Sliding force???

[jadis]

Here is the entry from my V-12 manual. Pretty basic advice.

The dial is hard to turn because it is filled with I think silicone to dampen the spring coil. I don't know where the end of the spring attaches. Nor do I remember where I read that the AS dial is calibrated to be 2/3 of the VTF value. The manual does state that proper AS depends on a number of factors. Offset angle (arm length), groove modulation, VTF, stylus location on record, etc. Any setting you choose will be a compromise. I had matched the two dials as recommended in the manual, but the Schoder/Lederman deadwax test gives me different results. Both settings sound good but slightly different. I don't hear any clear distortion either way. Listening to a variety of LPs will be the final test for me.

For reference, the deadwax test setting has the dial at the letter A or about 0.5g. I don't understand the graphic symbol between 0 and "Anti".


View attachment 56094

Just a thought re the dial setting of PeterA. 0.5 was the dead wax test setting for his SME tonearm. My Linn Akito needs to be set at 2.5 to be at that same level. I am thinking now the difference is pretty big, from arm to arm. So the numbers cannot be in 'grams' as in the VTF. And arm makers makes these numbered dials like they are 'standard', as in weight of the VTF and I think they are not. So all the more there is a need for some 'standard' in determining the correct AS setting. If not, then our ears will be a critical judge for it. Start a 0, and work onwards by listening to familiar tracks, imo.

 

[assessor43]

I am finding 0 antiskate to work well with the Lyra Delos on my table, a 1200G. Sometimes on some rock stuff I will increase it to just under .50.

 

[jadis]

I am finding 0 antiskate to work well with the Lyra Delos on my table, a 1200G. Sometimes on some rock stuff I will increase it to just under .50.

I am still at 0 AS as well, not finding the need to add anything yet, and keenly watching the straightness of the cantilever. I'm thinking my max someday if I find the need should be fractions of 0.50.

 

[Catcher10]

So the first track gets louder as the instructions say; not sure I am hearing distortion either way.

The second track is more interesting and the sound does drop in mono by about 10dB with anti skate and about 8dB without. I cannot get it to go completely silent. I am not sure that’s even possible when channel separation cannot be infinite ?!?!

I have the same test record, I listen to the first track thru headphones....about 3 seconds before end of track I hear a very faint buzz. Not sure that equates to mistracking, before that I hear absolutely nothing. I've played with AS on my arm but no change to that last 3 seconds......I'm not concerned as I only hear it thru headphones with volume set to 2 o'clock, which is not normal level for me.
I don't have an o-scope so not sure what I am hearing....The 2nd track not sure means anything to me without an o-scope...

 

[ack]

Just wanted to throw in here a quote from Michael Fremer from the October 2019 Stereophile (in a Haniwa arm review), to point out that we are really dealing with two different forces, as we have discussed in this thread:

While much of the cause of skating is the offset angle - since the arm's pivot is offset from the cantilever instead of directly behind it, the frictional drag produces a force vector that pulls the arm inward - there's a secondary skating force set up by the lack of groove tangency produced by the stylus's arc of travel across the record surface.

While using a blank record is not the correct way to set anti-skating - the amount of frictional drag produced when "tracking" a smooth surface is far less than what a stylus would encounter in a typical grooved record - it certainly is useful to demonstrate that, despite the lack of an offset angle, the arm skates.

 

[PeterA]

Ack, it is interesting that my tonearm manufacturer and my cartridge manufacturer each recommend different settings. One is at 1.5g and the other is at 0.2-0.4g. I listened to both as they represent the extremes of the range. I then adjusted by ear for what sounds best. The setting is now between the two recommendations. I suspect it may change as the cartridge suspension breaks in a bit more, as will the VTF. It is worth noting that skating force varies with arm length because the offset angle is reduced the longer the arm.

