Feel Silly Asking This Question Alignment Parameters

On my arms it takes more than I expect to hit the numbers, and I typically back it off a touch.

@wrm57, @lewm The best way to see this is with a naked cantilever. The AS setting depends on the type of stylus used. For 9" arms the range is 9-11%. 9% for spherical, 10% for elliptical and 11% for line contact. I push it to 12% with really aggressive styluses like the Gyger S,  Replicant 100 and the Soundsmith MR. When lowered in the middle of a 33.3 RPM record the cantilever should remain perfectly straight. It's horizontal angulation should not change. It it leans outwards towards the right channel you have too little AS. If it leans inwards towards the left channel you have too much AS. The WallySkater settings get you right there without a trial and error nuisance. It also verifies that the bearings and AS device are functioning correctly. I have seen several arms with significant defects. I have also put the stylus down all along the radius of a record and the cantilever's angle does not change notably. When set at the beginning of the record you will see that the cantilever starts leaning towards the right channel just before the run out area proving that the skating force INCREASES towards the end of the record. Setting in the middle gives you a good average. The WallySkator should be adjusted so that the stylus floats over the center of the record. The Lyras,  Clearaudios and Van den Huls are great cartridges to see this. I use 20X loops and very bright lights to aid the process. Unfortunately, cartridges that extend over their cantilever make this difficult to see as will very low compliance cartridges. 

There’s a bit too much to address individually on this topic. The last thread that was loosely related to this this subject hit a few days after I put this blog post out.

TL;DR #1: There numerous excellent geometries to choose from. Dispense with your confirmation bias about Löfgren A/B, Stevenson, Uni-DIN, etc. And faithfully follow your favorite.

TL;DR #2: I strongly suspect the "controlled" experiments many have reported on this thread are heavily skewed by (1) not getting the zenith right and (2) varying it slightly with each setup - invalidating any comparison. Take a look at the distortion and tracking angle curves in the above post, when the zenith is off. I have not compared zenith errors across all alignments, but know this: zenith is the new azimuth, and it’s much trickier to get right than azimuth is. Aligning zenith using the cantilever is a much more flawed method than setting azimuth with a horizontal headshell and calling it "good".

I say this with humility. As @lewm commented above, I would hope that we all look back at our work product from 5 years ago and view it with disdain ... as far as how much progress we’ve made in our journey.

... Thom @ Galibier

Mijo, I don't know whether you agree with me or not, but what I wrote is that AS can be exactly equal in magnitude (and hopefully opposite in direction) to the skating force at only two points on the LP surface.  It seems to me this is true for any stylus shape, and length tonearm, etc.  Because AS is constant in magnitude and direction while the skating force describes a kind of eccentric parabola if you plot its magnitude with respect to the distance between the innermost and outermost grooves, and this is disregarding the vicissitudes of the skating force that are due to the program material.  A straight line (the graph for AS) will intersect the skating force parabola at two points, unless AS is incorrectly set lower than the skating force minimum or higher than the skating force maximum. And anyway, do you REALLY think there is much difference between 9, 10, 11, or 12% of the skating force?

@lewm You are right Lew. The question is what is the best average over the entire play area.  The amount of AS required increases with the size of the contact patch at any given VTF.  Studying cantilever angles is an extremely fastidious way of going about finding the right setting. Some would argue there is no right setting. Then I would argue why use AS at all. Most of us with 1/2 a brain are going to call that a bad idea. So since everyone with 1/2 a brain agrees that we should be using some form of AS, and we know that the skating force is variable, not a constant, how do you go about figuring the best average and a way to dial it in consistently with as little effort as possible. IMHO the WallySkater is the best way. If you want to look at cantilever angles to dial things in further, why not. I do this every time I use a new to me stylus profile. I have found that styluses like the Soundsmith MR, the replicant 100 and the Gyger S do best at 12% of VTF. Lyra's line contact and MSL's line contact take 11%. It will be interesting to see what the V15 MR with it's extremely high compliance and low VTF will take. I will have the Jico stylus tomorrow.