Downunder, I don't think we're really "debating" the 3 curves so much as we are talking about what curve is optimal for what tonearms and why. I recently got very interested in tonearms that have zero headshell offset angle and are designed to be mounted with "underhang", which is to say that the stylus tip does not overhang the spindle; instead it is set short of the spindle such that the tip is on the playing surface when the tonearm is pointed at the spindle. With such tonearms, of which there are only two I think, tangency to the groove is achieved at only one point on the surface of the LP, not two, and the most extreme tracking angle error can reach or approach as much as 10 degrees, at the most inner and outer grooves. (But it's more typically 5 to 8 degrees at worst.) BUT, on the other hand, there is zero skating force at that one null point.
What to do with this information? I have long owned an RS Labs RS-A1 tonearm, which is one of the two commercially available arms that use underhung mounting, that I know about. I always wondered why it sounded so good, despite its other rather gimmicky features. Then more recently, the Viv Rigid Float tonearm came on the market, which also uses underhang. The Viv company likes to talk about their floating bearing, of which I am a bit skeptical, but the arm gets great reviews and is revered in Japan and Europe. I think the reason that the Viv and the RS Labs may punch "above their weight" may be that the skating force produced by headshell offset is more noxious than the skating force that arises due to lack of tangency before and after the null point(s) for any pivoted tonearm. And by extension this suggests that our obsession with minimizing degrees of tracking angle error via headshell offset is possibly unwise.
Does anyone own a Schroeder LT? I rather like that one.