 

[ack]

Cartridge manufacturers cannot possibly know which arm one will use, therefore, I suspect they quote anti-skating from the cartridge's perspective; ditto from the arm perspective. So no surprise you ended up somewhere in between. Having said that, 1.5g seems excessive whichever way we look at it...

 

[jadis]

Cartridge manufacturers cannot possibly know which arm one will use, therefore, I suspect they quote anti-skating from the cartridge's perspective; ditto from the arm perspective. So no surprise you ended up somewhere in between. Having said that, 1.5g seems excessive whichever way we look at it...

Agree, Tasos.

As I begin to understand the principles behind (or against AS force), I still have 2 questions that I need to be clear on, as the standard recommended AS value is usually pegged at your cartridge's VTF. Example: 1.80g VTF = 1.8 AS (note, I am not sure if this AS dial is in actual grams, as in weight grams) on a dial with a 0-2 AS adjustment.

1. As indicated above, what is the real value or meaning of a 1.80 value on a rotary AS dial? Does it correspond of the same 1.80 grams of a gravitational weight?

2. Assuming an arm, like the VPI, does not a 'dial or rotary' AS scale, but a small deal weight in a string attached to the near end of a tonearm, what is the gauge of any movement, or adjustment of the dead weight on a string? What increments to move it about on the end of the tone arm wand? How do we know at what point is the AS 'correct'?

My foremost concern now regarding AS adjustments is the balance between a 'good or correct' sound (as mentioned in these pages already) vis-a-via the perpendicularity of the cantilever when viewed from from front of the cartridge's body. Like the 'straightness' of the said view of the cantilever should not be canted either toward in the inside or the outside of the record. To give a clearer example, when my Linn Akito 3b's AS was set to 1.80 (corresponding to the Koetsu Urushi's 1.80 gram VTF), I found the sound of vocals (more noticeably) having more body than if the AS was at 0. I know this is radical but at the 1.80 AS setting, the cantilever of the Koetsu in canting inward, or towards the spindle. Actually, I used this setting (not too conscious about it then) for 7 months then I noticed that when at the arm rest, the cartridge now really is canting slightly to the inside. If I still use this setting for a year or 2, I probably will be seeing a severely canted cantilever, to the inside. By this time, I believe that there will be mistracking happening in some parts of the LP. But at 0 AS setting, I should say the open-ness of recording is far better than at 1.80 AS but with a 'leaner' tonal balance. So after using the 0 AS value for 3 months, I now observed that my cantilever is tracking dead straight when viewed from that front, and even in the arm rest, it looks pretty straight. As to when I will add some more AS, I am still deliberating. All I want to happen is to add some more AS (a teeny bit, as I have read) and get more 'body' in the mids, while still seeing my cantilever tracking perfectly straight down. In the meantime, I seem to have struck a good compromise in having 0 AS by adding 0.10 g to my VTF. There is still some uncharted territories ahead.

 

[ack]

Hi Phil,

1) whether the AS dial in your arm represents true force indicators or not: I would say the arm manufacturer and/or manual is the only true source for that information. I am not even sure how one would measure this, either; and I would tend to think the cartridge weight and position of the VTF counter-weight would influence such a force. In other words, kinda hard to believe the markings on your AS dial represent true force in grams

2) On my VPI arm, I move weights along that anti-skate arm, until I get the lowest distortion by ear; the thread has been glued at the highest possible position. A very good reference for that was the video you posted, which says that one should aim for slow inward movement around the deadwax area. I personally found this to be an eye-opener. Also see what was posted months ago about using test records to determine lowest possible distortion.

The one thing that has been proven to me beyond any reasonable doubt is that skating and sliding forces introduce clearly audible distortions, and must be countered - this is in sharp contrast to what VPI has been claiming for years.

