Whether your turntable is a cherished lifelong friend or a recent thrift store acquisition, you'll need to replace its stylus periodically. A worn stylus doesn't deliver the audio quality it should and over time it can begin to degrade your records. You might also opt to upgrade to a higher-quality stylus for improved sound. In either case, the physical replacement is a simple process once you've identified your stylus. Just be careful not to touch or bend the actual needle, which can cause damage.
First, identify the make and model of the existing cartridge or stylus if you can. The brand name is usually visible on a Shure stylus, and the cartridge often displays a model number. Audio-Technica styli can be identified by their signature triangular stylized "A," and the cartridge may display a model number. If you can identify the brand and model number of the cartridge or stylus, you can easily locate it in the printed or electronic catalog available at most retailers. Alternatively, you can perform an Internet search and take your pick of online vendors who carry the correct stylus. If the stylus and cartridge show no numbering or readily identifiable markings, you'll need to take a few extra steps.
More Complicated Identifications
First, remove the unmarked stylus carefully from its cartridge. They're designed to come off if you pull straight forward or straight down, depending on the model. Hold the tone arm steady with your other hand, or lock it into its mount, before you try to extract the stylus. Many Shure styli have a small handle on the front, providing a convenient grip. If there's no handle, grasp the stylus gently but firmly by its sides. Try sliding forward first, and if that doesn't work pull downwards. Once you've removed the stylus, identify it using the photos in a visual cross-reference. These can be found online, or at most retailers selling styli.
Replacing the Stylus
When you receive your replacement stylus, examine it first for any visible damage that might have occurred in shipping. Remove the old stylus from your cartridge, setting it aside carefully in case the new one is damaged or doesn't fit. Take the new cartridge from its packaging. Slide it horizontally or vertically into the cartridge, reversing the method you'd used to remove the old stylus. Again, take care not to touch the actual needle. Good turntables often have a counterweight at the back, which determines how heavily your stylus presses on the record's grooves. To set this, adjust the counterweight until your tone arm balances perfectly. Look at the stylus' packaging for the recommended weight in grams, then turn the counterweight that many notches. The stylus end of the tone arm will gently sink to the record's surface when properly balanced.
Replacing the Cartridge
At times the best option is to replace the entire cartridge, either because styli for the old one aren't readily available or because you wish to upgrade to a superior product. This isn't difficult either. The cartridge is connected to the head shell by four color-coded wires. Remove these from the pins at the back of your cartridge, using needle-nosed pliers. It will still be attached to your tone arm by a small screw on either side, usually with a nut at the bottom. Hold the nut in place with pliers while you extract the screw, then gently pull the cartridge away from the head shell. Screw the new cartridge to the head shell, and then attach the wires to the pins of your new cartridge. They'll be labeled so you know which wire belongs to which pin. Adjust the counterweight, if necessary, before testing your new cartridge and stylus on a record.