Dover, perhaps to add to what Intact wrote, or not, if you move the pivot forward so the tonearm is not underhung but becomes either overhung or even set to hit the center of the spindle (I guess we can call this "un-hung" or neutral hung), then you can have no null points at all (without headshell offset). Because at the null point, the tonearm from pivot to stylus tip can be thought of as one side of a right angle triangle, let’s call that side A. The distance from the stylus tip to the center of the spindle is then side B of a right angle triangle, and the distance from the pivot point to the center of the spindle is side C, or the hypotenuse of a right angle triangle. Pythagorean Theorem tells us that for a right angle triangle, C-squared = A-squared + B-squared. But in the overhang condition, side A is greater than side C. So tangency is impossible without headshell offset. The un-hung situation cannot work either, where A = C.
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Dear @intactaudio : "" The combo of properly set offset + overhang is the only way to get the 2 null points. ""
Well, the standard alignments we all know including Stevenson B the null points are output parameters calculated from only 2 other knowed parameters that are:
most inner groove radius ( mm. ) and most outer groove radius ( mm. ). and from here came the standards: IEC, DIN or JIS. Null points calculation it not depends of any other parameter, not even tonearm EL. Again, that is for the knowed kind of alignments.
R. |
Whaaaa??? you need to specify at least four parameters which typically are alignment type, inner groove diameter, outer groove And Pivot to spindle (P2S). The math then returns you two null points, effective length (EL) and offset angle. The overhang (OH) is then found by subtracting P2S from EL. The knowns and unknowns can be reworked based on the information available. Effective length can be substituted with a known overhang and the P2S returned. dave |
@rsf507 , I would guess that @retipper would think you would haven to be out of your mind to buy a Viv arm. He probably would not state that directly as he would not want to lose customers. Manufacturers tend to be politically correct for obvious reasons. Maybe he will chime in. |
@rsf507 Re: Roy Gregory's problems w VTF. I haven't had a problem with this as long as I return the armtube to it's resting postion, a magnet at the outside of the housing that meets a short rod on the underside of the armtube. By returning the armtube to this position during the weighing process, I can be assured that it's in the position that it will hold as it traverses the record. |
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