A record player stylus is the needle-shaped portion of a phonograph, or record player, that contacts the record and transmits the vibrations it receives from the grooves of the record. They are often called needles due to their shape. They are, however, very much different from other types of needles, such as those used for sewing or in medicine.
In order to produce the sounds recorded on a vinyl record, a record player stylus is needed. The stylus follows the grooves on the record, and transmits the vibrations imparted to it by the minute variations in the grooves of the record. The quality of the stylus will influence the fidelity of the sound reproduction, and a discerning ear can easily detect the difference between a high quality stylus and a poor quality or damaged one.
A high-quality record player stylus will exhibit three main qualities. It should resist wear, as it is the only part of the record player, other than the pad that holds the record, to come in contact with the record itself. It should faithfully and accurately follow the grooves on the record, reproducing the sound as it was recorded. Lastly, it should not damage the record, keeping to a minimum the wear it imparts to the record over repeated playings.
The materials used to make record player styluses have changed over the 120 or so years since the invention of the phonograph by Thomas Edison. The first record player stylus was made from steel and was intended to last only a short time before being replaced. Improvements gradually lengthened the life of styluses so that they would last for hundreds of uses. Cartridges to hold the stylus made changing the needles much easier and quicker than in early models.
Gradually phonograph manufacturers developed better and better materials for their styluses, using such materials as tungsten, copper, and even cactus needles. As technology developed, so did record player styluses. Man-made sapphire and then diamond became the preferred material for the highest quality styluses. Today, highly sophisticated grinding and shaping techniques are used to shape the diamond needles used in a record player stylus in order to provide the maximum frequency response, creating the most faithful sound reproduction possible on any record.