The needle is in fact two separate components known as the cartridge and the stylus. The stylus is the tiny metal tip that makes contact with the vinyl when reading the groove. If you were to examine a single groove in the vinyl using a microscope, you would notice thousands of tiny ridges. It is these ridges that the stylus bounces over creating vibrations that will later be converted into electrical impulses and then sound.
The stylus connects directly to the second component known as the cartridge. The cartridge can easily be identified as the section where the wires (usually 4) connect or as the main body of the unit. To provide support and protection the cartridge fixes directly to the headshell (the large housing unit or metal roofing).
The most commonly used cartridge today is probably the STANTON 500AL. This cartridge provides a high quality sound output and is reasonably priced. If you are a DJ that performs more scratches, Stanton has a wide variety of needles that are almost skip proof and prevent vinyl hopping. More specialised styli can be brought with different shaped tips. The normal tip featured on most styli is rounded (or spherical). There is nothing wrong with this shape as it works perfectly well for beatmatching and scratching. The next stage up is the elliptical tip. The idea behind this shape is that when vinyl are produced they are cut with an elliptical needle therefore an elliptical stylus should in theory fit the groove like a glove. This type of needle should be good enough for anybody but if you really want to show off or have excess money to burn then go for the hyper elliptical stylus. The more expensive needles do provide a better sound if you are really looking for that full sound. You get what you pay for!
Other designs of styli manufactured by STANTON and ORTOFON do away with the headshell all together creating an all in one component consisting of stylus and cartridge which connects directly to the tone arm. This type of unit is used by most professionals. If you want some though be prepared to pay professional prices. This type of styli will set you back approximately $89 a pair (ORTOFON Concorde DJ).
Provided by The DJ Source