Zero Antiskate vs Stylus Wear


This article, based on a long term study, was “plagiarised” from another Forum. It’s quite an old article so apologies to “older heads” for whom this may be old news.
It comes from an era when light VTF = good, but was not necessarily true, however the basic principle of long term wear looks sound.
Styli were tested to destruction over their full lifecycle.

http://www.audiomods.co.uk/papers/kogen_skatingforce.PDF

Viewers may have to cut & paste but in the event of difficulty with the link I will give a brief summary :

Of 14 cartridge samples tested without bias, 9 of them suffered excessive wear on the inner groove. One was neutral and the remaining 4 were “outer wall”.
When bias compensation was applied to a group of 6 samples, the wear pattern that resulted was symmetrical.

Given the strong and logical argument that skating damages styli asymmetrically – and gives a skewed reading of the LP over time, the “deviations” are a concern i.e. why 4 of them behaved oppositely.
Poor bearings? Arm cable too stiff? Wrong geometry?

IMO most turntable enthusiasts considered it self evident that unilateral force would cause this type of wear pattern so we didn’t need to be told but documented study, even one as old as this, is always interesting.
The photograph of the spherical stylus is poorly resolved on this copy but it makes the point quite graphically.

Based on long term experience that the simplest things can affect the sound of a turntable, I cannot deny that the idea of “de-stressing” the cantilever by removing a poorly directed/located AS force IS attractive and may produce a degree of audible benefit…at first...(?!?!?!!!)
The doubter in me always asks the question : can a mechanical assembly successfully zero out all mechanical influence and give a pure result? (If true zero AS is the goal even arm damping might be prohibited?)

The principle of using excessive VTF (up to 50% more) to achieve the same “trackability”, without bias, it was suggested, merely accelerates the unilateral wear & tear with (presumably) commensurate damage to the LP(?)
The proposed compensation of up to ”50% extra VTF” sounded a bit excessive to me.
(I’d balk at applying more than 0.1g over maximum.)

Old as it is, I found this study mildly unsettling.
Comments and opinions are invited from both Zero-antiskate adherents and those who always use AS.
moonglum
Dear Raul,
Thank you for your kind remarks.
I agree that based on long term studies like this there is a fundamental cause-and-effect which cannot be ignored and unilateral stylus wear is not an option.

I think for this analysis they must have been using short-life styli (perhaps of the order of 400-500 hrs?) as opposed to todays 1200 hr MC tips?
To quote Len Gregory, “…the stylus burns more than it wears. Diamonds, unlike the song, do not last forever….”.
(Len has always been of the firm belief that 1200 hrs is the point where we should be considering a re-tip or replacement - significantly, "regardless of diamond quality...".)
Of course, coming from a professional re-tipping company I would expect such a strict definition of cartridge life :)

Granted, careful use and the judicious application of anti-skate could prolong that life but with, e.g. £5K carts, I wouldn’t be leaving anything to chance.
In the case of higher quality and more finely finished diamonds like the Allaerts it has been said that Jan Allaerts inspected diamonds 17 yrs old or higher and affirmed very little wear. In such an event my attention would turn to the records :)

I recall even in the decade that followed that report, the industry thought they were minimising record wear by tracking at 0.5g when in fact they were exacerbating it.
Sometimes the best intentions can be misguided.
Best regards,
Dear Actus,
Many thanks for kick-starting the thread. I had indeed given up on it a while back :^)

Yes, the VPIs are among those odd cases where the cord is temptingly placed for manipulation.
I suppose to verify that there was no interference from it you would have to do the Balanced free-arm friction test to see if it slows or accelerates at that "twist" setting?
Not sure how easy that is to perform with a unipivot design such as the VPI.

Since you're happy with the sound and the tracking, there may be no need to question or test it. :^)
Best....
Moonglum,
You're welcome! And just to make it clear, I do not question whether skating forces are of concern or to be ignored. I'm certainly not going to argue against the laws of physics. I merely noted that certain designs, such as VPI, might be handling the issue in their own way, whatever it might be, a strategically positioned wire or twisted wire. If that is the case, the tests are of limited value if done with different designs. I'd still very much like to examine my stylus at some point to determine any wear due to the skating forces, but right now I'm just going to enjoy the music!
Dear Moonglum: There is no doubt that we have to take in deep care on the right TT/tonearm/cartridge set up mainly recovery all the grooves recorded information and to degraded the audio signal the less.

Sometimes we fail on that " perfect " set up and if not we the analog medium is in charge to, due to its multiple imperfections, make it fails.

We can have a perfect set up but the off center LP has to much to " say " and the non-flat LPs full of waves makes that our " perfect " set up goes down changing all the time the VTF/VTA/overhang during playback and we can't do almost nothing to stop it.

There are so many set up parameters that always affect the cartridge traking/ride that in some way we are at " random " for what the analog medium " decide " it self.

The analog medium in theory could be exact like mathematics but on playback we experienced many times that that analog set up parameters theory is not acomplished. Imperfection is the name of the game.

Anyway, I always try to be as accurate as the medium permit me.

Regards and enjoy the music,
R.
Raul, your point is well taken. That is what makes vinyl playback so interesting. Perfection gets boring after a while. Something so special or romantic about the glow of the preamp tubes, the spinning platter and those golden tones- with a little background crackle :)