Is my anti-skating too strong.


I’m trying to adjust the alignment of the Ortofon Black Quintet cartridge on my Music Hall mmf 9.3 turntable.  When I put the stylus down on the alignment protractor, the tone arm pulls to the outer edge of the turntable.   Should I disable anti skating when doing alignment or is it set too strong?  Obviously haven’t done this too often.
Also, when listening to the anti skating track on The Ultimate Analogue Test LP, there is noticeable distortion at the end of the track which indicates too much or too little anti skating.  Any guidance here?
udog

Showing 9 responses by millercarbon

Zero anti-skate for alignment purposes.

Whenever you hear distortion, test track or otherwise, always remember the Left channel is on the Left (inside) side groove wall, and the Right channel is on the Right (outside) groove wall. 

Anti-skate pulls the arm to the outside. So too much anti-skate will pull the arm out too much, leaving too little tracking force on the inside, and so the left channel will distort. In the reverse, too little anti-skate gives too much force on the inside, and so the outside Right channel will distort.

Skating forces are generated by the angle of the cartridge being dragged through the groove. Therefore, the higher the volume, the bigger the groove amplitude, the greater the drag and therefore the greater the anti-skate needed to counter it. Notice then this changes constantly depending on the music. So if you use a test LP and set anti-skate high enough to track really high amplitude test tracks, do not be surprised if it is too much anti-skate for a lot of your music. You may or may not notice a problem. Usually people only notice problems at the extremes. Just something to keep in mind.

All of this stuff is childishly simple once you learn how to think it through. Where it gets hard is when a million audiophiles start telling you all kinds of stories and getting you trying things without ever explaining so you understand why. Once you understand why the questions evaporate, you know the answers without even asking.
OMG sorry but it has nothing to do with the angle of the cantilever. The skating force that pulls the arm towards the center is a result of not being tangential. It has nothing to do with the offset angle of the head shell, or the cartridge, or the cantilever, or the stylus, or any of that.

This is why linear trackers are also tangential tracking. A pivoted arm would have zero skating force IF AND ONLY IF it is tracking tangentially. But since the arm is pivoted this can happen only at one point.

Turntables and tone arms are actually childishly simple devices, literally as simple as a teeter-totter. You just have to stop and look at them closely to see what is going on. Please, please, PLEASE do that, and not get too caught up in other peoples stories about what is going on.
Geeze Louise! The lengths some will go just to try and get a dig in!  

Check this out- a line runs between two points. Just to help you out, we will call the points A, and B. Are you with me so far? Okay so we are gonna call the stylus Point A, and the Pivot we are gonna call Point B. Are you with me? Have I lost you? I bet I have, this is so hard. But it is only getting harder. Because sorry, but this is a story problem. You have the story. Now the question: Are A and B in a line? Of course they are. How can they not be? Anyone? Beuller? 

What you mean to say is the stylus is not in line with the arm tube. But this is completely different and utterly irrelevant. The arm tube can be straight, or curved, and the headshell also can be in line, or offset.  

These things make a difference, sure. BUT NOT TO SKATING!!! Please, please, PLEASE stop trying to confuse everyone by changing the subject! 


Saw the post from lewm from a while back. Yes lewm I do read what I write. The problem is not the writing. The problem is comprehending. Of which there is a lot of on this thread.    

Skating forces are generated just like I said, by the stylus overhanging past the tangent. When the stylus is tangent then the force of dragging through the groove is in line with the arm pivot and there is no skating force pulling towards the center.    

But all cartridges have over hang. That is why we call it overhang adjustment. Because of this overhang the stylus is always on the groove past the point of tangency. Because of this there is always a vector force towards the center. This is the skating force.   

Now lewm, this is where you want to pay extra special attention. The cartridge can be mounted on the arm pointing any direction. It can be angled in, or out, or at right angles- or backwards for all that matters. As long as the stylus is always in the same overhang position then there will always be the same skating force.     

Nothing to do with the cantilever. That is a whole different subject. This is where people screw other people up. Got to keep each thing straight. 

Now that everyone understands skating force comes from overhang, it should be obvious Fremer is right. (Or at any rate what Mike says Fremer says is right.) Because the skating force comes from overhang, then the greater the drag on the stylus the greater the skating force.  

This is why a blank record is no way to set anti-skate. A blank record has a lot less drag than a groove. A highly modulated groove has a lot more drag than a silent groove. Understand all this and it should be obvious there is no way to use VTF to calculate anti-skate, other than as a crude ballpark estimate. 

Please guys, don't make this harder than it has to be!
lewm- MC, Yes, if you can draw a straight line from stylus tip, through the cantilever, that intersects the pivot point, then you have zero skating force.

No. Wrong. That is not it. It's overhang. Last chance. Not gonna keep repeating. Explained perfectly clear already. Skating forces come from overhang. Period.

There's videos where Michael Fremer says this exact same thing: skating force is caused by overhang. No overhang, no skating. Nothing to do with the stylus, cantilever, or anything else. Michael Freaking Fremer! But then he tends to address an audience of people who want to listen and learn. 

Well I have tried my best lewm. You have the info. Everyone has the info. What you do with it is up to you. Choose wisely.
Justme, what I objected to in MC’s generalization was his saying “no overhang, no skating force”. I believe that is a direct quote from his post. The fact is that any pivoted tonearm, whether it overhangs the spindle or not will generate a skating force. 


NO NO NO WRONG WRONG WRONG! Actually worse than wrong, confused beyond recognition. Stop confusing everything!

