# How Turntables Work How a record player turns the wiggles in a groove into an electric signal and then into sound, from the spinning platter to the speaker\. By vivid\-wombat\-9d0c9ec9 Topic: Art, Music & Film [Open the interactive Jig](https://ask.jig.com/j/aMin3C4H9wkQ) ## Transcript ### 1. How Turntables Work A record player turns a wiggly groove into music, with no computer at all\. Let's follow the sound from the spinning record to the speaker\. Drag anywhere to look around\. This turntable is modelled on a classic direct\-drive DJ and hi\-fi deck\. ### 2. A steady spin The heavy metal disc under the record is the platter\. Magnets on its underside sit just above a ring of copper coils\. Electricity switches from coil to coil and pulls the magnets round, so the motor turns the platter directly\. At 33⅓ turns a minute, the platter goes round once every 1\.8 seconds\. Seven\-inch singles use 45\. ### 3. One long spiral A record side holds a single groove\. It starts near the edge and spirals inward toward the label, like a track around a hill\. Here the spiral is drawn far wider apart than the real one\. An LP side plays for about 22 minutes\. Its groove runs from about 146 mm to about 60 mm from the centre\. ### 4. Lower the needle The tonearm carries the needle, called the stylus\. The cue lever lifts the arm, swings it over the edge and lowers it gently into the groove\. The counterweight at the back sets how hard the stylus presses\. The stylus presses with about 2 grams, the weight of a paper clip or two\. ### 5. Riding the wiggles This giant model shows a tiny piece of groove, made about a thousand times bigger\. The groove walls wiggle in the exact shape of the sound wave\. The diamond tip rides between them and is pushed from side to side\. A real groove is narrower than a human hair\. Each of its two walls carries one stereo channel\. ### 6. Wiggles become electricity The tip sits on a thin rod called the cantilever\. A tiny magnet on its far end shakes between two coils of wire\. A moving magnet makes electricity flow in a coil, so the wiggles turn into a small electric signal\. This kind of cartridge makes only a few thousandths of a volt\. It needs no power to do it\. ### 7. Following the spiral As the record turns, the groove itself pulls the stylus slowly inward\. The whole arm swings in a gentle arc from the edge to the label\. Press play to watch a whole side in a few seconds\. The record always turns at the same speed, so the groove passes the stylus at about 50 cm a second at the edge but only about 20 near the label\. ### 8. From groove to speaker The tiny signal travels through the arm and a cable to a phono preamp, which makes it much stronger and balances the bass and treble\. An amplifier then drives the speaker cone back and forth, and those wiggles become sound you can hear\. The preamp undoes a standard tone shaping used when records are cut, called the RIAA curve\.