Antiskate force , what is yours

[prudence633]

I have a Stanton 981 HZS NOS stylus with brush run 1.25 grams tracking + 1 gram. Same for antiskate. On a Thorens Td125 MK ll. TP-16 arm. Came that way new from the store where I bought it many years ago. Dave at VN put a new arm on mine about 7 years ago.

 

[Thomas_AA]

Antiskating force is just 10-15 % of VTF for a 9 inch arm so there are really no worries. At least if it is set in that range. Some set it wrong though, or some turntables have poor AS calibration, which can be seen on cartridges used with too high AS (bent cantilever and uneven wear).

 

[borchee]

Yes, but if you have zero overhang the entire record, you have a linear tracker.

The over-/zero-/underhang doesn't change while playing; at least with a classical radial arm it doesn't. A (not every one) linear tracker can be over-/underhang as well, making it non-tangential.

 

[Sleiven]

You h

Actually, the skating force should be zero if there’s no overhang. Most tonearms are designed with slight overhang, resulting in inward skating force. In fact, the skating force can be outward if you align to an underhang condition. I choose to minimize the effect of friction variables (blank vs groove, stylus profile, wet play vs dry play, modulation level, etc) by setting to zero overhang, making the skating force zero to first order, regardless of stylus friction.

Actually, the skating force should be zero if there’s no overhang. Most tonearms are designed with slight overhang, resulting in inward skating force. In fact, the skating force can be outward if you align to an underhang condition. I choose to minimize the effect of friction variables (blank vs groove, stylus profile, wet play vs dry play, modulation level, etc) by setting to zero overhang, making the skating force zero to first order, regardless of stylus friction.

I am afraid you have misunderstood how the details of the skating force works. Take a look at the references and their vector diagrams . No overhang does not mean no skating force for a pivoted arm.

 

[deacon1blues]

I am afraid you have misunderstood how the details of the skating force works. Take a look at the references and their vector diagrams . No overhang does not mean no skating force for a pivoted arm.

I’d post a counter demonstration video, but Audiokarma is refusing to recognize my video. I’m fighting a head cold- will try again when it clears up

 

[Thomas_AA]

The over-/zero-/underhang doesn't change while playing; at least with a classical radial arm it doesn't. A (not every one) linear tracker can be over-/underhang as well, making it non-tangential.

Sure I get you, but the vectors change - the resulting tracking arc is there with a radial arm hence there is skating force. Again pointing to the faulty statement that zero overhang does not cause skating force. It does. A linear tracking arm may be set with overhang as well, but then it is poorly designed arm or an incorrectly set up linear tracker.

 

[deacon1blues]

Sure I get you, but the vectors change - the resulting tracking arc is there with a radial arm hence there is skating force. Again pointing to the faulty statement that zero overhang does not cause skating force. It does. A linear tracking arm may be set with overhang as well, but then it is poorly designed arm or an incorrectly set up linear tracker.

That’s correct. A radial arm can be set up for zero overhang in the center between the lead-in and run-out regions. The skating force at this center point will be zero, independent of VTF. With a reasonable length arm, the skating force at lead-in and run-out will be very small, smaller than the antiskate calibration error associated with the usual overhung tonearm designs..

Demonstration with antiskate set to zero:

Untitled.m4v

drive.google.com

 

[Rx4Pain]

No idea.

My cartridge is set up at 1.4 g and the anti skate is set on an acrylic platter to run neutral at three different platter positions, inside...outside...middle.
I look for inward and outward movement and put it in the middle of those two observations.

Usually corresponds to 1.5 on the Anti-skate scale give or take...I try not to get too anal on the turntable setup these days.

Ken

 

[deacon1blues]

You h



I am afraid you have misunderstood how the details of the skating force works. Take a look at the references and their vector diagrams . No overhang does not mean no skating force for a pivoted arm.

Untitled.m4v

drive.google.com

The antiskate has been set to zero in this demonstration. Note the negligible skating force due to the elimination of stylus overhang

 

[deacon1blues]

No idea.

My cartridge is set up at 1.4 g and the anti skate is set on an acrylic platter to run neutral at three different platter positions, inside...outside...middle.
I look for inward and outward movement and put it in the middle of those two observations.

Usually corresponds to 1.5 on the Anti-skate scale give or take...I try not to get too anal on the turntable setup these days.

Ken

Agreed. I just find that being able to eliminate the need for antiskate is an easier way to go about it

 

[Thomas_AA]

That’s correct. A radial arm can be set up for zero overhang in the center between the lead-in and run-out regions. The skating force at this center point will be zero, independent of VTF. With a reasonable length arm, the skating force at lead-in and run-out will be very small, smaller than the antiskate calibration error associated with the usual overhung tonearm designs..

