antiskate disc

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.

Those videos are HERE but you will need to scroll down most of the page to get to the section in skating force. Each video is 5 minutes or less. 

Many thanks junebug.  I respect the knowledge of the folks at Wally Tools but was not aware of this recent series of videos.  It seems I've carried lots of incorrect information forward in my decades in this hobby. :^(