Look lewm, you said spindle! The spindle has nothing to do with it! Skating forces are generated by the stylus not tracking tangentially.

Look, forget pivoted arms for a second. Think about tangential tracking arms.

Do you at least understand that a tangential tracking arm has no skating force to contend with? Because it is tangent. Perfectly perpendicular to the groove at the point of contact. Because when perfectly perpendicular the force is perfectly parallel to the arm and there is no skating force. Do you at least understand that much? 
Incredible the amount of confusion generated by such a simple thing. Given a teeter-totter you guys would figure out a way of explaining it that would go on for years and never get there.

Pivoted arms use a geometry that is cobbled together from a need to compromise several conflicting goals. Try not to confuse and conflate the different goals!

When the stylus is tangent to the groove (null point) the pulling force caused by the friction with be inline with the tonearm’s linear offset, thereby causing a rotational torque around the tonearm’s pivot.

This loopy logic results from confusing the STYLUS being tangent with the line from the stylus to the arm pivot being tangent.

We got a couple things going on. Seriously, keep them straight! 

We got a line that runs from the stylus to the pivot. When this line is tangential to the groove then groove drag is perfectly in line and there is no skating force. Period. Does not matter which way you rotate the cartridge, head shell, or any of that. Stylus to pivot perpendicular to groove, zero skating force.

This however is not gonna play music very well! So what we do, make the arm longer. The stylus now overhangs and is beyond tangent. The angle it is off is a vector and that vector force is pushing the arm towards the center. Head shell angle, offset, cartridge alignment DOES NOT MATTER! All that matters as far as skating force is concerned is the overhang. 

Say again, as far as skating force is concerned! Which, according to the title at the top of the page is the subject we are concerned with here. Skating.  

Skating forces have been explained absolutely perfectly by me about a dozen times now. Where people deliberately go confusing is adding in other stuff that we do that does matter but has nothing to do with skating!

The reason for some head shells being cocked off at an angle, or offset, or whatever, cartridge alignment, is all completely different. Now you want to talk about that, fine. But please understand we are no longer talking about skating. We are now talking about tracking angle.

Because the same overhang that introduces skating also puts the arm out of tangency, and this introduces tracking distortion. So we rotate the cartridge trying to get it back at an angle that is tangent.

This is where the cantilever is tangent to the groove. Please note, this is NOT the stylus-pivot being tangent. This is the stylus itself being tangent. We cannot see the stylus, so we use the cantilever as a proxy, and hope the manufacturer has done his job and the stylus is aligned.

Very, very, very important we keep all these thing straight. Each and every one. ALL the confusions above are people conflating, talking about similar but different and sometimes completely unrelated things as if they are all the same. They are not all the same. Get it straight or get it wrong.

I wouldn't mind so much, except playing records is really fun, easy, and sounds great. Until someone comes along with a simple question, and you guys make it seem impossible, and an endless struggle to boot! It is just not that hard. But no one can tell, not from reading stuff like this!

lewm-
MC, It's a matter of vector algebra, adding the various force vectors results in a net side force that can only pull the stylus toward the spindle
 
Finally. Took long enough. Thank you. 
@millercarbon could you post a link to any article that supports or further explains your skating force theory.

It's not a theory. It is physics. It is so obvious that Michael Fremer throws it out there as an off hand comment. I can explain it faster than I can find his 2 second sound bite in his 90 min video. So you go find it yourself if it is so important to you.

Here's the physics:

Draw a circle. Draw it nice and big, this will help for later. Put a dot in the center. That's your spindle. Now draw another point anywhere outside the circle. That's your tone arm pivot point. Now take a compass, or a stick, ruler- anything nice and straight- and set it up to go from the pivot point to anywhere, but let's stick with roughly an inch, beyond the spindle. This is your overhang.  

Now keeping the compass on the pivot point, swing it around across the platter until you get to the outside edge of the circle. Are you with me? Okay.  

Now go to the point where the compass is on the outer edge of the circle and very carefully draw a line parallel, that is tangential, to that point on the circle. Got it?  

Okay. That was all geometry. Now here comes the physics. The circle/platter is rotating. Rotational motion breaks down into vectors. The motion of each point on the circle breaks down into a vector that is pointed straight ahead, ie tangentially, and straight towards the center. Each and every point on a circle is the same distance from the center. Therefore the vector pointing towards the center is zero. The motion is entirely tangential.  

There are other forces involved but this right here explains why it is that if you spin a ball on a string and let go the string, the ball does not spiral off it goes in a straight line. So your straight line tangential to the circle is the only vector, and this means at this precise point where the stylus is the groove is moving in a perfectly straight line. A line that is infinitely short, to be sure, but straight nonetheless. (And this is why Newton invented the calculus, but never mind.)

So now look at your drawing. Notice anything? You did draw it I hope. No cheating! You asked me to explain, I'm explaining. Draw the damn thing!!!

What do you see? What I see is a straight line coming from the pivot point to the stylus, and another straight line tangential to the circle, and they cross at the point of tangency. They cross. They are not parallel. Are they? No. They are not. If they were parallel there would be no skating force. They are not. Which way is the tangent line headed? Slightly away from the spindle? No. Slightly towards the spindle? Yes. Draw an arrow on it. There is your skating force.  

What happens with overhang is the spinning platter exerts a large force pulling straight away from the pivot point, and also another smaller force pulling the stylus ever so slightly to the left towards the spindle. This is your skating force.

You can change the shape of the arm. You can change the offset. You can align the cartridge any old way you want. As long as there is overhang the inward vector will be there and that is your skating force.