Anti-Skating (out of spec?)

Discussion in 'Audio Hardware' started by LitHum05, Feb 11, 2019 at 1:17 PM.

  1. LitHum05

    LitHum05 El Disco es Cultura Thread Starter

    I've seen a few online tutorials on setting anti-skate using smooth record sides and/or compact discs. I'm wondering if my vintage Denon DP-1100 vintage turntable isn't so far out of spec that I cannot get the anti-skating to pull outwards. I can definitely get the arm to race to the spindle, but not the other way around. The best I can do (using a cd) is to get zero movement, but this requires a full blast of "3" on my anti-skate. Is this, then, my ideal setting? Or am I doing something wrong? I've been using the recommended 1.8 to match the 1.8 VTF on my Denon cartridge. I did at one point use a weight to verify that 1.8 was 1.8 as marked. It turned out that the setting was .5 grams off. So I fixed that. I wonder if the anti-skate has drifted even further. Help!! :yikes:
     
  2. JohnO

    JohnO Forum Resident

    Location:
    Washington, DC
    I have found that the antiskate dial indications can be way off. For one good turntable, with a 2g tracking force, the best setting on the antiskate dial, testing on the center playing area of a Laserdisc, is 1g (or really, "1"). Other turntables are about right on the dial or setting.

    Don't use just a CD to test, its diameter is too small and not what you are playing with a 12" LP. Get any Laserdisc at a thrift shop or a vinyl LP with a blank side and test in the center playing area equivalent to an LP.

    (I don't want to start an antiskate setting war. For those of us without $10k test equipment, the Laserdisc/blank disc test gets pretty close and closer than the dials.)
     
    LitHum05 likes this.
  3. allied333

    allied333 TUBE AMPLIFIER REBUILDER - inquire

    Location:
    MI
    I guess zero movement is better than racing to spindle. I set my anti-skate to moving slowly towards the spindle.
     
  4. LitHum05

    LitHum05 El Disco es Cultura Thread Starter

    I'm trying a laser disc next. Will report back.
     
  5. patient_ot

    patient_ot Forum Resident

    Location:
    USA
    If your anti-skate is the spring type that uses a dial, then yes, the springs can become stretched over time. There are a lot of different ways to set anti-skate but the method I usually suggest looking into is the one Peter Lederman talks about. You can search YouTube for a video. The problem with test records and laser discs is that you risk being over-corrected for anti-skate.
     
  6. LitHum05

    LitHum05 El Disco es Cultura Thread Starter

    The video about stylus shapes? What keywords should I use? Thanks.
     
  7. Davey

    Davey very clever with maracas

    Location:
    SF Bay Area, USA
    The best test record for anti-skate is the excellent Melanie De Biasio Blackened Cities EP from a couple years ago, it's a 24-minute one-sided record, so blank on second side. Great music, big favorite of mine (her No Deal record is excellent too, great sound quality as well, but it's got squiggles on both sides :)).

    Anyway, any blank record will do, the usual course of action is just set the anti-skating so you get a slow drift toward the center on a blank record, that gets you in the ballpark, you generally don't want to set it so high that it is stationary, though some test records advised that in the past. Laser discs and CDs are polycarbonate, not vinyl, so different results. Still, the best method is really to view what happens to the cantilever when you lower it onto a spinning record with music grooves. You shouldn't see it deflect one way or the other when anti-skate is set in the correct region. But this test also depends on the cartridge compliancy, with some of the modern low compliance cartridges you likely won't see a deflection.
     
  8. LitHum05

    LitHum05 El Disco es Cultura Thread Starter

    I keep seeing this advice everywhere. I must be blind. I can't see any bending on the cantilever regardless of where anti-skating is set.
     
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  9. LitHum05

    LitHum05 El Disco es Cultura Thread Starter

    Yes, it's a dial.
     
