What is more accurate: magnetic anti-skating, or barrel weight attached a fishline?


I have seen turntables from Project, Music Hall, and a few other brands that still incorporate a small barrel weight attached to short fishline string which is stretched across a hooking loop to set ANTI-SKATING. It seems to be an artifact from the 1960's and 1970's tonearm design. It is also easy to lose or break 

My question is how accurate is that "device" compared to magnetic anti-skating employed by many turntable manufacturers   Thank you

sunnyjim

Showing 5 responses by lewm

Ralph, I am saying that when the cantilever/stylus is tangent to the groove, the friction force generated by the stylus to groove resistance has a vector directed tangent to the groove, too.  But because the headshell is offset with respect to a straight line drawn from the cantilever to the pivot, there will still be a skating force due entirely to the headshell offset angle.  Interestingly, if you use an "underhung" tonearm (no off color pun intended) with zero headshell offset, then there can be only one null point on the surface of the LP with respect to tracking angle error, but at that one null point, skating force will also be zero, because the forces will line up with the pivot.

Nandric,
I think a magnetic set-up could provide for variation of the force with respect to the radius of the LP, depending upon how it is implemented. So, since there are many tonearms that use magnetic methods, why is the Sony so much better?

To the OP, Since the skating force is varying constantly along the surface of the LP, is a moving target that you can never hit with confidence, there is no point in getting worked up over the exactitude of the anti-skate force.

Salectric, I have a Triplanar, and I have listened to it with no AS.  In my system, I hear a pronounced and obvious distortion in the R channel especially. This is cured by re-application of a very small amount of AS. From this I concluded that the Triplanar, or my Triplanar, sounds best with a very small amount of AS.  I know that Doug Deacon and some others also expounded upon the evils of the Triplanar AS device, that it introduced some spurious resonances, but I don't hear that problem, either, so long as all the attaching screws are tight as possible.
Dear Ralph (Atma-sphere), I beg to differ slightly with your analysis.  For a typical pivoted tonearm that is mounted such that the stylus overhangs the spindle and the headshell has an offset angle, there will always be some skating force, even at the two null points on the surface of the LP, because at the null points, the headshell offset angle per se will still be a cause of some skating force.  Although the cantilever/stylus is, at those two points, tangent to the groove, the tonearm itself is not, due to the headshell offset.
Dear Sunnyjim,  Don't let this rambling discussion defer you from enjoying the wonders of music on LPs.  Hang on to the first principles, with which everyone agrees: (1) Skating force varies due to predictable and unpredictable factors across the surface of the LP, and there is to this day no sure Anti-skate mechanism that can sense variation in Skating force and automatically adjust accordingly.  That's the bad news.  (2) The good news is that a very tiny amount, for many, the least amount of AS, is "good enough" to eliminate  or dramatically reduce both audible distortions and wear on LPs and styli that result from the skating force, without any need to worry about variations in the skating force.  And finally, if this message still leaves you feeling anxious, there's always the linear tracking tonearm option.  No matter how you slice it, LPs rule.

Andrei, Here is how I think of it: A conventional pivoted tonearm is always set up such that the stylus tip overhangs the spindle.  Now think of the relationship between the tonearm, the radius of the LP (from stylus to spindle) and the pivot to spindle distance, as 3 sides of a triangle.  In order for the stylus/cantilever to be tangent to the LP groove, there must be a right-angle triangle formed such that the tonearm and the LP radius are sides A and B of the triangle that must meet at 90 degrees, per the Pythagorean theorem.  In such a triangle, the pivot to spindle distance is side C, the "hypotenuse".  Pythagorean theorem says that the length relationships of sides A, B, and C in such a triangle must be such that C-squared = A-squared + B-squared.  But, because the pivot to stylus distance is always greater than the pivot to spindle distance, when you posit overhang, this condition can never be met.  Thus, for a conventional pivoted tonearm, the stylus/cantilever can NEVER achieve tangency to the groove.  Headshell offset is a band-aid that permits tangency at two points along the arc traced by the stylus, but as noted above, headshell offset per se creates a geometry whereby there is still some skating force even at the 2 points of tangency.