks were initially recorded.
Advantages and Disadvantages of Long Durations
Note that when the durations are increased, they have certain advantages:
- Saving the recording time on the same medium, combined with space saving
- Obligation to change face or coil less frequent,
- Reduced rewind time to search for recording at lower speed,
- Magnetic smearing and less rapid friction wear of heads at low speed
But in return have several disadvantages:
The finer the band, the more fragile it is, increasing the risk of fracture, twisting and tangling, especially during fast winding or rewinding.
Below a certain thickness, the reduction of the “deep” bass spectrum (20 to 60 Hz) is required to reduce the magnetic layer a little to manufacture.
Proportionally larger purchase price, as these bands are more difficult to manufacture.
A crying on certain magnets at the end of the band at “fast” speed, due to a “skating” between the capstan and the roller on a band that is too fine polyester, no longer being able to compensate for the inertia of a transmitting coil with a small central hub, almost empty and having to turn all the more quickly.
For slower recording (especially at 4.75 cm / s ):
Loss of fidelity in the sharpest treble (10 to 16 kHz), leaving better place for the blast or “white” noise of the band, due to the “sliding” of the strip between the roller and the end of the capstan.
In case of non-rectilinear azimuthing of the recording / playback head, multiplication by 2 or 4 of the clipping or even the distortion in the treble, from one magneto to the other.
Professional Tape Recorders
It goes without saying that professional tape recorders, especially for recordings recorded on discs or for broadcasting in public concerts, were of optimal quality:
“Full Track” for a monophonic or “2-track” recording for stereo recording, and even using much wider bands to perform the muti-track mounts before switching “Stereo” over the entire width of the band (not returnable, it has given in this case the music or the lyrics backwards …), are, of course “standard” thickness.
High speed recording: 15 “/ s (38 cm / s), or even 76 cm / sec (30” “/ sec)
“Open” coils on the upper side (not needing to be turned upside down), to minimize possible noise and static friction.
Azimutage perfectly adjusted in phase with 3 separate heads : Recording, reading, erasing.
The quality of the tapes and appliances improved over the years, and a “correct” recording at 9.5 cm / s and mediocre at 4.75 cm / s in the 1960s became almost 9.5 cm / s as good as 19 cm / s and correct at 4.75 cm / s in the 1980s. Amateur recordings, especially made with “inexpensive” (and without dolby) tapes or cassettes, were accompanied by a slight loss of treble, this loss added to each possible postponement, which was compensated by accentuating the treble to the listening, but also the breath.
Magnetic tapes have historically had two supports:
Acetate: This tape was inexpensive to manufacture, but withstood very poor mechanical stresses (sudden stop, for example), and forced to introduce delicate tape tension control mechanisms into the tape recorders. The risk of breaking bands remained high if different transmitter and receiver coils were used (due to the different inertia of the coils);
Polyester: More expensive to buy, it had a much better mechanical strength and finished in the 1970s by completely dethroning the acetate, relegated to the establishment of only “disposable” recordings.
In 1985, Maxell produced some 26 cm “chrome” magnetic tapes for a better quality of treble, but much more expensive than iron, and tape recorders with this setting were unlike cassette recorders, which were very rare and not compatible.
Comparison of Cassettes
It should be noted that cassette recorders adopted from the outset the standardized speed of 4.75 cm / s , using, moreover, bands about twice as narrow and twice as fine, and therefore even less theoretically faithful in quality, to succeed to be incorporated in these “mini-boxes”, but the technique had already progressed since, and continued to progress with the improvement of the acute by the strips called “Chrome” then “Metal”, and the reduction of the breath by the “Dolby” systems B, C then S.
Some larger cassettes were also manufactured for a few years, with the width and thickness of a band of coils and a speed of 9.5 cm / s for better sound fidelity (speed also used for convenience on some magneto- cassettes), but the “standard” cassette format, which is more practical, less cumbersome and has more recording capacity, has been constantly improving and has therefore become too busy for too many years commercially so that these cassettes are sufficiently interesting, moreover, they were in quality and duration, that the equivalent, more practical of use, but more bulky, of a reel of 8 cm.
