Magnetophon was the brand or model name of the pioneering reel-to-reel tape recorder developed by engineers of the German electronics company AEG in the 1930s, based on the magnetic tape invention by Fritz Pfleumer. AEG created the world's first practical tape recorder, the K1, first demonstrated in Germany in 1935 at the Berlin Radio Show. [1] [2] [3]
Later models introduced the concept of AC tape bias, which improved the sound quality by largely eliminating background hiss. The resulting reproduction was so great an advance on any existing recording method that even those well acquainted with the industry could not tell the recordings from live play. Adolf Hitler used these machines to perform what appeared to be live broadcasts from one city while he was in another. A cache of 350 of these tapes was released years later when they were found in Koblenz. [4]
Two later model Magnetophons were taken to the United States at the end of the war, having been found in Bad Nauheim. These included both the newer oxide-coated PVC tape developed by I.G. Farben (BASF division) as well as the AC bias system. The Army officer who tracked them down, Jack Mullin, would use these machines as the basis of his own designs, which he demonstrated to the San Francisco chapter of the Institute of Radio Engineers in May 1946, and later at the MGM Studios in Hollywood in October of that year. Attending the SF demo were Ampex engineers Harold Lindsey and Myron Stolaroff, who were inspired to design their own reel-to-reel recorder based on Mullin's modified Magnetophon. [5] Mullin's friend, Richard Ranger, had also designed his own take on the Mullinized Magnetophon called the Rangertone; however, a demonstration of that machine to Bing Crosby did not go well. Mullin then arranged for Crosby to experience a demonstration of the machine designed by Lindsey and Stolaroff: the Ampex Model 200A. Although an initial showcase of the Ampex machine was unable to demonstrate recording, the audio quality of its playback was good enough to get Crosby to agree to work with them. With Bing Crosby arranging financial support for start-up manufacturing, the Ampex 200A went into production and within three years most major recording studios had purchased one. [6]
The Magnetophon tape recorder was one of the first recording machines to use magnetic tape in preserving voice and music. At first, early Magnetophons gave disappointing results. One of the first concerts to be recorded on a Magnetophon was Mozart's 39th Symphony played by the London Philharmonic Orchestra, conducted by Sir Thomas Beecham, during their 1936 concert tour. The recording was made on an AEG K2 Magnetophon running at 100 cm/s. The tape used was the early black iron oxide Fe3O4 type. When Beecham and the musicians heard the playback, they were greatly disappointed with the distortion and noise on the recording. Although the original tape is now lost, the recording survived until the 1990s and has been transferred. Some other surviving tapes show a tendency toward overmodulation. [7]
Later in 1939, the Fe3O4 oxide was replaced by the Fe2O3 type, which gave a significantly better recording quality, so much that the formula became a worldwide standard until the 1970s when chromium dioxide tapes appeared.
Adding a direct-current bias to the record head gave some improvement, but in 1941, Hans Joachim von Braunmühl and Dr. Walter Weber, both engineers at the German national broadcasting organisation RRG (Reichs-Rundfunk-Gesellschaft), accidentally discovered the technique of high-frequency bias in which the simple addition of a high level (about 10X the maximum audio level) inaudible high-frequency tone resulted in a striking improvement in sound quality by effectively smoothing the magnetization of unused portions of the audio band. The discovery was made when a Magnetophon producing recordings of extraordinary quality was sent 'for repair'. The machine was found to have an oscillating DC bias amplifier. Magnetic media are inherently non-linear, but AC bias was the means whereby the magnetisation of the recording tape was made linearly proportional to the electrical signal which represents the audio component. The Magnetophon became a 'high fidelity' recording system because in so many respects, it outperformed gramophone recording (which was the 78 rpm system of the time).
Many speeches, concerts, and operatic performances were recorded. Since many of the recordings survived World War II they were later issued on LPs and compact discs. One of the more remarkable series of recordings took place at the Vienna State Opera House, also known as Wiener Staatsoper, in 1944, when the German composer Richard Strauss recorded many of his famous symphonic poems, including Don Juan, Till Eulenspiegel, and Also sprach Zarathustra, with the Vienna Philharmonic Orchestra.
AEG engineers made rapid strides in perfecting the system and had practical stereo recorders by 1943. Until 1945, about 250 stereophonic tape recordings were known to exist, including some Richard Strauss and Furtwängler. Only three of those recordings are known to still exist. This includes a performance of Beethoven's "Emperor" Concerto with pianist Walter Gieseking and the Berlin Reichssenders Orchestra conducted by Artur Rother. [8] This remarkable performance was later issued on LP by Varèse Sarabande. Later in 1993, the Audio Engineering Society (AES) issued a special CD for the 50th birthday of stereo recording. This CD not only includes the "Emperor" Concerto, but the two other stereo recordings known to exist: a Brahms serenade and the last movement of Bruckner's 8th Symphony conducted by Herbert von Karajan. Piano Library also issued the Emperor concerto, and Iron Needle issued the Bruckner recordings (catalog IN 1407). ArkivMusic released a CD of the concerto, as well a later recording Gieseking made of Beethoven's first piano concerto with the Rafael Kubelik and the Philharmonic Orchestra.