  10. LitHum05

    LitHum05 El Disco es Cultura Thread Starter

    Nevermind. I found the videos.
     
    patient_ot likes this.
  11. Davey

    Davey very clever with maracas

    Location:
    SF Bay Area, USA
    OK, like I said, it doesn't work with low compliance cartridges, though if using the Denon DL-110, that is probably mid-compliance, not sure, I haven't used it, but may not show. Many test records have tracks recorded at various peak amplitude (and velocity) for checking anti-skate.
     
    Last edited: Feb 11, 2019 at 4:45 PM
  12. BTW, have a look at your blank disc after you have done this. See where the stylus has actually etched the surface? Now think again about how little relevance this method has to how grooves are played by a stylus. The correct way to do this is buy and use a test record with increasing volume mono frequency bands. Listen for distortion in one channel. Adjust anti-skate until the distortion is balanced between channels.
     
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  13. Jimi Floyd

    Jimi Floyd Forum Resident

    Location:
    Italy
    1) as @Davey said flat polycarbonate (CD or laser discs) won't be relevant, as friction on vinyl is different

    2) basic physics tells that once you set anti-skate on blank vinyl you must use 1.4 (square root of 2) times that setting when playing records. This because the stylus have 2 contact points at 45° in the groove.
     
  14. LitHum05

    LitHum05 El Disco es Cultura Thread Starter

    That would actually put me beyond the “3” on the dial (3 is the max).
     
  15. Not so sure about point 2 - a stylus on a blank disc is actually visibly cutting a shallow groove, as the very tip cuts through vinyl. A groove, when played OTOH, has two facets of the stylus played at an approximate tangent to the vinyl modulations in a groove - not even close to the same sort of action, fortunately. Noone wants an extra groove being cut into a records original groove.
     
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  16. Jimi Floyd

    Jimi Floyd Forum Resident

    Location:
    Italy
    That might be...

    In case you want to try a different but effective method, which is valid ONLY if you trust your arm anti-skate device to be linear:
    1) get a test record containing an anti-skating test track with a 300 (or 315 or 330) Hertz tone with increasing amplitude to +12 or +15 db, lateral modulation. I use The Ultimate Analogue test LP
    2) reduce your VTF to something like 1/3, in your case 0.6g. set anti-skate to 1/3 as well. [1/2 could work too]
    3) play that test track and hear which channel breaks up (distorts) first. That's easy to hear. If the left channel distorts first then slightly decrease anti-skate, if the right channel distorts first then slightly increase it, until playing the track both channels break up at the same time.
    4) now bring back VTF to normal, in your case 1.8g, and multiply by 3 your anti-skate setting [multiply by 2 if you chose to test at 1/2 VTF]
    5) repeat the test track and check that both channels break-up at the same time or, even better, they do not distort at all until the maximum amplitude is reached.

    On good arms equipped with good cartridges, mine and my friends', this usually leads to a setting very close to the nominal one. As any other test this is not the end-of-all, but I have confidence in the logic of this procedure. I cannot guarantee it however for crappy or old and rusted anti-skate mechanisms.
     
    John Buchanan likes this.
  17. Jimi Floyd

    Jimi Floyd Forum Resident

    Location:
    Italy
    I never use blank vinyl to set anti-skate, so I cannot reply with confidence. Even if the stylus leaves some visible hairline, I find it hard to believe it is cutting through vinyl though. If it is just marking the surface it doesn't matter, friction theory states that at first order the friction force is independent from the size of the contact area.
     
  18. Bob_in_OKC

    Bob_in_OKC Forum Resident

    Location:
    Dallas, Texas
    I don't think basic physics considers reality. A line contact stylus on blank vinyl is riding on a point with a dramatically different radius than the radii that contact the sides of the groove.
     
    John Buchanan and Aftermath like this.
  19. Leonthepro

    Leonthepro Skeptically Optimistic Autodidact Debater

    Location:
    Uppsala Sweden
    Same.
     
  20. Leonthepro

    Leonthepro Skeptically Optimistic Autodidact Debater

    Location:
    Uppsala Sweden
     
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