Sunday, December 25, 2011

Record Turntable Work

Turntables are Translation Devices


A turntable functions as a means to translate patterns imbedded in the grooves of vinyl platters into audible sound. Sound or music previously recorded on digital or analog tape is transferred to a master disk from which all other copies will be pressed. For most of the 20th century until the 1980s, analog phonograph records were the predominant medium in which recorded music was sold. In the 1950s, the 12-inch 33-rpm long-playing record or "LP" was introduced as the highest-quality form of mass-produced recordings. Beginning in the early 1980s, the LP was phased out by the recording industry, and the all-digital compact disc took over the market. While it is generally understood that the CD outperforms the LP in terms of convenience, lack of background noise and absence of wear, relatively few people are aware that the LP's potential for sound quality is greater than that of the CD. After nearly going extinct in the 1990s, the LP record has begun to make a modest comeback because of its appeal to fringe markets.


Grooves Contain the Music


An LP record contains finely cut V-shaped grooves that run in a spiral pattern from the edge to a circular end groove near the center. When the master disk is made from the original master tape, the stylus of a "cutting head" translates sound vibrations into microscopic indentations and bumps on the sides of the V. The master disk is cut while rotating clockwise, with its stylus moving gradually inward from the edge. During playback of the vinyl copy on a turntable, the stylus (or "needle") reads these same variations in the groove and sends the vibrations to a cartridge that it is mounted on the turntable's tonearm. The cartridge translates the stylus movements into electrical impulses that are carried though wires in the tonearm to an electrical connection with an audio system's amplifier or receiver, and from there to the speakers.


Quality Turntable Playback Makes for Quality Sound


The LP can only reach its potential when the turntable and all other links in the chain are functioning at a high level. The quality of every part of the turntable must be superior, which can require a significant investment of money. The stylus must be clean and not worn out, the cartridge and tonearm must be of audiophile caliber, and the turntable itself must have a smooth-running and quiet mechanism. Vibration underneath the turntable must be minimized, since it can travel through the turntable's feet right to the ultra-sensitive stylus. The cartridge and tonearm must be properly aligned and balanced so that the stylus contacts the disk at just the right weight and without pulling toward the right or the left. To reduce extraneous noise, clean the LP with commercially available cleaners before each playback. Finally, all audio connecting cords must be properly inserted, and both the amplifier and speakers must be functioning properly and without distortion.







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