Anti skate. I think something's wrong


I have an Acoustic Signiture TT with a Graham 2.2 tonearm and Ortofon Cadenza Bronze cartridge. My anti skate is set close to tracking weight and it would always dig to in inside when I would start a record. I read this is wrong so I got my Cardas test record out and placed it in smooth section and it imediately gravitated to inside. I adjusted anti skate to where cartridge slighty pulls to inside . Here is the problem. To get this I'm having to adjust anti skate to the max. I rechecked TT and it is right on level wise. I have less sibilence now and swear the two channels are more even. The right channel has always been just slightly lower than left in volume. The only qualm I have is the max antiskate I have to use. Is bearing bad? I have the blue fluid. Or I shouldn't worry and enjoy the music. Mike
blueranger
On my SME 309 and Grado cartridge I have the anti-skate set to one gram higher than the tracking force. The anti-skate will be different depending on the stylus shape of the cartridge.  
The bottom line is don’t worry about it and enjoy the music!

Is the left channel still stronger?

Seems like your AS calibration is weak. You shouldn't be maxed out on the dial. If it's still not centered, you should get it fixed, IMO.

Anti skate and channel balance should not be not related, if that is what you mean by stronger on one side.  How many hours do you have on the cadenza?  Has this combo always reacted like this while together?

It is a little odd you have to use maximum AS setting but if it works just enjoy the music.  
For the best sound you shouldn't use the a/s at all.  I never use it.
I got my Cardas test record out and placed it in smooth section and it imediately gravitated to inside. I adjusted anti skate to where cartridge slighty pulls to inside .
If, as I assume, when you refer to the "smooth section" of the test record you are referring to the ungrooved sections it has, keep in mind that when "playing" an ungrooved surface the skating forces that would result when the stylus is in the groove of a rotating record are not present. Therefore I suspect that the amount of anti-skating force that is being applied is still too low. Although not being familiar with the arm I have no idea why that may be, given that you have set the anti-skating to max.

One thing I would do, if you haven’t already done so, is to view the cartridge head-on (from the front) while the stylus is in the groove of a rotating record, and see if the cantilever is visibly deflected (probably to the right, toward the outside of the record), relative to its position when the stylus is lifted off of the record (presumably straight ahead, or close to it). If deflection to the right is evident it would confirm that for whatever reason your anti-skating force is still too low, IMO.

Good luck. Regards,
-- Al

Did you remove the protection cap from the bearing tip?
Oh what's that??? What's it look like?

One some test records there is a blank piece at about 5 cm.

''Blank'' means without grooves. One can adjust anti-skate

at this place on the record such that tonearm remains stationary.

Aka not moving to the inside or outside. This was the old way

to adjust the anti-skate. By increasing the anti-skate force one

can increase the tracking ability of the used cart. But there is 

no sense in increasing tracking ability above, say, 60 microns.

60 microns is sufficient for the cantilever/stylus combo  to trace

 any record. The mentioned ''blank piece'' one can use as a kind

of indication  for further adjustment which should consist in reduction

of the anti-skate force . Either by listening or by adjusting till

60 microns value is reached. The advice is to use the minimal anti-

skate force. This is not my advice but advice from Van den Hul.

The advantage of such test record is that one can see how

anti-skate actually works.

 

P.S to my previous post:  To be precise, the last sentence of my previous post should read as follows:

If deflection to the right is evident it would confirm that for whatever reason your anti-skating force is still too low, or for whatever reason skating force is too high.  IMO.

Also, I've found over the years that optimal anti-skating force usually corresponds to about 50% to 60% of the tracking force.  Other opinions and experiences will differ.

Regards,
-- Al
 
You say there's always been difference in output between the channels? This would indicate that the azimuth is incorrect for starters...(I haven't read all in detail so may be already mentioned - just wanted to mention this important step). Also, be sure to use a correctly calibrated electronic scale for VTF (down force). 
My right channel is always the one that clips first. Bryston was fried during lightening storm and was sent back to factory where they replaced all caps plus other things. Seller told me this when I bought it. he also told me it was a 14bst and not a 
14bsst. Factory were out of 14bst switches for front and they used 14bsst . At this time I was researching and by my serial number Bryston had incorporated most of the sst changes. David Tanner said in the late serial numbers the sonic differences by ear were not detectable. If it hadn't been a happy time in my life I probably would have voided sale. Sorry to get off topic. Mike
There is no way to measure/adjust anti-skate properly...it is a constantly changing force, and is so small that it is unnecessary. It only distorts the tracking of the arm...provides unnecessary damping .....not for me.
Dear blueranger: Nice system you own.