Magnetophon recorders were widely used in German radio broadcasts during World War II, although they were a closely guarded secret at the time. The Allies were aware of the existence of the pre-war Magnetophon recorders, but not of the introduction of high-frequency bias and PVC-backed tape. [9] Their intelligence experts knew that the Germans had some new form of recording system but they did not know the full details of its construction and operation until working models of the Magnetophon were discovered during the Allied invasion of Germany during 1944-45.
American audio engineer Jack Mullin acquired two Magnetophon recorders and fifty reels of magnetic tape from a German radio station at Bad Nauheim near Frankfurt in 1945. The allied forces were traveling through Germany during WWII when they first discovered the device. The Allies then handed the Magnetophon over to Mullin. [10] Over the next two years Mullin modified and developed these machines, hoping to create a commercial recording system that could be used by movie studios. American popular vocalist Bing Crosby, dissatisfied with the quality of existing radio network recordings was prevailed upon to invest in this development and would use the technology, as modified by Mullin and the fledgling Ampex company, to record his radio broadcasts in the more relaxed atmosphere of the recording studio, which was a significant break from the then-norm of live studio audience broadcasts. In 2008, at the 50th Annual Grammy Awards Ceremony, Ampex received the company's first Grammy Award for Technical Achievement, to honor their contribution sixty years earlier of the Ampex 200, which "revolutionized the radio and recording industries". Ampex 200 co-designer Myron Stolaroff was among the company's employees representing Ampex who accepted the award. [11]
Magnetophon became the generic word for the tape recorder in some languages including German ("Magnetophon"), Swedish ("magnetofon"), Czech, Polish (magnetofon), French (magnétophone), Italian (magnetofono - only for reel-to-reel), Romanian, Serbian, Croatian (magnetofon - only for reel-to-reel), Greek (μαγνητόφωνο - magnitofono), Russian (магнитофон - magnitofon), Bulgarian (магнетофон - magnetofon), Slovak, Spanish (magnetófono or magnetofón), Hungarian (magnetofon - commonly shortened to magnó), Finnish (magnetofoni - commonly shortened to mankka), Estonian (magnetofon - commonly shortened to makk), Lithuanian (magnetofonas), Latvian (magnetofons) and Ukrainian (магнітофон - magnitofon).
Magnetic tape is a medium for magnetic storage made of a thin, magnetizable coating on a long, narrow strip of plastic film. It was developed in Germany in 1928, based on the earlier magnetic wire recording from Denmark. Devices that use magnetic tape can with relative ease record and play back audio, visual, and binary computer data.
Tape bias is the term for two techniques, AC bias and DC bias, that improve the fidelity of analogue tape recorders. DC bias is the addition of direct current to the audio signal that is being recorded. AC bias is the addition of an inaudible high-frequency signal to the audio signal. Most contemporary tape recorders use AC bias.
An audio tape recorder, also known as a tape deck, tape player or tape machine or simply a tape recorder, is a sound recording and reproduction device that records and plays back sounds usually using magnetic tape for storage. In its present-day form, it records a fluctuating signal by moving the tape across a tape head that polarizes the magnetic domains in the tape in proportion to the audio signal. Tape-recording devices include the reel-to-reel tape deck and the cassette deck, which uses a cassette for storage.
Videotape is magnetic tape used for storing video and usually sound in addition. Information stored can be in the form of either an analog or digital signal. Videotape is used in both video tape recorders (VTRs) and, more commonly, videocassette recorders (VCRs) and camcorders. Videotapes have also been used for storing scientific or medical data, such as the data produced by an electrocardiogram.
Ampex Data Systems Corporation is an American electronics company founded in 1944 by Alexander M. Poniatoff as a spin-off of Dalmo-Victor. The name AMPEX is a portmanteau, created by its founder, which stands for Alexander M. Poniatoff Excellence. Ampex operates as Ampex Data Systems Corporation, a subsidiary of Delta Information Systems, and consists of two business units. The Silicon Valley unit, known internally as Ampex Data Systems (ADS), manufactures digital data storage systems capable of functioning in harsh environments. The Colorado Springs, Colorado, unit, referred to as Ampex Intelligent Systems (AIS), serves as a laboratory and hub for the company's line of industrial control systems, cyber security products and services and its artificial intelligence/machine learning technology.
