Anti-skating

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jimdgoulding

Anti-skating
« on: 20 Mar 2013, 12:29 pm »
What do you bros and sisters do for this?  Some folks use none at all, I believe.  What are the risks and rewards and what and why is your preference.  Thanks.  This is no joke.

BobRex

Re: Anti-skating
« Reply #1 on: 20 Mar 2013, 12:51 pm »
It depends upon the set up and stylus shape.  Twelve inch arms reportedly need less AS than 9 inchers.  According to Van Den Hul, line contacts need less than elipticals.  VDH goes so far to recommend no AS for their carts.

I disabled my AS (Alphason w/ VDH Colibri) and don't hear any negative effects.

jimdgoulding

Re: Anti-skating
« Reply #2 on: 20 Mar 2013, 12:56 pm »
Thanks, Bob.  Since, I've changed decks with a different arm and cart, I've begun to occasionally hear more groove noise in one speaker that the other, hence, my inquiry.  I hope more of you will comment.  Thank you.

NIGHTFALL1970

Re: Anti-skating
« Reply #3 on: 20 Mar 2013, 01:12 pm »
Jim,
there is an excellent video on YouTube by Viperfrank on anti-skating.  Check it out.

http://www.youtube.com/watch?v=eIBtZR941Yw
« Last Edit: 20 Mar 2013, 11:45 pm by NIGHTFALL1970 »

Letitroll98

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Re: Anti-skating
« Reply #4 on: 20 Mar 2013, 03:43 pm »
Jim,
I can't post the URL because I am at work but there is an excellent video on YouTube by Viperfrank on anti-skating.  Check it out.

Not too bad for elementary purposes.  However using the blank disc for setting anti bias force is just plain wrong.

Setting anti bias force is quite like an art form as there is no right answer because the force required changes as the needle traverses across the the width of the record, and it changes according to the velocity the groove is cut with.  For myself I've developed a couple of technics that start with a rough estimation, then using musical tracks to listen for two things, the image height of the orchestra being the same across the soundstage (I actually use a piano recording, but the accepted procedure uses a full orchestral recording), and two, a recording with deep bass or bass percussion far back in the soundstage and in the middle, adjusting for that sound to be directly behind the forward instruments or vocals.

There's also a great article at Vacuum State by the Guru (Rowan McCombe) on cartridge setup, including antiskate (bias).  The whole thing on the alignment gauge he uses is pretty far out there and I don't by any means recommend using it.  However everything else is golden.  Even if you don't use a single thing he recommends, just applying the concepts and methodology will move you forward in your vinyl knowledge base.
http://www.vacuumstate.com/fileupload/GuruSetUp.pdf
http://www.vacuumstate.com/index.dna?rubrik=1&lang=2&a=%252525%251D%25DE%258B%25A5eO%25F3&b=735312.5930328423       

Wayner

Re: Anti-skating
« Reply #5 on: 20 Mar 2013, 04:53 pm »
Using a blank disc is the perfect way to set anti-skate. It's a matter of geometry and physics. While the dynamics of change are constant with an arc sweep of a pivot type tonearm, the blank disc helps to find equal pressures for better stylus contact, thru the sweep of the playable record surface.

What can't be trusted is the dial on your arm. The calibrations have a large +/- of error due to manufacturing tolerances, and anti-skate technique used. Some arms employ springs, others use "dead-man" weight, while others use magnets in proximity to produce the anti-skate effect.

The old AR-XA (XB) tables used fluid damping in the tonearm pivot shaft well to produce the desired anti-skate effect.

I have all 9 8 of my tables dialed in using this technique, and all have benefited from this. My Sony PS-X7's dial is exactly right on, the VPI's AQ PT-6 is slightly less, the Technics SL1200MKII is slightly more.

Incorrect anti-skate adjustment may be the single reason many have issues with Grado cartridge tracking.

BTW, there are even test records with blank areas meant just for this purpose. Some of these records were developed by physicists. If you don't believe the science, then fine. You should let others find out for themselves. It's the only way I'll set anti-skate.

Wayner

neobop

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Re: Anti-skating
« Reply #6 on: 20 Mar 2013, 05:13 pm »
It depends upon the set up and stylus shape.  Twelve inch arms reportedly need less AS than 9 inchers.  According to Van Den Hul, line contacts need less than elipticals.  VDH goes so far to recommend no AS for their carts.