You said that have an unbalnce in the volume/SPL, that the right channel sounds louder. This is not an AS problem but as other gentleman here suggested the Azymuth set up but if the cartridge/tonearm overall set up is " right " about VTA/SRA/AZ and tonearm damping fluid and the problem stay then problem could be in the electronics in one of the system components, it's not probable a speaker unbalance per se.

Forgeret about the AS and clean up any single male and female connector in the whole audio system looking too that no one connection/cable/wire is loose, including the ones in the cartridge/tonearm wires and speakers and the electrical cables too. If all these don't fix that problem then the unbalance is on the electronics.

Out of the subject of your thread but looking your system and only as an idea ( don't to fix your today problem. ) and do that your system seat is so close to the back " wall " a damping pannel here can improve your quality listen sound. 

Regards and enjoy the music,
R.
I have a Graham 2.2T. I agree with the posts by Almarg on how to adjust AS. It may help to first verify with no AS and no tracking force applied that the arm is not being forced to the outside by anything such as a twisted tone arm wire or connection.
It's been awhile since I did anti-skate, but I remember one thing.  Do not use anti-skate for any other reason(like channel balance) than what is the best setting for the just the anti-skate alone.  I think you get close to the correct anti-skate, and then, incrementally go forward and back(more and less anti-skate), until you hear what anti-skate does.  You can go slow, and even sleep on it.  If, the next day, you are less excited to want to listen to your records, put it back where you had it, etc.  I vaguely remember that it might be just less(a slightly smaller amount of anti-skate) than where the balance between channels(or something like that) is best.  There was a discussion on here, where I came to the same conclusion as a person who studied anti-skate a lot. Note:  all of my anti-skate experiments were done with gimbaled tonearms(but I would assume you could use the same experiments. I think uni-pivots[the Graham, I assume] use less anti-skate.).  To get a starting point, you might research your tonearm and cartridge(reviews, etc.).  In addition, your choice should be for the best sound(again don't listen for specific things) for the whole record, while you can keep in mind that anti-skate should be more needed towards the end of the record(I think there might be a few more compromises towards the end-even if you get the correct setting.).  
Are you absolutely 100% sure your platter is perfectly level? How about where you mount your tonearm - is that perfectly level, too?

Check it, and recheck it. My table is on a wooden cabinet and "level" changes day-to-day (I tweak with pieces of card stock under the footers). No need to mess with AS until you confirm.
I thought that anti-skate is always set by ear, you don't need no bloody test records, just listen. I am not familiar with the OP's set-up but with my Nottingham Spacedeck/Spacearm you can clearly hear the difference while moving the weight back and forth. It took me fifteen minutes and a few records to find the overall best setting and forget about it. 
The idea that no anti-skating always sounds better is a complete BS.

I think it depends on the rig that you are using.

A very tolerant cartridge (one renowned for excellent tracking) will make it harder for us to judge an optimal A/S setting (apart from clear visual indications that we’ve gone way over the top with A/S).

Personally I would never use a cart without A/S because it will cause asymmetric wear on the stylus which, eventually, will become a far bigger problem for your records (and listening pleasure) than any cartridge mechanical issue.

If you are comfortable with these caveats then it becomes a matter of individual choice.

Regarding Balance there are many possibilities. For example -

- The cartridge can be naturally unbalanced. (Not severely, one would hope)

- The electronics can be unbalanced.

- The room can be unbalanced.

- Your ears can be unbalanced.

Always check the last one first ;^)

All the best,

A simple method for setting anti-skating that I’ve found to work well, at least with cartridges having medium to high compliance (I have no experience with cartridges having low compliance), and which I’ve found to generally require little if any subsequent fine tuning by ear, is as follows:

1)Observe the cartridge from the front while it is in the groove of a rotating record, and positioned somewhere in the middle of the record.

