antiskate disc

Come to think of it, when the original AR XA was marketed (late 60s or early 70s), most of us were using very light weight, very low VTF MM or MI cartridges (e.g., Shure and ADC).  Low cartridge weight and low VTF make for a low skating force, compared to the modern era of high effective mass tonearms and low compliance cartridges that require higher VTF. So maybe that is why or how Vilchur could justify the absence of an AS device on his tonearm, which probably was really left out to reduce cost. Then there is my experience with the underhung Viv tonearm, which trades skating force (not compensated for but lower than for any overhung tonearm) for tracking angle error (higher than for any overhung tonearm), and does it quite nicely.

The AR turntable was not my favorite.  From 1970 to 1980 I worked in high end hifi stores through college and when I was not at sea (I was in the Navy) and was a TT setup specialist.  The AR turntable wore out a lot of cartridges unevenly and the records it tortured.  I cannot say it was only because the thing did not have antiskate because the arm also had a lot of friction.  I owned one that I bought in 1969 before I understood it's limitations, but traded it for a Dual 1219 a year later, which actually had an excellent arm.  Then a couple of years later I traded it for a Thorens TD-125 MKII with a Rabco SL8E arm which I fought with for about 2 years before getting smart and switching the arm for an SME.  I still like that 3009 and have one on my VPI HW-19.  Some things are just right you know.  And some things are not.

Yeah, the AR XA tonearm had many more flaws than merely the absence of AS. But Vilchur was an articulate and erudite defender of it.

Clearly the XA bearings were primitive in terms of machining and design, especially the cockamamie vertical needlepoints with the silicone oil damping contraption. Later models like the 77XB I have used a simpler one piece part. I run an AT-71 on it and it tracks at 2 gr just fine. One of my 4 working turntables. 

I agree with macg19. wppf, etc.  The most foolproof, most accurate way to resolve this issue is to invest in the new version of WAM Engineering’s WallySkater.  WallySkaters have been a trusted reference for me for years, with everything from a lowly Ortofon 2M Black to my new DS Audio optical. No other tool comes close.  Yes, there’s a learning curve (a lot shorter with the new model), but IMHO, it's the Gold Standard.  Period.

You might also want to review WAM guru J.R. Boisclair’s Youtube tutorials that discuss antiskating.  He makes a convincing argument, based in non-voodoo physics, that the blank-disk method produces incorrect results.  I’m generally a tough sell, but he sold me.

They also show that horizontal-bearing dynamic friction can contribute greatly to skating-force measurements, and that bearing quality has a great effect on skating forces.  The WallySkater, to its credit, measures & optimizes both.  This is especially important bc J.R. has empirically confirmed that one of the most significant sources of the worst types of audible distortion (as on sibilance), is not misalignment-related mistracking, not bad VTF settings, but  excessive bearing friction.  Again, these are not audiophile conspiracy theories or conclusory pronouncements by self-identified experts.  When J.R. makes an assertion, it’s based on high-precision (often microscopic) empirical measurements and a thorough vetting of a corroborating physical model. 

J.R., as most of you know, is an uncompromising, out-of-the-box thinker who has arguably advanced our understanding of cartridge/tonearm physics more than any other person in my lifetime.  And I’m not young. 

Hey, I have no financial interest in WAM, but I think that every vinyl fan owes it to themself to watch at least some of the WAM tutorials before attempting to align a cartridge or select a tonearm.  I have a degree in Physics and I gotta tell you, J.R.’s observations gave me a whole new level of understanding of the statics and dynamics of vinyl playback.