The Rotary Headshell RS-3 by the Japanese company RS Laboratory has similar design objectives to the Korean-made Swing Headshell reviewed in this column a while back. They both sacrifice tracking accuracy to some extent to minimize the interference from side forces during playback, as well as mechanically decouple the cartridge from the tonearm. The main differences are the RS-3 does not employ springs, and given the cartridge is installed as instructed with the stylus aligned precisely with the rotation axis, the overhang distance does not change during play as in the Swing Headhsell's case. In lab tests compared to a conventional headshell, the RS-3 indeed successfully reduces the amount of anti skating required to cancel the side forces when using the same cartridge model. In measuring the cartridge-arm natural resonance, I find the RS-3 does not significantly alter the resonance behavior of the combo, unlike the Swing Headshell which breaks up the resonance frequency into two separate peaks. Given the above findings, one may conclude the RS-3 may inject less sonic character of its own.
