On anti skating

[phhphd]

I have always believed that anti skating was absolutely necessary. Then I really looked at my brother's old Empire turntable (598 I think) and .. no anti skating. I bought an old Onkyo turntable at a garage sale (multiac 60) with a beautiful but old tonearm and .. no anti skating. The coup de gras was when I looked at the instructions to my Grace 747 unipivot tonearm and could find no anti skating adjustment. Did I miss it on this last one?

So, how necessary is anti skating? How did these older designs work?

Patrick

 

[goldear]

I have always believed that anti skating was absolutely necessary. Then I really looked at my brother's old Empire turntable (598 I think) and .. no anti skating. I bought an old Onkyo turntable at a garage sale (multiac 60) with a beautiful but old tonearm and .. no anti skating. The coup de gras was when I looked at the instructions to my Grace 747 unipivot tonearm and could find no anti skating adjustment. Did I miss it on this last one?

So, how necessary is anti skating? How did these older designs work?

Patrick

Antiskating is definitely desirable, but is not strickly required. Many older arms lacked this feature. And, unfortunately, it is nearly impossible to implement antiskating on a unipivot design.

FYI- The Grace 747 is gimbled design rather than a unipivot. Perhaps you are thinking of a unipivot Grace 704, or 714?

 

[Karma16]

Antiskating is definitely desirable, but is not strickly required. Many older arms lacked this feature. And, unfortunately, it is nearly impossible to implement antiskating on a unipivot design.

FYI- The Grace 747 is gimbled design rather than a unipivot. Perhaps you are thinking of a unipivot Grace 704, or 714?

HI Jim,
What you said is only sometimes true. For example, my Graham 2.2 Deluxe unipivot arm which is mounted on my Oracle Delphi turntable has anti-skating compensation.

To the OP: Anti-skating is a refinement rather than a necessity. If you add up all the forces acting on the stylus tip while tracking a record it demands a vertical tracking force that permits tracking without mistracking. Part of the tracking force is assigned to keeping the skating forces from lifting the stylus out of the groove as it rides the inside groove edge and thus causing mistracking. If you do a force vector analysis you will find that skating force is translated into an upward force that subtracts from the VTF. Thus, the VTF must be increased to compensate.

By compensating for the skating force using a horizontal force application system (parallel to the record surface) the force on both sides of the sylus is equalized (sort of). As a result the VTF can be reduced without causing mistracking since it no longer has to contend with skating force. Obviously, there are limits beyond which the VTF cannot be further reduced.

Another factor is stylus wear. Uncompensated skating force add significant force to the inside edge of the stylus. This causes accelerated stylus wear. I can back this up with almost countless stylus examinations with my Shure purpose built high magnification stylus microscope.

Because skating force is largely determined by the friction between the wildly modulated groove and the stylus, and it always pulls to the center of the record, the cartridge suspension system is always pulled off-center. And because the friction is constantly changing as determined by the instantaneous grove modulation, skating force is constantly changing. Thus, anti-skating compensation is never exactly right. Rather, the best you can do is compensate for the average skating force. Because of this, a very strong argument can be made for a tone arm geometry that does not create skating force in the first place. This is found only with linear (non-pivoted) tone arms.

Uncompensated skating forces also causes the inside side of the groove to wear faster than the outside thus increasing noise and distortion with use.

All in all, I consider anti-skating compensation an absolute requirement for any high performance pivioted tone arm. This is true unless you have a linear tracking arm, such as Jim and I have, the ET-2, which creates no skating force due to its geometry.

Sparky

 

[RWFE]

I have a VPI Scout that came with the anti-skating attachment but I have trouble hearing the difference with and without. The physics of the necessity for it makes perfect sense to me but I have been unable to detect a difference in the real world when I try.

 

[Mopic5]

Anti-skate is also incorporated on both the Sonus and Mayware Formula IV unipivots. (Thread bearing shot filled buckets - anchored to the two o'clock positions of the unipivot's containment shells - on plane with pivot point.)

