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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
sunnyjim OP
927 posts
 

To Almarg, The 4th  paragraph of your response is what I have generally read in various audio magazine including the out of print Stereo Review  The  order of my turntables has been Garrand SL95B,  Thorens 160( actually borrowed from a friend while my Benjamin-Miracord TT sat in a service shop for three months)  Sonograph turntable,  VPI Junior,  Rega 3-24,  Project DC Carbon, and currently a refurbished Thorens TD-145  

To my best recollection, only the Garrand SL95B and possibly the B. Miracord  employed "hook, line and sinker" anti-skating device  For the record,  both  Thorens indicated above did not use this type of anti-skating. The Thorens anti-skating  is simple, but also seems like a toy. You crank a dial on the tonearm to match the tracking force. In addition, it has a scale of  elliptical and conical  stylus , and a scale should you play your LP after using a liquid cleaner. According to a Thorens tech  was the method used in Europe, (possibly only Thorens)

The Rega P3-24 despite its excellent tonearm also employed an anti -skating device that was set by moving to the prescribed setting represented by a series of notches which their inadequate manual illustrated There was a small dial to move to the prescribed notch. I hope Rega has no plans of getting into the drone missile business. It appeared to me a primitive and imprecise device, regardless of  what side of the anti-skating argument you are on.  I don't recall if it was called "magnetic" in the ads or manual

In the August 2016 issue of  Stereophile, there is a full sheet ad on page-46  for  Project's  "upgraded" RPM3  in "fire engine red"  The ad lists in bullet points its improved featrues including  "magnetic anti-skating mechanism"   which is carried forth on the RPM 5  and the RPM-9  tables; The (discontinued) Project 1bXpression clearly shows the fishline and sinker anti-skating, but not the new Project 2BXperience SE. The (discontinued) Music Hall 5.1 table has the device, and also the Music Hall "Ikura" table. 

It appears  that some TT manufacture employ a magnetic anti-skating mechanism to its higher end tables, but this is not necessarily  consistent as can be seen on the MH 5.1, and possibly their new MH 5.3 table.

 Marantz 15 S1  table, and Clearaudio Concept TT do not use the fishline etc etc.    Quite an audio conundrum!!!    Thanks , Jim    

atmasphere's avatar
atmasphere
12,168 posts
 
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.
So you're saying that despite being perfectly tangential, skating forces still exist? IOW that they are generated by the arm and not the geometry of the stylus in the groove?
ct0517's avatar
ct0517
2,041 posts
 
One way of demonstrating this is to raise the arm, stare at the cartridge from the front, wrap an elastic around your cartridge body (not the stylus/cantilever** ) and pull straight out toward you.

** Not responsible for any beheaded cartridges. 8^0

Hi Henry - hope you are enjoying your winter.
Its been terribly hot/humid here. Been staying at the lake up north (for me) pretty much full time. Sunnyjim thanks for letting me catch up on your thread.

"HOOK. LINE, AND SINKER" ANTI-SKATING"


funny...good one. :^)


I never expected such an impassioned discussion over the anti-skating used on many turntables.

Myself I have never met any audiophile that was not passionate. And vinyl guys (not really gals from my experience) are over the top.
I mean this in a good way. After all we could be into other things causing no good. We are not hurting anyone.




lewm
13,764 posts
 
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.

thom_at_galibier_design's avatar
thom_at_galibier_design
729 posts
 
TLDR (too long, didn't read - so some of this may have been covered) ...

In general (because especially with anti-skate, there are no hard and fast rules), the smallest bit of anti-skate has worked best for me ... definitely err on the side of too little (to retain dynamics) rather than too much.

With some unipivots, a touch of anti-skate can have a secondary positive effect of stabilizing the arm a bit.

Gravity vs. magnetism?  Both are constant forces, and you can engineer a system so either one works (progressively increases as you track toward the inner groove), or alternatively is sub-optimal.

Cheers,
Thom @ Galibier Design
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