The “quadruple durations” (as well as the C180 cassettes), which were too fragile, were only manufactured for a few years, and even triple durations (as well as C120 cassettes) were not recommended unless necessary for broadcasting purposes. example.
Maintenance of Magnetic Heads
The magnetic tapes always wear a little bit when passing the heads, depositing a thin layer of oxide on them, requiring regular periodic cleaning of the heads with a cloth or cotton swab impregnated with alcohol or a suitable solvent harmless, failing which the oxide was a screen leading to a progressive loss of acute.
It was sometimes necessary to also clean the main mechanical parts such as the capstan and the roller which could also be covered with oxide disturbing the speed.
Another small common defect is a sharp “grinding” caused by the rubbing of the old bands coming in “resonance” on the metallic guides, the latter appearing less on plastic guides of the cassettes, some of which cheap sometimes creaked at the winding.
When the heads were somewhat shifted in “depth” adjustment, or even the band deformed slightly over time, this slight offset could occur when listening between tracks, with the overflowing rear center track being added as a “Fading” where you could hear the basses slightly upside down superimposed on the desired tracks which they became a little weaker when listening.
Over time, old or even reused tapes, even if stored in good conditions of temperature and hygrometry, and protected from light, have become brittle, the oxide ending in decreasing, becoming sticky when winding to the next (even polluting and poison), sometimes resulting in an irregular volume of sound, then a permanent loss of the treble.
Analog Tape Conservation, Transfer, and Archiving
The INA, anxious to preserve valuable archives testifying to the preceding epochs, preserved for this reason (as it did for films, especially those called “flame” in celluloid!), by transferring them to more and more modern supports.
Reprints on CD of old recordings since the 1950s take back where possible the bands of origin (if not more and more, the microphones), by remastering them, fortunately these professional bands were originally an excellent quality, then carefully preserved.
As early as the 1960s, the strips were preceded and followed at each end by a frosted plastic stripe of about 60 cm (often green and red to identify the faces without inverting them), followed by a small band bonded to this leader tape preceding the magnetic tape.
Besides the advantage of being thicker to insert it in the receiver coil, it allowed to start the first piece and to finish the last one more precisely.
The tape recorders were then equipped with an automatic “stop” device, which, when passing through the metal band, stopped the assembly, avoiding that once the tape was completely terminated, the take-up reel and possibly the transmitting reel to rotate in a vacuum at high speed, which frequently happened before in the event of the operator not being monitored.
As with cassettes, when there was no longer enough tape on the transmitter coil to record a final new song, the operator would either let it cut “net” or “shunted progressively to” fading decrescendo “Or prefer to leave a” blank ” if he did not want a cut piece (the” cleanest “choice). Subsequently, the auto-reverse allowed the continuation of the entire piece, but with a mini-cut of a fraction of a second.
Mounting kits, with 2 rolls of green and red leader strips, a roll of metal strip, a roll of adhesive tape, a plastic guide and a cutter were sold frequently for amateurs.
It was common to perform entirely “manual” assemblies (similar to those performed for film films), by “marking” a mark on the bold pencil strip at the precise location of the connection, ( the support being clearly thinner and more flexible than a film film which used a special heat-dried adhesive ), is carried out by means of a longitudinal adhesive of 4 cm approximately.
This bonding was of course also used in the event of breakage of the strip, frequent on those in “acetate”, breaking much more easily, especially over time with heat.
On the other hand, editing has become practically impossible on the cassettes, too thin and small, editing by “carry” recording with very little loss of quality becoming preferable from the 1980’s.
The dissociation of the 2 tracks (4 with each side of tape) in separate mono, and so the Multiplay process, although feasible, did not exist on cassette tape recorders either.
All these assemblies have become extremely easy in recent years, with the emergence of digital and computing, by means of the most complete and practical editing software, many of which are accessible to amateurs.