 

[PeterA]

Hi Phil,

1) whether the AS dial in your arm represents true force indicators or not: I would say the arm manufacturer and/or manual is the only true source for that information. I am not even sure how one would measure this, either; and I would tend to think the cartridge weight and position of the VTF counter-weight would influence such a force. In other words, kinda hard to believe the markings on your AS dial represent true force in grams

2) On my VPI arm, I move weights along that anti-skate arm, until I get the lowest distortion by ear; the thread has been glued at the highest possible position. A very good reference for that was the video you posted, which says that one should aim for slow inward movement around the deadwax area. I personally found this to be an eye-opener. Also see what was posted months ago about using test records to determine lowest possible distortion.

The one thing that has been proven to me beyond any reasonable doubt is that skating and sliding forces introduce clearly audible distortions, and must be countered - this is in sharp contrast to what VPI has been claiming for years.

Tasos, yes this inward slow movement is interesting. I tried it which is what started me on my careful listening sessions. At the SME recommended VTF=AS, the arm was basically motionless. At the vdH recommended AS, it moved inward fairly quickly, but slower than 0 bias. So, both recommendations seemed wrong, but I also noticed inconsistency with different records, both 33.33 and 45. So, I did not find this method all that useful. It did get me to find a middle ground between the two extremes and that was confirmed by listening. I mean, what is the right amount of "slow" movement in the deadwax area? I guess, it is a starting point, but listening was the best method for me.

I also wonder if speed makes a difference. There is more friction at 45 rpm. Would that not mean a higher skating force?

 

[ack]

I mean, what is the right amount of "slow" movement in the deadwax area? I guess, it is a starting point, but listening was the best method for me.

No disagreement; it is a great starting point, ear is the ultimate judge

I also wonder if speed makes a difference. There is more friction at 45 rpm. Would that not mean a higher skating force?

I have no idea, but it's a great question!

 

[jadis]

Good points, Tasos and Peter. I guess as long as we do not hear distortions anywhere in the record, that is a good thing, to start with. We just showed things can be subjective with AS, unlike VTF which is a simple gravitational weight setting. So, there are some more new questions, like speed.

 

[jadis]

I thought of reading up on one of the top tonearms - the SAT, as to how its designer attacks the Anti-Skate issue.

"Despite the high-tech materials, operating and adjusting the SAT arm are more traditional. The antiskating mechanism is a filament/weight system, the filament's looped end fitting over a tiny rod that protrudes from the side of the horizontal bearing housing, which is shaped like a flattened O. The filament rides on a thin, grooved cam attached to the top of this housing, then over a tiny wheel riding on an axle of equally small diameter protruding from the rear of the vertical bearing housing. A small weight attached to the free end of the filament produces the antiskate force. Supplied washers can be attached to the weight to increase the antiskate force.
But while the antiskate system's mechanics look traditional, Gomez says his design maintains "constant torque" across the entire surface of the record; many other system, he says, do not follow the actual geometrical variation of linear offset as the arm traverses an LP. While skating is affected by many uncontrollable factors—eg, degree of groove modulation, vinyl formulation, stylus profile, tracking force—Gomez says that consistency of antiskating torque across the entire LP side is still desirable and achievable."



Read more at https://www.stereophile.com/content/swedish-analog-technologies-tonearm#eSpeI8zgCxzQ75Fi.99

 

[jespera]

Heres something to think about: is the advantage of 12” arms and parallel
trackers due to less tracking angle error or the fact that they are less sensitive or imune to (dynamic) antiskating forces?

Personally, i think the latter.

Has anyone tried the japanese arms with zero offset angle?

http://www.sibatech.co.jp/viv/rf.html

Jesper

 

[jadis]

At yesterday's Manila audio show, I was able to ask some questions about AS from the German designer and owner of Acoustic Signature turntables and tone arms. Basically he said things that we've heard before. Don't use blank lps, use real records to listen to distortions, left or right. Add some tracking force if necessary. Zero AS is ok if you do not hear distortion. Look out for bending of cantilever in or outward, as it results in permanent damage to the cartridge. And he makes many tone arm models, some with weight and string AS, some with dial. For dial, it is not in grams, but normally should be lower or half of VTF.

