Although the record player stylus’ job is to faithfully trace the record groove, this is made more difficult because it is not the same size or shape as the cutting stylus which originally made the groove in the first place. Partly, this is so that the playing stylus doesn’t modify the groove in any way itself, however the cutting head is similar to the replay stylus; it is held on a cantilever, or torque tube, so that the pivot point of vertical modulation is held at an effective angle (after taking into account the effects of lacquer spring back) of 20 degrees +/- 5 degrees with the surface of the master disc. It follows then, that if the replay stylus is likewise held on a cantilever at a VTA (vertical tracking angle) of 20 degrees, then vertical tracking error will be minimised, if not eliminated. In practice, due to the phase difference effect of stereo record grooves and the masking effect that this has on centrally placed instruments, a VTA error of up to 10 degrees can be tolerated in the vinyl replay medium. Of course, VTA does not affect mono records at all, since there is no vertical modulation of the stylus.

The cutting head sides themselves are nominally set at 90 degrees to the surface of the record, but to reduce stutter and “snow plough” effects when cutting into the nitrocellulose lacquer, this can be modified by 2 degrees towards the rear of the cutting head - but again, the spring back effect allows the resultant groove to return to an orthogonal state. It is important then, when using a stylus with a greatly elongated playing surface, such as Shibata or line contact type, that the stylus rake angle (SRA) renders the stylus playing edges at exactly 90 degrees to the record surface in order to retrieve the maximum amount of treble, and lowest distortion from the groove.

A properly designed cartridge will be built such that at the correct playing weight, and when properly aligned in a parallel arm tube, the correct VTA and SRA are automatically achieved. Even so, these two parameters must be a very long way out spec indeed for their effects to become readily audible.