Demonstration with antiskate set to zero:

Untitled.m4v

drive.google.com

This skate-anti skate error is very small for a traditional setup up arm when anti-skate is set correctly. Between 10-15% of VTF is what is needed for a 9 inch arm. The blank space method and cue-up method sets mine to ≈13 % of VTF. Nothing to worry about.

 

[tourmax]

Mine is setup on a blank disc to neither move in nor out when dropped.

That number on the AS dial is, oddly enough, precisely the setting on the AS dial Dual recommends for my cart on each table. IE: if the VTF is set at 1g, the AS setting is "1".

Anyways, that's how I do it.

YMMV.

 

[borchee]

Sure I get you, but the vectors change - the resulting tracking arc is there with a radial arm hence there is skating force. Again pointing to the faulty statement that zero overhang does not cause skating force. It does. A linear tracking arm may be set with overhang as well, but then it is poorly designed arm or an incorrectly set up linear tracker.

I agree, of course. I wasn't trying to correct you, but to broaden the view, because "Yes, but if you have zero overhang the entire record, you have a linear tracker." can be interpreted in not just one way.

And yes, a linear tracker arm with a "hang" is faulty, though I can't imagine any company screwing the design up with a TP-mount. With 1/2"-mount it can only be due to the user:
- cartridge mounted incorrectly on a headshell that allows for movement of it
- cartridge with improper center-of-mounting-holes-to-stylus-tip distance mounted on a headshell with fixed mounting.

I haven't come across a claim that linear trackers with a "hang" sound better. Yet!

 

[Sleiven]

Again, overhang is not setting the skating force. It only affects the tracking angle error which is what is causing the VARIATION of the tracing force across the record. The skating force is F= u* sin (A +B) * VTF where A is the arms offset angle and B is the tracking angle error, where B depends on arm length and overhang and the position of the arm across the record . u is the friction coefficients , latest sources indicate a value about 0.3. The formulas are given in the standard texts/articles.

Since a typical offset angle A is 22 degrees and tracking error less than 2 degrees across the record , The variation in skating force can then be calculated.
Setting overhang to 0 does not eliminate the skating force , it just alters the variation in skating force across the record. A for a given arm there is ONLY one optimal overhang depending on your choice of alignment . ( pick your poison L or B or S)

Using sin(20)=0.342 and Sin(22)=0.375 and Sin(24)=0.407 we see that the variation of skating force is about +- 10% across the record

 

[Nat]

Having set up a couple of non P mount linear tables, I suspect quite a few of them are not properly aligned. Unless you have the jig that came with the table, and many don't (and they aren't usually interchangeable), it can be quite difficult to do, And not getting it right means that the stylus is constantly misaligned - users of pivoted arms can take some comfort in knowing that. even with some misalignment. probably there will be two points where there is zero error, but a misaligned linear is alway misaligned.
And aligning is difficult - to move the arm, or even to cue it, you usually have to have the power on, which means the platter is usually moving. You can unplug the machine, but getting the timing right can take some practice. I see people saying that it is easy - just place the stylus on the center of the spindle. Yeah right - most arms cannot go as far as the spindle, and even if they can (as in an independant arm), not all can tilt that high. And if you recognize that the arm when it lifts and lowers inscribes an arc, you will also recognize that putting the stylus on the center of the spindle will ensure that the stylus is a little bit underhung. Seems like a lot of work just to make sure it is slightly wrong.

 

[patfont]

In the Hi-Fi shop I worked at we set up each turntable and cartridge.
We used a test record and into the oscilloscope and you could pretty much get it spot on.
Very few manufacture set up directions will get it right.

Pat

 

[Thomas_AA]

In the Hi-Fi shop I worked at we set up each turntable and cartridge.
We used a test record and into the oscilloscope and you could pretty much get it spot on.
Very few manufacture set up directions will get it right.

Pat

What test record/track was used

 

[catBot]

Mine is 0 (zero), as the tonearm here is tangential.

 

[patfont]

What test record/track was used

Good question, let me see if I still have mine.

Pat

 

[Thorsten R.]

But the test record method, which I use myself, is not without trap. As the skating force depends to a great deal on the resistance of the needle in the groove the usage of the "equal distorsion on both channels" - method leads to the correct value at very high modulation. Which should be too high for "normal" modulation. That´s why I believe the best approach is to choose a value between this method and that found with the blank disk - method.