Tracking high-speed tracks – It was common to spot a sequence or piece of music at high speed on the tape recorders remaining in playback (certainly very sharp) when rewinding front or back (this option was also offered in the “Cue” mode on cassette tape recorders ) .
Octave higher than double speed – It was also possible to “juggle” with the speeds, a recording performed at double speed taking a double frequency, thus located musically one octave above, and vice versa at half speed, thus allowing certain “tricks” in the sounds of a ” (which was also possible by changing the speeds of record players, but these did not have this ratio of “2”, except between 33 t 1/3 and 16 t 2/3 (1 octave), and close to 4/3 between 45 t and 33 t 1/3 (1 quarte) 6 ).
Many amateurs thus enjoyed themselves talking or singing in the family, having as a quick voice a “mouse” at double speed, or slow “bear” at half speed.
Repetitive announcements (made today by computer or CD) could also be done mechanically by running a very short loop around the reading set (special cassettes of this type were also made).
Superposition in “Rerecording Multiplay”
The “Multiplay” technique, available on some “modern” tape recorders on the Grundig tape recorder since 1967, also allowed: to record in mono with an instrument or a voice on track 1, then to carry it on track 2 by adding an instrument, then do the same with another instrument or voice on track 1, and so on, up to the equivalent of a major orchestra or choir performed by only one or a few people (which is also currently available on synthesizers).
Echo and Reverb
In the 1980’s, if the reading head was “downstream” of the recording head, the almost simultaneous reading (known as “Cue”) was possible during recording, allowing the result to be verified directly.
The “Echo / Reverb” mode was added, with a greater or lesser offset depending on the distance between the 2 recording and playback heads and the speed.
Some reissues of old monophonic recordings, even 78 laps, as in Pathé, used this method in the 1970’s, thus recreating a relief of “false stereo”, but this one too artificial and degrading a little the sound “Natural”, a real good “mono” was re-adopted later.
In the 1950s, many individuals and teachers discovered the thousand and one possibilities of magnetic recorders:
Specific in the pedagogical use of language learning, dictation, dance and music, private amateur, to record radio, records, family or sound editing their slides or amateur movies.
The market is then dominated by the following brands:
- Netherlands: Philips (which also manufactures tape recorders in France and Austria);
- Japan: the inescapable Sony , but also Akai and TEAC . The fleeting appearance of Dokorder in the 1970’s. More discreet manufacturers like Crown, Nivico (JVC), National are trying to establish themselves in the portable recorder market;
- Belgium: Acec, which launched Sonofil in the 1940s, launches the Lugavox range and the very original Carad R62, R53, R66 and R59 series;
- Norway: In 1970, Tandberg Audio, also a specialist in language laboratories, took over the cross-headed heads device, which contributed to the renown of Akai, recording synchronization beeps by a polarized ultrasonic signal in a magnetic head slightly offset from the recording head;
- Switzerland: Studer ( Revox ), Stellavox, Nagra ;
- West Germany: Braun , SABA , Saja (Sander & Janzen), Maihak, Grundig , Telefunken , AEG , Uher
- Germany (East): VEB Messgerätewerk Zwönitz;
- Czechoslovakia: Tesla;
- Poland: Unitra.
Portable Mobile Recording – Nagra Portable Recorder
Invented by Stephan Kudelski, Polish-Swiss of about twenty years, it quickly becomes synonymous with portable tape recorder for all professionals of the information. The Nagra mark comes from the Polish word, which means “it will record”.
Robust and quality-minded, Nagra will be the basic tool for journalists and the majority of film sound engineers. It will also be the machine of choice of explorers of extreme and instrumentation embarked, in particular for aeronautical research.
The Nagra are standardized to the standards of the studio machines and have many modules and accessories for specific needs, such as special inputs or cinema synchronization devices.
In the 4000, 4200 and 4400 series, without looking for the robustness of the Nagra, these 13 cm reels were very popular among amateurs. A Uher 4200 tape recorder is shown at the beginning of James Bond’s Thunderball movie . The CR124 will be the first cassette recorder standards HiFi DIN 45500 at the time. His successor, the CR210, will accept chrome cassettes.
