OK so a few weeks ago we asked some questions about how records work. This week we will look into the different types of needles.

An elliptical stylus

(aka bi-radial) is a record “needle” that is shaped like a sharp-edged knife. The diamond tip of the stylus is cut so that it’s elongated vertically. As a result, the stylus exerts less pressure per square inch on the vinyl — resulting in less record wear relative to a spherical stylus. In addition, because of its narrower front to back facing shape, the diamond tipped stylus is better suited to recover smaller high-frequency groove modulations. In other words, an elliptical stylus digs deeper into the vinyl groove, which improves higher frequency playback

spherical stylus

(aka conical) is a record “needle” that is shaped spherically — resembling a ball point pen. The diamond tip of the stylus is cut so that it’s symmetrical and rather round/circular in appearance. Because the contact area of the stylus is restricted to two very small points, the downward pressure or tracking force tends to increase record wear (see Figure 2). In addition, the relatively reduced contact area during playback results in a lower level of fidelity.Because a spherical stylus is easier to manufacture, it’s less expensive than an elliptical stylus.For scratching and back-cueing purposes, the spherical stylus is recommended. This is because — during scratching — the spherical stylus wears your record less than an elliptical stylus. Ironically, the same two small contact points that wears out your record during standard play (on a spherical stylus) is also the reason that your records wear down less during scratching (i.e., there’s less contact area being destroyed).

This article was written by Bob Wegner Pleases visit Disc Jockey 101 for the full brake down.

PDR