A unipivot does have the freedom of movement to rock from side to side. Whether this wobble actually occurs when playing a record, and the degree to which such motion will adversely affect the sound, is the subject of much debate. But, the Vector arm is NOT a conventional unipivot. In addition to the pivot point at the top of the arm, there is a second point perpendicular to the main vertical pivot that stabilizes the arm. The Vector arm is weighted to lean in one direction (clockwise tilt if you look from the front of the arm toward the pivot). That tendency to lean toward the right is resisted by a horizontal pin that contacts a bearing around the axis of the main vertical post/pivot. By screwing that horizontal pivot in or out, that stabilizing pivot also allows for precise setting of azimuth.
This design means that this is NOT a unipivot--it has two pivots, and it is stabilized from any kind of rocking motion. As with any design, this involves some, at least theoretical, disadvantages, such as an increase in friction in the movement of the arm.
This design means that this is NOT a unipivot--it has two pivots, and it is stabilized from any kind of rocking motion. As with any design, this involves some, at least theoretical, disadvantages, such as an increase in friction in the movement of the arm.