John,
My point #4 was intended as a response to PL's (reported) use of a blank disk to adjust A/S. As no reason was cited in support of this (supposed) preference, invoking PL's name in support of it is purely an appeal to authority.
However, the second and third paragraphs of #4 unnecessarily muddied the waters and do suggest the error you noted. Please consider them withdrawn, and thanks for keeping me honest!
Doug |
I read PL's short treatise on AS, and it was unclear to me just what part of the LP he wants his disciples to use for setting AS. If you read his text carefully, he seems to be talking about the very short in duration end of play area, just before the cartridge swings toward the spindle. At least that's the way I read it. I probably need to read it again. If he's really just talking about a blank LP, then I am a bit troubled, as I think it makes sense to set AS based on how the stylus behaves in a groove. After all, groove friction is the genesis of the skating force in the first place. I nowadays take the numb nuts approach of just setting every tonearm at its most minimal amount of AS. If the LPs sound well balanced with that setting, I leave bad enough alone. I do also know that in my hands, my Triplanar sounded bad in the R channel when I tried "no AS"; I had to invoke at least some AS to get rid of obvious distortion in the R channel. This I know is contrary to Doug's experience with the Triplanar, but there it is. Maybe the stylus shape is responsible for the difference in the way Doug and I hear the Triplanar vis a vis AS. Or maybe cartridge compliance plays a role too. What's very important to keep in mind is that there IS no one correct AS setting, because the skating force is very inconstant, as someone else pointed out above. |
03-09-15: Adeep42
To all posters: Thanks for all the very interesting responses. Think I'll stick with HW and the no AS crowd. At least for the time being. I am looking for the Telarc Omnidisc and might re-evaluate then. Adeep, I note that you are using a moving magnet cartridge, while most of those who have been participating in this discussion are using LOMC's which presumably have significantly lower compliance. Given that in particular, I would suggest that if you have not already done so you make a point of looking at your cartridge from the front while the stylus is in the groove of a ROTATING record, and determining if the cantilever is deflecting perceptibly to the left or the right, relative to its position (nominally straight ahead) when it is lifted off of the record. Quoting from myself in this thread:My vinyl experience over the years has not included LOMC's or other cartridges having relatively low compliance, such as I presume most of those participating in this discussion are using. FWIW, though, using MM's and MI's having relatively high compliance (primarily Grace F9-E variants, including non-Ruby, Ruby, and Soundsmith re-tipped Ruby versions), primarily on a Magnepan Unitrac unipivot arm, with VTF generally set in the upper part of the recommended range for the particular cartridge, I have over the years consistently found that:
1)Left or right deflection of the cantilever, as viewed from the front of the cartridge when playing a record, will closely match the corresponding angle (nominally straight ahead) that is assumed by the cantilever when the stylus is raised above the record if anti-skating is set to approximately 50 to 65% of the amount recommended for the particular tonearm at the particular VTF.
2)A setting can be found in that range which will result in imperceptible left or right cantilever deflection at ALL points on the record.
3)Modest deviations from that amount of anti-skating force (either higher or lower) will ALWAYS (IME, as described) produce clearly perceivable sideways deflection of the cantilever while playing a record, which will NOT vary perceptibly as a function of what part of the record is being played.
4)I have never tried an anti-skating setting approaching zero, because given the foregoing it would seem absurd to do so in these particular circumstances. If you do not see significant sideways deflection, I suspect that your tonearm is applying significant anti-skating force even if none is intentionally being introduced. And if you do see significant deflection, my opinion is as stated in item 4 of the quote. In part because it seems pretty much inconceivable to me that the result would not be significant misalignment within the cartridge of the moving magnet relative to the coils, and in part because of the obvious issues involving the stylus-to-groove interface. Regards, -- Al |
I'm with Al. Plus, "listen" for distortion that is worse in one channel vs the other. I sometimes get this wrong, but R channel distortion indicates maybe too little AS. L channel distortion the opposite. In my experience, listening is an even more sensitive test than looking. Nowadays I am using high compliance cartridges, even a high-ish compliance LOMC (Ortofon MC2000). There is no perceptible cantilever deflection; nor do I hear L vs R distortions, using my no-brainer formula of "the lowest amount of AS that the tonearm provides for". Doug et al took the low limit down lower with the TP tonearm by substituting its AS weight with a few rubber grommets, at one point in this odyssey. I follow this policy also with the L07J tonearm on my Kenwood L07D, a Reed 2A, and the Dynavector DV505 tonearm. |
Thanks, Lew. FWIW, the procedure I use is:
1)I increase anti-skating until deflection to the left (toward the center of the record) becomes just barely perceptible. This is done with the stylus positioned approximately in the middle of the rotating record. I note the setting. In the case of my arm, the "setting" is the number of tiny metal pellets that are placed in a bucket.
2)I decrease anti-skating until deflection to the right becomes just barely perceptible, with the stylus positioned at approximately the same location on the record. I note the setting.
3)I set anti-skating to the mid-point between those two values.
4)I verify that no perceivable deflection occurs at other points on the record.
5)I declare victory :-)
As a rough ballpark, I have found that raising or lowering the resulting number of pellets by something like 15% will result in easily perceivable deflection, symmetrically in the two directions.
Best regards,
-- Al
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