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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

Showing 3 responses by moonglum

moonglum OP
619 posts
 
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,
moonglum OP
619 posts
 
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 OP
619 posts
 
Dear Raul,
I cannot agree more.
Like you say, perfection can only ever be a theoretical one. Adjusting factors e.g. on a per record basis would be soul destroying because one factor offsets others – which in turn would require correction. Such levels of technicality would quench the spirit and defeat the very purpose of listening to music.
It’s eminently more sensible to spend many days and many records advancing the setup to a happy medium then simply enjoying it. Perfectionism is only useful insofar as achieving the working ideal for one’s own turntable/s whilst in full realisation that temperature, humidity, record warps, manufacturing errors, stylus cleanliness, record cleanliness, etc are the Devil’s way of making sure it doesn’t always run smoothly.

It’s true, we can change our ambient temp or VTA or VTF seasonally to compensate for Summer-Winter changes, depending on which is easier, and we may clean our styli at different intervals, and if we have easy VTA adjustable arms we can alter the level of the arm from 120g -180g as easily as throwing a switch - thereby keeping that idealised relationship unaltered but when it comes right down to it, it’s all about maintaining a reasonable equilibrium.

Regarding your comments about record warps, I do find it interesting that if we introduce a 120g to 180g VTA offset we can clearly hear it and quantify it, yet our ears can be extraordinarily forgiving when it comes to warped LPs (which affects all LPs to at least some degree). Perhaps the ear/brain interface actually compares average rather than instantaneous values? :^)

Speaking of mis-drilling : one of the most obvious examples of wrongly produced vinyl is the HFN/RR test disc. I’ve owned a couple of samples of this and the centre was always drilled 1 or 2mm off centre.
This would result in a wavering effect when using it to adjust bias, with associated intermittent cyclic mistracking on the more severe tracks.
(Personally, I only use music to adjust bias but if one must use an HFN/RR I would advise only to focus on the fadeout of the 12db tone. With some carts of varied trackability and in various states of wear, I’ve heard the tone pulling to one side as the signal level falls to zero instead of remaining centred…although don’t be surprised if your cart shows no difference at your ”ideal” setting.)
Best regards…
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