 

[gkimeng]

So, how necessary is anti skating? How did these older designs work?

Patrick

I have an original AR turntable that has been working quite well without anti-skating for the past 47 years and hasn't worn out a record yet.

 

[goldear]

Well Sparky, I stand corrected! But while I completely agree that it is a requirement for any really high performance pivoted arm, I've run across some very nice sounding older arms (like the grace 704) which lacked it.

 

[phhphd]

This has been great so far. I stand corrected. My tonearm is indeed a Grace 704. I bought the turntable (LUX PD 121) with arm and cartridge so I did not deal with the set up until I became curious. Thanks everyone, but I have to admit I'm not sure now how I feel about the issue. My brother is going to give me the Empire 598, a beautiful gold turntable, and I'd hate to be afraid to use it.

Patrick

 

[goldear]

This has been great so far. I stand corrected. My tonearm is indeed a Grace 704. I bought the turntable (LUX PD 121) with arm and cartridge so I did not deal with the set up until I became curious. Thanks everyone, but I have to admit I'm not sure now how I feel about the issue. My brother is going to give me the Empire 598, a beautiful gold turntable, and I'd hate to be afraid to use it.

Patrick

While the empire arm certainly is not a high performance arm, I don't think that there is a reason to be afraid of using the empire. That is, unless the arm is a complete POS, and/or the bearings are having problems. The worst thing that will happen (with a properly functioning, semi-decent arm) is a little more disortion out of one channel, and a stylus which will wear unevenly, and which may not last quite as long.

 

[Rybeam]

I agree with the hard to hear comments. Try putting on a poor sounding album. Listen close and you can hear the static increase in the left channel as you increase the anti skate. Sometimes !

 

[ManFromPorlock]

Dumb question, but couldn't you compensate for a lack of anti-skating by tilting the TT? Or would there be unintended consequences?

 

[Daravon]

I think anti-skating is silly. I understand the principle perfectly (I'm a physicist) but I believe all the other variables involved overwhelm this trivial consideration. I have looked at turntable signal output while fiddling with anti-skated and determined that the variation between records is greater than anything anti-skating purports to do.

 

[Fred Longworth]

I believe it was in 1979 that physicist Stanley Lipshitz wrote an article for the JAES explaining the mechanics of anti-skate,and further explaining why a linear-tracking arm not only does not require anti-skate but theoretically does not generate intermodulation distortion.

I am no fan of arms that lack anti-skate. Many of them simply use a variant of the crude "penny taped on the arm" method.

Fred

 

[bordeno]

Dumb question, but couldn't you compensate for a lack of anti-skating by tilting the TT? Or would there be unintended consequences?

Not a dumb question at all. It would have to be tilted diagonally. Sort of from the left rear down to the front right. Actually it might not be a bad idea, but then you'd get into calculating how much tilt and all that crap and don't think anyone'd get to that point. Most would dismiss the idea simply because its unconventional.

Anyone try this?

 

[Nat]

I believe that antiskating is more important if you are tracking at the lower end of the tracking force range (and probably, if your arm has really low friction). AR used to argue that an extra 1/4 gram of tracking force would have the same effect, and I don't know if that's exactly true, but a bit of extra weight often is a good thing. AR also suggested twisting the tonearm leads on the XA to give some antiskating, so they weren't against it. But plain old friction (which old arms usually have) provides some resistance to skating force -- I remember B&O used to use a ball and wedge arrangement to provide something similar.

 

[gkimeng]

I believe that antiskating is more important if you are tracking at the lower end of the tracking force range (and probably, if your arm has really low friction). AR used to argue that an extra 1/4 gram of tracking force would have the same effect, and I don't know if that's exactly true, but a bit of extra weight often is a good thing. AR also suggested twisting the tonearm leads on the XA to give some antiskating, so they weren't against it. But plain old friction (which old arms usually have) provides some resistance to skating force -- I remember B&O used to use a ball and wedge arrangement to provide something similar.