Reel-to-reel audio tape recording, also called open-reel recording, is magnetic tape audio recording in which the recording tape is spooled between reels. To prepare for use, the supply reel containing the tape is placed on a spindle or hub. The end of the tape is manually pulled from the reel, threaded through mechanical guides and over a tape head assembly, and attached by friction to the hub of the second, initially empty takeup reel. Reel-to-reel systems use tape that is 1⁄4, 1⁄2, 1, or 2 inches wide, which normally moves at 3+3⁄4, 7+1⁄2, 15 or 30 inches per second. Domestic consumer machines almost always used 1⁄4 inch (6.35 mm) or narrower tape and many offered slower speeds such as 1+7⁄8 inches per second (4.762 cm/s). All standard tape speeds are derived as a binary submultiple of 30 inches per second.
A video tape recorder (VTR) is a tape recorder designed to record and playback video and audio material from magnetic tape. The early VTRs were open-reel devices that record on individual reels of 2-inch-wide (5.08 cm) tape. They were used in television studios, serving as a replacement for motion picture film stock and making recording for television applications cheaper and quicker. Beginning in 1963, videotape machines made instant replay during televised sporting events possible. Improved formats, in which the tape was contained inside a videocassette, were introduced around 1969; the machines which play them are called videocassette recorders.
The Digital Audio Stationary Head or DASH standard is a reel-to-reel, digital audio tape format introduced by Sony in early 1982 for high-quality multitrack studio recording and mastering, as an alternative to analog recording methods. DASH is capable of recording two channels of audio on a quarter-inch tape, and 24 or 48 tracks on 1⁄2-inch-wide (13 mm) tape on open reels of up to 14 inches. The data is recorded on the tape linearly, with a stationary recording head, as opposed to the DAT format, where data is recorded helically with a rotating head, in the same manner as a VCR. The audio data is encoded as linear PCM and boasts strong cyclic redundancy check (CRC) error correction, allowing the tape to be physically edited with a razor blade as analog tape would, e.g. by cutting and splicing, and played back with no loss of signal. In a two-track DASH recorder, the digital data is recorded onto the tape across nine data tracks: eight for the digital audio data and one for the CRC data; there is also provision for two linear analog cue tracks and one additional linear analog track dedicated to recording time code.
1-inch Type C Helical Scan or SMPTE C is a professional reel-to-reel analog recording helical scan videotape format co-developed and introduced by Ampex and Sony in 1976. It became the replacement in the professional video and broadcast television industries for the then-incumbent 2-inch quadruplex videotape open-reel format. Additionally, it replaced the unsuccessful type A format, also developed by Ampex, and primarily in mainland Europe, it supplemented the type B format, developed by the Fernseh division of Bosch.
The Pavek Museum is a museum in St. Louis Park, Minnesota, that has one of the world's most significant collections of vintage radio and television equipment. It originated in the collection of Joe Pavek, who began collecting unique radios while he was an instructor at the Dunwoody Institute in 1946. Students then were given old radios to disassemble, and Pavek was concerned about what might be destroyed in the process.
John Thomas Mullin was an American pioneer in the field of magnetic tape sound recording and made significant contributions to many other related fields. From his days at Santa Clara University to his death, he displayed a deep appreciation for classical music and an aptitude for electronics and engineering. When he died in 1999, he was buried with a rosary and a reel of magnetic tape. A 2006 documentary movie, Sound Man: WWII to MP3, was made about his life and contributions to sound recording.
Myron J. Stolaroff was an author and researcher who is best known for his studies involving psychedelic psychotherapy. He also conducted clinical studies that attempted to measure the effects of LSD, mescaline, and other drugs on creativity.
Sound recording and reproduction is the electrical, mechanical, electronic, or digital inscription and re-creation of sound waves, such as spoken voice, singing, instrumental music, or sound effects. The two main classes of sound recording technology are analog recording and digital recording.
Laurence Earl Crosby was the long-serving publicity director of his younger brother, Bing Crosby, a manager, a philanthropist, an inventor and an author. He was the eldest of Bing's six siblings.
The history of sound recording - which has progressed in waves, driven by the invention and commercial introduction of new technologies — can be roughly divided into four main periods:
Multitrack recording of sound is the process in which sound and other electro-acoustic signals are captured on a recording medium such as magnetic tape, which is divided into two or more audio tracks that run parallel with each other. Because they are carried on the same medium, the tracks stay in perfect synchronization, while allowing multiple sound sources to be recorded at different times.
Longitudinal Video Recording or LVR was a consumer VCR system and videotape standard.
The following timeline tables list the discoveries and inventions in the history of electrical and electronic engineering.
Gábor Kornél Tolnai was a Hungarian-Swedish engineer and inventor. He is best known for his inventions and patents for spinning machines, devices for the Swedish National Defense and several types of tape recorders.
Philco Radio Time was an old-time radio radio series starring entertainer Bing Crosby. The series ran over ABC Radio with episodes airing from October 16, 1946–June 1, 1949. The series also was syndicated for a period of time over the Armed Forces Radio Network.