Graham Phantom Anti-Skate. Is it effective at all?

John,

You quoted Stringreen's contention about why tonearms include A/S but also addressed your rebuttal to me, as though I had seconded that statement. I didn't and I don't. Please don't ask me to defend statements I haven't made.

I'm unaware that any tonearm designer (except Harry Weisfeld) has publically stated why their tonearms offer A/S. Like you, I'm prepared to believe they do so in an attempt to counter these proven (if largely unquantifiable) forces.


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If you complain about the effects of the outward force applied using antiskate, but to where does the inward force magically disappear when not using it? None of the anti skate advocates have addressed this, nor why the unequal forces mysteriously don't cause distortion.

The inward force doesn't magically disappear, obviously. However, it does not necessarily result in distortion. Here's why:

Skating forces put an inward bias on the stylus. The stylus wants to skate inward but is constrained by the inner groovewall. Of course the stylus may lose contact with the outer groovewall. THAT will cause R channel distortion. However, so long as steady contact is maintained with both groovewalls, no distortion will occur. If the stylus traces the grooves accurately, it will reproduce accurately (for its part).

The question becomes, how best to maintain constant stylus-groovewall contact. As I've repeatedly said, with MY cartridge on MY tonearm, this is best achieved by zero lateral force and very careful tuning of VTF (I routinely tweak by much less than .01g). As I've also repeatedly said, other rigs may and often do respond differently.

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I'm open minded. I'd be happy to use an A/S device that operated correctly. Unfortunately, the mechanics of a correctly operating A/S device, while theoretically possible to describe, are virtually impossible to achieve in practice.

Skating forces act on the stylus (NOT the tonearm). Therefore, the ideal A/S device would counteract those forces AT THE STYLUS. The notional perfect device would be a self-adjusting, elastic thread attached to the STYLUS and pulling outward. Aside from being practically impossible to build and operate, even this otherwise perfect solution would still be challenged by not knowing exactly how much outward pull is needed to counteract the varying amount of skating force encountered from one musical passage to the next. Still, if such a device existed or could exist, I'd give it a try.

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Unfortunately, every real A/S device acts on the TONEARM. This is the only practical way to build it but this incorrect implemention causes the distortions Stringreen and I dislike, because it applies the counteracting lateral force at the wrong place.

The LP is pulling inward on the stylus while the A/S device is pulling outward on the tonearm. Where are these counteracting forces mediated? In the only place that there's elasticity to prevent something breaking: the elastic suspension between the cantilever and the cartridge body.

As Stringreeen correctly stated, this external pressure causes artificial damping of the cantilever. This would not occur in our notional perfect A/S device, but as we've seen, that does not and probably cannot exist. With A/S applied at the tonearm, in MY system, the sonic degradation is instantly audible. Your system or ears may well respond differently, of course.

The LP is pulling inward on the stylus while the A/S device is pulling outward on the tonearm. Where are these counteracting forces mediated? In the only place that there's elasticity to prevent something breaking: the elastic suspension between the cantilever and the cartridge body.

Doug, you may very well be right about this assertion. It has a common-sense ring of truth. And I don't doubt that your rig sounds better (to you and others) without A/S; this vector-force narrative would seem to explain it in a scientific way. But I have to wonder about the actual physics of it. Now, I'm not a physicist (my PhD is in English, not Physics) but it seems logical to me that, with a rigid tonearm, the lateral force of the A/S device is transferred to the stylus, and the "mediation" of this force through the elasticity of the cartridge suspension would occur only if the A/S force is being met with a countervailing force at the stylus tip, in other words, the outside groove wall. Under these circumstances, of course, too much A/S force is being applied. Otherwise, the transmitted force merely relieves pressure on the elasticity of the cartridge suspension, pressure caused by too little A/S.

I'd love to have someone qualified in the physics of tonearm geometry and vector forces weigh in on this fascinating subject.

For precision, I should have said: "...and the *deleterious* 'mediation' of this force through the elasticity of the cartridge suspension would occur only if the A/S force is being met with a countervailing force at the stylus tip...."

Because unipivot arms are balanced on the point of a pin, if the arm is set up properly it will compensate for any nonlinearity elsewhere.

My vinyl experience over the years has not included LOMC's or other cartridges having relatively low compliance, such as I presume most of those participating in this discussion are using. FWIW, though, using MM's and MI's having relatively high compliance (primarily Grace F9-E variants, including non-Ruby, Ruby, and Soundsmith re-tipped Ruby versions), primarily on a Magnepan Unitrac unipivot arm, with VTF generally set in the upper part of the recommended range for the particular cartridge, I have over the years consistently found that:

1)Left or right deflection of the cantilever, as viewed from the front of the cartridge when playing a record, will closely match the corresponding angle (nominally straight ahead) that is assumed by the cantilever when the stylus is raised above the record if anti-skating is set to approximately 50 to 65% of the amount recommended for the particular tonearm at the particular VTF.

2)A setting can be found in that range which will result in imperceptible left or right cantilever deflection at ALL points on the record.

3)Modest deviations from that amount of anti-skating force (either higher or lower) will ALWAYS (IME, as described) produce clearly perceivable sideways deflection of the cantilever while playing a record, which will NOT vary perceptibly as a function of what part of the record is being played.

4)I have never tried an anti-skating setting approaching zero, because given the foregoing it would seem absurd to do so in these particular circumstances.

Hopefully that datapoint will be of some usefulness in the discussion. Best regards,
-- Al