- Stellavox (en) : Swiss manufacturer, specially oriented to the film industry.
- Nakamichi (in) : Japanese manufacturer.
- Studio recording [ edit | change the code ]
- France: Tolana, Bourdereau, Schlumberger / Digitec
- Germany: Telefunken / AEG
- Switzerland: Studer / Revox
- Japan: Sony , Otari , Fostex , Tascam
- US: 3M , Ampex , MCI (in) , Scully, Soundcraft
- Great Britain: Ferrograph, Brenell, Leevers-Rich
Evolution of Cassette Tape Players
In 1963 , the cassette launched by Philips more convenient to handle, will gradually replace the strips in the coils during the 1970’s, although the tape parallel magnetos continued throughout the time of the magneto-cassettes, as always remaining higher technically in quality, especially for professionals.
This miniaturization due to the cassettes with respect to the reels will allow to develop new devices of all sizes ranging from the compact walkman to sophisticated cassette recorders with 3 motors and 3 heads. Larger, the DC system supported by Grundig and Telefunken, will not impose itself despite its sound quality at the top start.
During the 1970s and 1980s, the Philips cassette became able to reproduce recordings of high fidelity, thanks to the appearance of bands with magnetic properties superior to iron, such as chromium in 1973, then metal in 1979; of the bottom pink noise reducers of the band, mainly the Dolby B in 1968, then Dolby C in 1980, the Dolby HX Pro in 1982 and Dolby SR in 1986.
Other types of tapes were quite ephemeral, such as the 8- track car radio cartridge in the United States, 4 x 2 tracks on endless but often jammed, and Sony’s Elcaset faithful, with a strip of 1/4 “to 9,5 cm / s , but arrived too late in 1976 and very expensive.
Switching from Analog to Digital
The arrival of digital in the 1980’s of greater flexibility, with the compact disc then the internal electronic memory players put the analog tape recorder back, although the listening and recording qualities of it remain superior.
Indeed, the bandwidth of the analog band can reach 50 000 Hz while the current digital formats are limited to 20 000 Hz . However, according to Shannon’s theorem , the sampling frequency must be at least twice the highest frequency to be sampled.
The end of the 1990s will see flourish ads for cheap sale of high-end Studer Revox tape recorders , their owners discovering that their PC equipped with a good sound card is even more convenient.
The tape recorders were used extensively by sound professionals, the best performers to deal with multiple tracks at the same time, making it possible to modify the sound balance during the mixing phase ), and in general fashion in the 1960s to 1990s for their portability.
Manufacturers have even extrapolated video recorders or video recorders and later camcorders .
The Digital Tape Recorder (DAT)
The tape recorder has also evolved and in the early 1990s it became the Digital Audio Tape (DAT) tape recorder and the ADAT multitrack recorder.
Studio Recordings – The digital tape recorder was used extensively by professionals to record commercial discs from the 1980s on:
The recordings were more and more recorded from digital tape recorders and sometimes engraved at half-speed for better fidelity, especially for classical music, bearing the label “DAA” or “DDA” (Digital- Digital-Analog (the analogue being the engraving on micro-chip)), then
For recording on compact discs , the label indicating on the disc and / or the booklet of the CD:
ADD (Analog-Digital-Digital): use of an analog recorder during recording sessions, then digital for mixing and / or editing and burning, or
DDD (Digital-Digital-Digital, the best of high fidelity): use of a digital tape recorder during recording sessions, mixing and / or editing and burning.
The same principle has been widely used for the recording of computer data by bit and byte, but with very different bands: those used for audio quality had to have as little hysteresis as possible.
Those used for the digital recordings had to have a high hysteresis, in order to differentiate as clearly as possible the states 0 of the states 1, the intermediate values being of no interest.
Replacement by hard disks and then computer memories – Since the generalization, from the years 2000, digital recording on hard disk , then on memory card, SSD ( solid-state drive ) or others, the tape recorder and the recording of digital data on magnetic tape have become obsolete.