 

[jadis]

Btw, forgot to mention that by the end of the discussion, Gunther said that Anti-Skate is 'MAGIC'.

 

[Mike Lavigne]

i think that Joel Durand has a good grip on Anti-skating force, and uses strings and weights. the top two photos are of my unipivot Durand Telos Sapphire tonearm, and the next two are the "new this year" gimble bearing Durand Tosca tonearm. then the bottom picture is my brand new CS Port linear tracker. this LT might be the only one with a low pressure low flow air bearing which brings to the table seemingly a high degree of freedom from any aspect of tracking force distortion. higher than other linear trackers. the sound is amazingly ultra-pure and settled.

https://whatsbestforum.com/threads/...-added-to-the-system.29451/page-7#post-610183

 

[PeterA]

Nice photos, Mike. On the Durand arms, is there calibration markings so that the user knows how much AS he is applying? I see the adjustable weights and rubber washers to adjust the amount of force, but how does one know how much is being applied?

Having followed the development and evolution of your various Durand arms over the years, it is clear that Joel Durand has a fertile mind. I wonder if he is considering designing a linear tracking arm. What I like about the CS Port arm is that the armwand and counter weight look somewhat massive. I suspect these help to deal with resonances that lighter arms have trouble with. This may account somewhat for the superior bass performance of this design versus some other LT arms. Just a guess. The bearing implementation looks superb and what looks like the arm lifting mechanism sure seems robust.

 

[Mike Lavigne]

Nice photos, Mike. On the Durand arms, is there calibration markings so that the user knows how much AS he is applying? I see the adjustable weights and rubber washers to adjust the amount of force, but how does one know how much is being applied?

you can adjust the position of the rubber washer, there are different weights at the end of the string on the Telos, as well as different weights on the pivot shaft as well as position on that shaft. so lots of variables. the Tosca is similar but the weight is on the rotating counterweight. i've not seen numbers to predict which weight to use, it's done by listening. obviously more weight for the heavier cartridges.

Having followed the development and evolution of your various Durand arms over the years, it is clear that Joel Durand has a fertile mind. I wonder if he is considering designing a linear tracking arm.

i doubt it and have heard nothing. it's never come up. i think traditional linear trackers are rare because implementation is daunting. mostly requires an air bearing at the top of the food chain (and why bother unless you are shooting for the stars).

What I like about the CS Port arm is that the armwand and counter weight look somewhat massive. I suspect these help to deal with resonances that lighter arms have trouble with. This may account somewhat for the superior bass performance of this design versus some other LT arms. Just a guess. The bearing implementation looks superb and what looks like the arm lifting mechanism sure seems robust.

in that 'zen' Japanese way with the CS Port every part is appropriately robust, or gossamer delicate. the arm lifting mechanism is well executed and confidence inspiring. i can leave the arm at any vertical position and it stays, that part has a very nice smooth feel. 'almost jeweled' in it's silkiness.

to me the delicacy and 'touch' of the arm is it's soul, but agree it's got weight and bass authority plenty. not the last word in slam or explosiveness, but enough to bring balance to the music. i have the Saskia and NVS for uber levels of those things.

Mik talks about that the unique approach to air pressure sets it apart.

 

[PeterA]

you can adjust the position of the rubber washer, there are different weights at the end of the string on the Telos, as well as different weights on the pivot shaft as well as position on that shaft. so lots of variables. the Tosca is similar but the weight is on the rotating counterweight. i've not seen numbers to predict which weight to use, it's done by listening. obviously more weight for the heavier cartridges.

Mike, do you mean cartridge weight or VTF? I think cartridge weight is compensated for by the arm's counterweight and basically the system is balanced until VTF is applied, independent of an individual cartridge's weight. Effective mass may be slightly more with heavier cartridges, but I think Anti-Skate or bias is more in response to the vertical tracking force being applied by the stylus onto the record.