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


I've had my Phantom Supreme over a year now, and for the most part it's been a pleasure. Beautiful build & sound; awesome VTA and azimuth adjustments. My main hangup had been the headshell; getting a Koetsu to sit flat on the 10" wand seemed impossible because the correct overhang pushed it all the way to the back, behind the main headshell points of contact. Finally I just used 2 plastic washers as shims to get a nice flat mount.

Now my main concern is the anti-skate. I'm not sure if all Phantoms are this way or if it's an issue with my unit. I can't seem to get an effective amount of anti-skate. My preferred method for adjusting anti-skate is to drop the needle in some dead-wax before the label (NOT into a lead-out groove) and adjust so that the stylus creeps *slowly* inwards. With my Graham, I cannot achieve that...it always moves quickly inwards no matter how far out I set the weight. Even physically pushing down on the weight doesn't seem to have much effect in swinging the arm. To me, this seems like the mechanism is not effective, as if I'm running without any compensation. This is very unlike my experiences with a Fidelity Research FR64fx (weight and fishing line) and Clearaudio Magnify (magnetic) -- both have a very noticeably effective anti-skate mechanism, which I can easily dial-in as described above. In fact I just setup a Magnify...it was great!

On my Graham, the pulley & rope system seems to be correctly in place. But without a 2nd until to examine, I can't determine whether this is normal. Could other owners/users of Graham please comment on their experiences with its anti-skate? The situation is OK for now -- I burn hours on my good cartridges very slowly and sparingly -- but I'd rather not have my nice cartridge seeing asymmetric wear over the long-run.

-- Mike
128x128mulveling
John ...even your last sentence is wrong. I suspect that there is such a thing as skating force....but it is a very slight, illusive and constant changing force. It is impossible to correct for it and most times it is overcompensated. Why do you say that there is distortion on one channel without A/S ?? If the vtf is adjusted properly, the stylus stays in the groove with no mistracking. The bottom line is that MY arm/cartridge sounds better with no A/S, therefore that is the better way. I tried it (a few times) with A/S, but the sound is always better without it.
As far as impact, I'm looking for deflection after the record groove is being
traced. You need to look at it before, during and after to see if it's consistent
with how it looked before dropping on the LP. It takes concentration. Even
so, I'm not too concerned about it...little is better than too much.
...and there is only one out there who used his brain to develop something useful, The Axiom Arm from Acoustical Systems. It has an independent leveling. A nice detail which will never get the respect it deserves :-)

Actually the Schroder LT had that feature before the Axiom came out. It is a very good idea.
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.


***

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.

***

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.

***

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.