I disabled my AS (Alphason w/ VDH Colibri) and don't hear any negative effects.

That part about VDH is interesting.  Thanks for posting it.

There's prob 1/2 a dozen threads explaining AS.  If you understand how and why, it takes the mystery, or maybe I should say mysticism out of the picture.

Skating is a byproduct of 2 things, stylus drag and offset angle.  Stylus drag is friction plain and simple. Offset angle is the angle that represents the difference between the line from the stylus to the pivot, and the line from the stylus to where the back of the cart is actually pointed.  The stylus traverses the groove on the alignment arc 90o from the offset, but that doesn't coinside with the arm pivot. The result is a force vector that's a combination of 90o from the pivot and 90o from offset.

Because there is no offset with a linear arm, there's no skating.  A longer arm will have less offset to achieve alignment.  Offset angle varies at different parts of the record. The angle increases as the needle approaches the center.  Amount of skating also varies with groove velocity (drag).  Set AS for your normal listening fare. If you set AS for a tympani banging away, but normally listen to vocals, you might have too much AS.
neo

 

BobRex

Re: Anti-skating
« Reply #7 on: 20 Mar 2013, 08:07 pm »
Look like I was confusing VDH and VPI. 
According to the VDH FAQ:
"For conical shapes (somewhat old-fashioned today and only mounted in cheap systems) the anti-skating force setting should
be equal to the tracking force. With more groove-shape adapted stylus designs the anti-skating setting can be less. When
a cartridge uses the VDH type 1 or VDH type 2 stylus, the anti-skating can be adjusted at 1/3 of the tracking force."

So he doesn't recommend no AS, but for his carts a much reduced level than what is considered "standard".  Given that his tracking force recommendation can be lower than 1.5 grams, that makes AS aproach zero (OK .5 grams or less). 

Weisfeld (VPI) is the one that suggests no AS.

JBrahms

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VPI
« Reply #8 on: 20 Mar 2013, 08:17 pm »
I have a circa 2000 VPI 10-inch arm and
'table.   Anti-skating isn't an option, not even available.    I've had a variety of cartridges on this and no issues (except for one defective cart) with sound quality, tracking, etc. 

I also have a Technics 1200mkii that has profound effects when I change the anti-skate.
If it's not set correctly on the Technics I get groove distortion in one channel and mistracking.

Not helpful, probably, but there ya go.

cheap-Jack

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Re: Anti-skating
« Reply #9 on: 21 Mar 2013, 03:54 pm »
Hi.
Look like I was confusing VDH and VPI. 
According to the VDH FAQ:
"For conical shapes (somewhat old-fashioned today and only mounted in cheap systems) the anti-skating force setting should
be equal to the tracking force.

So he doesn't recommend no AS, but for his carts a much reduced level than what is considered "standard".  Given that his tracking force recommendation can be lower than 1.5 grams, that makes AS aproach zero (OK .5 grams or less). 

Weisfeld (VPI) is the one that suggests no AS.

Rather than 'guessing' the best set anti-skating force given any TT already provided anti-skate force adjustment at the end of the tone-am, I'd test it with a blank disc (a disc without any grooves on it).

Many use glass discs to check the AS force correct or not. I refer using a vinyl blank disc though I also get a glass disc. I find a vinyl disc (a DIYed one, modified from a food saucer) resembles the surface friction of our LPs & I find it more accurate.

c-J

Minn Mark

Re: Anti-skating
« Reply #10 on: 21 Mar 2013, 03:56 pm »
For my 'decks with anti-skate (Technics, SOTA and Pro-ject)  I have always used acc'ding to manuf. instructions. The exception (if you will) is my VPI Classic I. While it comes with an anti-skate, I do not use it, never have tried it. In my experience it's a great 'table and I do not miss any anti-skating on it.

Cheers,

Mark

a.wayne

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Re: Anti-skating
« Reply #11 on: 24 Mar 2013, 07:34 pm »
Using a blank disc is the perfect way to set anti-skate. It's a matter of geometry and physics. While the dynamics of change are constant with an arc sweep of a pivot type tonearm, the blank disc helps to find equal pressures for better stylus contact, thru the sweep of the playable record surface.