I have four different editions of the AR turntable owner's manual. The first three editions, which address the TT, TX and TA two-motor tables, say nothing about the twist of the tonearm lead. The fourth, for the XA, has a photo of the lead bent in the familiar C-curve and just says be sure the wire is bent like that, no reason given.

In the section on stylus force, the manual says nothing about skating, and merely states that low tracking force is not indicative of better cartridge quality and that a bit more force than recommended is better than a bit less. The design philosophy of the table was always to simplify things as much as possible for the user, and I imagine this extended to not mentioning things that the designers had concluded were negligible.

 

[Nat]

The comments about tracking force and antiskating were made in either interviews or in articles they (Vilchur or Allison or Curl or whomever) wrote, and I'm not surprised that they didn't get into it in the owner's manual -- the 'if it ain't broken, don't fix it' attitude they had probably included not bringing up issues in the owner's manual that would raise doubts as to the design -- presumably if someone bought an AR, he either already knew about the issue and their stance, or had no idea that the issue existed, in which case to point it out would simply cause trouble.

 

[rockets63]

Empire 598

I have always believed that anti skating was absolutely necessary. Then I really looked at my brother's old Empire turntable (598 I think) and .. no anti skating. I bought an old Onkyo turntable at a garage sale (multiac 60) with a beautiful but old tonearm and .. no anti skating. The coup de gras was when I looked at the instructions to my Grace 747 unipivot tonearm and could find no anti skating adjustment. Did I miss it on this last one?

So, how necessary is anti skating? How did these older designs work?

Patrick

The Empire 598 has a pretty sophisticated Vernier anti-skate system but many have been disabled over the years. I own a 598 as well another 598 (990) tonearm mounted on an Empire 398 turntable. I take exception with the statement that the 598 arm is not a high performance arm, it was near the top in its day and was the inspiration for the Fidelity Research arms. The dynamic balance makes it usable with both high and low compliance cartridges. I believe anti-skate is an improvement but not absolutely necessary. I know this is an abandoned thread but I had to add my 2 cents anyway.

 

[WaynerN]

I have an Empire 598MKII table with the 990 arm. The spring that activates the AS apparently has "weakened" so the AS is not quite as it should be. Rotating the arm base has helped this as it puts the AS spring in a stretcher position.

I also have the AR turntable. While it does not has the traditional AS, it in fact does have AS thru the use of the oil damping in the arm pivot well, and the lead wires from the tonearm to the base.

The more VTF applied, the more AS is required (to a point). You could always tape a quarter to the arm head to overcome the skating tendency.......

 

[Bill Stevens]

Anyone interested might want to query Harry Weisfeld, owner and founder of VPI, who does not care much for anti-skating. He says he can hear it working. No question on a warped record anti-skating might be audible. Anti-skating can be avoided by adding a bit of vertical tracking force. Say add ~ 0.25 grams. I believe the comment relating to lighter tracking forces has merit, but would caution that every stylus that I have ever examined used on a arm without anti-skate has worn unevenly, with more wear on the inside of the stylus than on the outside. Too, I have records in my collection that were played originally on Weathers (i.e. very lightweight wood tone arm, no ant-skate) others records on my first "upgrade" AR (high mass, high friction arm, no anti-skate), others on my next "upgrade" Dual 1219 (low mass arm with anti-skate), later on a Thorens TD125 first with Rabco SL8R (medium mass tangential tracking arm) and later SME 3009 Series II and...well I could keep going but you get the idea. Playing my old records again, some hadn't been touched in years, provides insight into what different record wear patterns have occurred with different equipment. Generally, I can say that the records first played on anti-skate equipped arms (as well as SL8E) seem quieter and show less wear. By the way, today I own a Wild-Heerbrugg microscope and regularly check stylii for wear. Additionally, years ago during the 1970s I was in the business and as such set up a lot of turntables and examined a lot of cartridges in addition to my own. So these comments are more than just anecdotal.