Analog Recording Analog recording is a technique used to store audio or video signals for later playback. The first analog recording demonstration was by Thomas Alva Edison in 1877. The Lumiere Brothers used analog recording for motion picture for the first time in 1894 John Logie Baird developed a system in the 1920’s for the storage of video signals on phonograph (gramophone) records, that he called Phonovision.
Examples of analog audio are • Gramophone record (vinyl) • Magnetic tape • Wire recording
Vinyl The basic technique for vinyl recording is achieved by dislodging the microphone diaphragm which transcribes into a wavy groove on a moving piece of vinyl. The needle on a gramophone traces the wave on the vinyl to reproduce the sound created. The typical approach in vinyl recording is to put a lot of music on one record. This is achieved by moving the vinyl at a slow speed and using a narrow groove. The practical limit was reached in the mid 1800s; 33 1/3 rpm (revolutions per minute). At that speed a 20kHz signal has a wavelength of 0.0004 inch. It is very difficult to pick up a wavelength smaller than .0004inches.
The most popular type of vinyl is low frequency vinyl. This is because the amplitude produced is proportional to the side-to-side velocity of the needle. At low frequency the cutter will not turn around as often as it does at high frequency. The low frequency content is deliberately reduced and has to be rectified by the bass boost in the playback system.
The LP (long play) vinyl disk is becoming less popular due to the growth of CD (compact disk) technology and digital recording.
Magnetic Tape Tape is a strip of plastic that has been veneered in material that is easily magnetized, usually iron oxide. The apparatus that spins the tape is called the “capstanâ€. The tape is held against the capstan and wound across three heads; the “erase headâ€, the “record head†and the “play headâ€. The heads are “C†shaped. Magnetic fields are created by a coil of wire at the gap of the “C†. A magnetic area is produced on the tape when a strong current is produced on the wire. The amount of magnetism is directly related to the amount of current. When the tape is moved, a series of magnetic spots are created. This all happens at the record head.
The equalization of the tape is varied according to speed of the tape, automatic on most decks but must be set manually on some tape decks. The noise of the system is limited by the by the fact that the width of a single track is a factor in the strength of signal that can be recorded. The number of tracks on a cassette depends on the width of the tape.
Like LPs, cassettes are decreasing in popularity due to the introduction and advancement of compact disks and DVDs in the case of VCR tape.
Wire Recording Wire recording is a type of analog audio storage recorded onto thin steel or stainless steel wire. The first recording of wire was done by Valedermar Poulsen and mainly used for telephone recording in the 1920s\30s. Wire recorders had a higher media speed than tape recorders.
Even in the modern day of the digital world many studio producers and professional musicians prefer to record with pure analog methods.
Analog recording:
Advantages and Disadvantages The advantages of Analog recording are: • The sound quality; it mimics how human hearing works. • Analog recordings are considered to be easier to mix. • Tape is known for its durability and stands the test of time greater than a compact disks.
The disadvantages of Analog recording are: • The sound quality is not as accurate as digital recording. • Less flexible in editing, mistakes cannot be edited out. • More expensive than digital recording. • Unlike analog, digital recording can be used easier in the home and software is easy to use in an amateur environment.
Resources
Wikipedia: "http://en.wikipedia.org/wiki/Analog_recording"