What can't be trusted is the dial on your arm. The calibrations have a large +/- of error due to manufacturing tolerances, and anti-skate technique used. Some arms employ springs, others use "dead-man" weight, while others use magnets in proximity to produce the anti-skate effect.

The old AR-XA (XB) tables used fluid damping in the tonearm pivot shaft well to produce the desired anti-skate effect.

I have all 9 8 of my tables dialed in using this technique, and all have benefited from this. My Sony PS-X7's dial is exactly right on, the VPI's AQ PT-6 is slightly less, the Technics SL1200MKII is slightly more.

Incorrect anti-skate adjustment may be the single reason many have issues with Grado cartridge tracking.

BTW, there are even test records with blank areas meant just for this purpose. Some of these records were developed by physicists. If you don't believe the science, then fine. You should let others find out for themselves. It's the only way I'll set anti-skate.

Wayner

+10

jimdgoulding

Re: Anti-skating
« Reply #12 on: 24 Mar 2013, 08:28 pm »
Wayner, entertain a dumb question . . is the blank disc running while you lower the cartridge?  Should the cartridge stay put?  Thanks.

Btw, my newly mounted Koetsu running on another table is tracking at what I set to be 92 degrees and it's seriously wonderful.
« Last Edit: 25 Mar 2013, 12:13 am by jimdgoulding »

Wayner

Re: Anti-skating
« Reply #13 on: 25 Mar 2013, 11:44 am »
Yes, the disc is running.

Wayner

jimdgoulding

Re: Anti-skating
« Reply #14 on: 25 Mar 2013, 08:21 pm »
Wayner, hey man!  I asked you for some clarification here and you haven't replied.  You shining me on, ggod sir?  I hope not tho it wouldn't be the first time my mouth got me into trouble.  Let me say right now that I would regret having given you a reason if I have.  You are a very knowledgable fellow and an asset to me.  I tried sending you this message in a PM but you no can recieve.  What up with that?

neobop

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Re: Anti-skating
« Reply #15 on: 25 Mar 2013, 09:07 pm »
Jim,
Analogue Productions AS test is a 315Hz amplitude sweep to +12dB, in both channels. You can adjust by ear so there is no break up, or break up occurs equally in both channels.
neo

jimdgoulding

Re: Anti-skating
« Reply #16 on: 25 Mar 2013, 10:08 pm »
Thanks, Neo.  All I've ever used is my ear and common sense.  I think I'm in the pink right about now.

BobRex

Re: Anti-skating
« Reply #17 on: 26 Mar 2013, 12:57 pm »
The idea of using a blank disk for setting AS has been "de-bunked" by many.  Here is Van Den Hul's take on it:
"NEVER use an unmodulated record surface to adjust the anti-skating: This is static replay without the normal friction
between the groove and the stylus, so don’t use this way of setup. The result is always a too low value and your
violoncellos will distort again."

Do a google search on "Setting anti skate with a blank disk" and you will get a number of others who agree with the above.  Very few agree with using the blank disk.

Scottdazzle

Re: Anti-skating
« Reply #18 on: 26 Mar 2013, 02:37 pm »
For my 'decks with anti-skate (Technics, SOTA and Pro-ject)  I have always used acc'ding to manuf. instructions. The exception (if you will) is my VPI Classic I. While it comes with an anti-skate, I do not use it, never have tried it. In my experience it's a great 'table and I do not miss any anti-skating on it.

Cheers,

Mark

I've used my VPI Classic with and without the anti-skate. I could not hear any difference. Perhaps a fozgometer would show a difference that I can't hear, but I'm not spending $250 to find out. The anti-skate is disengaged at least until I change cartridges.

Ericus Rex

Re: Anti-skating
« Reply #19 on: 26 Mar 2013, 03:13 pm »
The idea of using a blank disk for setting AS has been "de-bunked" by many.  Here is Van Den Hul's take on it:
"NEVER use an unmodulated record surface to adjust the anti-skating: This is static replay without the normal friction
between the groove and the stylus, so don’t use this way of setup. The result is always a too low value and your
violoncellos will distort again."

Do a google search on "Setting anti skate with a blank disk" and you will get a number of others who agree with the above.  Very few agree with using the blank disk.

If your anti-skate setting is way off a blank disk will help you get closer.  Then you fine-tune by ear to get it perfect.  A lot of people have strong feelings against its use, period, but I think it can be a helpful tool.