How Turntables Work
How turntables work may seem simple at first glance, however, there is a complexity to the science involved. The table spins, a small needle rests on the record and plays the music, right? Not so much.
Turntables can turn with three basic styles: belt-drive; rim-drive and direct-drive. In a belt-driven turntable, there is a small belt that continuously turns the arm in a pulley-type fashion. Rim-drive turntables possess a small idler wheel that holds tight against the inner-rim of the vinyl. Direct-drives are the preferred turntables of DJs, as they provide a more competent motion with small gears turning the motor in the center of the turntable. The induction motor used on most turntables works more efficiently compared with other motors because the varying voltage used within a home or building will not directly effect the motor's speed. Whether the record is a 78.26 rpm, 45 rpm or 33 1/3 rpm speed, the needle must rely on the constant, relatively unchanging speed of the turntable.
Besides the motor, there is a distinct relationship between the stylus (needle) and the vinyl itself. A small needle, attached to an arm, sits gently upon the vinyl and reads the intricate lines and details that were pressed into the vinyl record. The arm--known as a tone arm--swings into the record with the music, keeping the needle against the vinyl at all times. Some turntables have an arm that will automatically lift and return to it's starting position when the record has ended, however, most turntables require the user to manually lift the arm off of the record and return it.
In the 1970s, DJs began using two turntables to mix two different records seamlessly together. The phenomenon was so appreciated the technique is still used today and growing in popularity. In the case of DJ turntables, a mixer is placed in between the two turntables which are plugged into the mixer via RCA cables. The sound system is also hooked up via the mixer. The most basic of mixers will have two channels—one and two for the left and right deck, respectively—and a crossfader. The channels control how much of a track is heard, while the crossfader is slid back and forth to control which track is playing more dominantly through the speakers. Despite the vast amount of gear and techniques today's DJs use, turntables are still preferred, whether in conjunction with a collection of vinyl records or a computer program such as Traktor or Serato. The aptly named "push-button" DJs have nothing when compared with the skill and sound of a record being graced with the light touch of a needle.