Feel Silly Asking This Question Alignment Parameters

bill_k, Can you direct me to Peter Ledermann’s quote as follows: "With all due respect you [referring to me, Lew] stated that "AS is constant in magnitude" which is not true. As Peter Ledermann confirms: "A properly designed anti-skating is non-linear, as it should of course increase A-S automatically as the cartridge approaches the inner grooves."

This stimulated me in several directions. First, it may have been flippant of me to say that AS is constant in magnitude across the LP surface; I should have thought about it in greater detail, but if you consider an old-fashioned string and weight AS device, what would change the magnitude of AS force as the tonearm swings in toward the platter is the angle of the pull of the string/weight on the arm wand, assuming that friction of the string on the guide is unchanging. That changing angle would indeed probably change the magnitude of AS, but such a change would be linear with a slope related to the changing angle of the pull force. That still does not mimic the ups and downs of the skating force. The AS force exerted by a magnetic device would also vary but also would not closely mimic the changes in skating force that occur in the course of playing an LP using a pivoted overhung tonearm. Finally, I wish I knew what tonearm Peter was thinking of when he wrote that passage. Finally, finally, is it indeed true that the max skating force occurs at the innermost grooves? Gotta think more about that one, but off the top of my head, the skating force would be related to the headshell offset angle at the innermost null point (a minimum) and then rise as the stylus approaches the runout grooves. Before the tonearm reaches the innermost null point, the skating force is created by headshell offset angle PLUS TAE. At the outer null point, it is again caused only by headshell offset. And at the outer grooves, again we have both TAE and offset. There is just no way to design an AS device to follow those variations, and this does not even take into account groove tortuosity as another ever changing source of a skating force.

@lewm - Just happened to catch your post, but for future posts directed to another user you should use @username so they'd be notified. I had to do some searching to find where I sourced that quote from Peter but got it. It's on the following page in the "There's More..." section. https://www.sound-smith.com/faq/how-do-i-adjust-anti-skating-my-cartridge He covers many of the important aspects of AS there.

FWIW, I wasn’t notified of your response.

The gist of my response to PL is that yes, AS devices might increase the AS force as the stylus approaches innermost grooves, but no, in general AS devices don’t follow the skating force in magnitude. Or AS does not successfully cancel the skating force, to put it another way. I don’t think PL would make that claim.

So I just watched the two videos that bill_k referenced, and I don't perceive any conflict between what Peter says and what I wrote, except for the fact I was technically incorrect to have written that the AS force is constant.  Upon further thought, I see now that, at least for the conventional string and weight type of AS devices, the force pulling the tonearm would increase as the tonearm approaches the label, because the angle between the string and the arm wand is approaching 90 degrees, at which point all of the mass of the weight (force, F) would be pulling on the arm wand in the desired direction.