A new way of adjusting anti skate!

Took most of my first cuppa joe this morning to parse this thread.

 I seem to recall adjusting this visually after balancing my tonearm in neutral, and sort of compromising on too little vs. too much movement of the TA as I made AS adjustments at outer-mid-inner points of the platter. 
 

then adjusted VTF and as a final check, looked at the cantilever position to make sure it was centered- it was.  I used a Tracking Wizard disc for TA setup initially.

Now I could have done something like played a 1 kHz tone from my Ortofon setup disc, run the cartridge output through my oscilloscope and compared L-R values in real time.

Nah. Visual and auditory seem to work for me so far.

My dad was a tool and die maker, got into plastic injection molds in the 1960’s. Company he worked for got the contract for the very first Bic pens and butane lighters. He passed on a 1% stock ownership option he regretted to his dying day. A WW2 vet, he merely said he was a Zippo man and let it go at that. I used to stop by the shop to watch him work and he showed me once how he could judge 1/25,000 inch thickness change using a thumbnail. The human machine can be nearly as accurate as machine measurements- he used laser interferometry for projects for NASA with a millionth inch tolerance, “rule of thumb” being too broad an application for such refinement.

upshot here is the last comment I read was the last I think I need before I pour another cup and move onto some paperwork-

“@lewm

9,731 posts

12-28-2021 1:59pm

Use an amount that does not give you distortion in the R channel (too little) or in the L channel (too much) and does not result in a deviated cantilever after several hours of play.  And then, forgeddaboudit.”

Wise words. Thanks.

Mijostyn, There you go again! Velocity is NOT a factor in determining the friction force. Friction force is very simply equal to the net force vertical to the contact surfaces of two objects (VTF in this case) times the coefficient of friction, which is different for any two materials in contact. So pre-supposing an effect of velocity on the skating force is invalid, if the angle in the equation for skating force is equal to the headshell offset angle. If velocity was a factor, you would have to change AS significantly for 45 vs 33 rpm LPs. Not to mention that the outer groove velocity is so much greater than the inner groove velocity that "velocity" would dominate the problem of setting AS. In your last post, you say the angle IS the headshell offset angle, but then you go on to say, "The reference is to the arm’s pivot not the record". I am not sure what that means. Headshell offset angle is the angle by which the headshell is "bent" with respect to the arm tube, as I am sure you know. It’s a constant at all times. But tracking angle error (TAE) is constantly changing during the course of play. This aspect of TAE causes a constant shift in the direction of the friction force vector which alters the magnitude of the skating force. So I posited that the "angle" in your equation could be defined as TAE + headshell offset angle. At the null points, TAE is zero but headhell offset alone still causes some skating force.

In the above, I confusingly wrote, "So pre-supposing an effect of velocity on the skating force is invalid, if the angle in the equation for skating force is equal to the headshell offset angle." That’s wrong on the surface. I meant to emphasize that velocity is not a factor, regardless of angle. And as a separate matter, the equation quoted by Mijo is also invalid if it is dependent only upon headshell offset and not TAE.

@normb ,  listening for distortion and watching the cantilever displace as it hits the record are sort of arbitrary. To get a good cartridge to distort requires very high groove velocities that over estimate the AS force required. The cantilever displacement was useful in the days of high compliance cartridges but not with the ones we use today. They are too stiff. Frank Schroders advice to set it so the arm slowly drifts inwards when placed between grooves in the run out section is probably the best low tech way of setting it. The equation I mention above is very specific except there is no one value for the kinetic coefficient of friction. There is a range. Using the Wally Skater and my device are really very simple and you know exactly what you are doing with a very specific target which is reassuring. Then you just forgetaboutit.  I have also used my modified gauge to verify that the Schroder method does indeed come close and using the blank record method consistently over estimates the AS force. I did not study cantilever displacement because by     the time the cantilever starts deflecting with my cartridge the AS is way off.  

TL;DR after @millercarbon’s and @lewm’s first posts (both of them being excellent, and I agree with them).

Trigonometry aside, and one thing that is lost on most individuals is "what are you adjusting for?"

The obvious answer is distortion, but all too frequently (and very much like tracking force), being able to track the most challenging A-S track on your test record is not necessarily ideal.

Excess tracking force and anti-skate (even if within your cartridge manufacturer’s specs, as far as tracking force is concerned), will likely compromise the dynamic presentation.

That’s a big "no-no" in my book, and the more I do this stuff, the more my final tuning steps address dynamics.

Now, in no way does this mean that I like distortion (quite the contrary), but given the choice of very good distortion performance with outstanding dynamics, vs. outstanding distortion performance and mediocre dynamics, I’ll always choose the former.

You might say that in phrasing the above choice the way I did is a straw-man argument, but the fact is that dynamics fall off a cliff very quickly with either too much tracking force or too heavy a hand with anti-skate.

I make a big deal about this in the free setup report you can pull down from my website.

... Thom @ Galibier Design