2)Adjust anti-skating until deflection of the cantilever to one side (left or right) becomes barely perceptible, relative to its position when the stylus is lifted off of the record. Note the setting.

3)Adjust anti-skating until deflection of the cantilever to the other side (left or right) becomes barely perceptible, relative to its position when the stylus is lifted off of the record. Note the setting.

4)Set anti-skating to the mid-point between those settings.

5)Verify that no perceptible left or right deflection of the cantilever occurs near the beginning and near the end of the record.

Regards,
-- Al

Skating force varies with groove velocity and offset angle and while there might be no perfect setting, it is possible to find an appropriate setting for your situation, and fine tune by ear.

The Almarg method of obversation is appropriate IMO. Just remember AS force is applied to the arm and you generally want the cantilever to be deflected equally toward the outside or inside.  All of the settings effect all the others. Alignment, VTF, SRA/VTA, azimuth, are are all interrelated.

fleib

Thanks, Fleib. Your post reminds me that I should have mentioned that the procedure I described should be performed during low volume musical passages, having minimal groove excursions.

Regards,
-- Al

Next thing we should discuss is the best way of lowering the arm on the record. So much talk for nothing.
I guess we shouldn't post any longer to this thread, because Inna is bored, but I was rather surprised to read that go4vinyl and Raul suggest the problem of unequal gain in one channel vs the other could be due to azimuth maladjustment.  In fact (this has been said many times too, Inna, so you can stop reading here), azimuth has very little effect on channel balance and adjusting azimuth is not a good way to address channel imbalance.

As to why the OP perceives that AS is affecting channel balance, it could be because badly out of whack AS is inducing distortions that are perceived as more or less output on the affected channel.  Just a guess. Cleaning all mechanical contact areas, as Raul did mention, is a good idea.

I agree with a few others who stated that AS should be adjusted while playing music with the stylus in the groove, not on the run-out or grooveless surface of an LP.  Since skating force is due to stylus friction in the groove, a smooth patch of vinyl does not generate a force that is representative of the problem.  Almarg's method for adjusting AS seems fine; I just don't have the patience or the visual acuity for that.  I am not quite in Stringreen's camp, either. I just set AS to the most minimal value possible, and then I forget about it.
Inna....if you can't hear that no a/s is better, then your hearing is impaired,  your system is not good enough or set up carefully enough.  Harry of VPI doesn't use a/s either.   I have had cartridges for years with no ill effects of not using a/s. These pages exist for those who seek points of view that may require a more open mind with removal from the rear end.

Stringreen said :-

"These pages exist for those who seek points of view that may require a more open mind with removal from the rear end. "


This is a tough case to answer, SG.

I’m sure that some on the Forum would benefit from “removal from the rear end” but it’s not going to happen anytime soon for purely practical reasons.

I’m assuming of course that you refer to the complete removal of the unfortunately named A/S mechanism from the rear end of the tone arm to eliminate another external influence on the tonearm & cartridge?

It should be noted many people do the opposite and deliberately attach materials & objects to their tonearms to “reduce” the resonant behaviour of the arm i.e. dampers.

In some tonearms, the A/S mechanism is secure and does not “rattle” in the way that pulleys and threaded weights might so any benefit that might be obtained from disassembling the A/S itself would be of limited value. I speak as someone who, in a previous life, was quite anal about removing energy drains and sources of extraneous resonance.

HW is also an advocate of twisting tonearm wires to effect A/S. These will also exert an influence from the pivot rather than locally at the cartridge(?) thus giving you back, to some degree at least, the very same problem that Doug Deacon has crusaded against.

Have you checked that you’ve truly “zeroed-out” the effect of the tonearm cable on your rig?


A final point about "no wear being exhibited after years of use". As you know this subject has been formally studied and many cartridges tested to destruction. The one thing they were absolutely certain of is that asymmetric wear on the diamond is a guaranteed direct consequence of either too much or too little anti-skate.

You cannot change the Laws of Physics but you can have a good time trying ;^)

Stringreen,

You're rather insulting to those of us with a different point of view.  Not only that, you don't know what you're talking about.  If you can't hear channel imbalance w/o anti-skate, then you have a linear arm or a hearing problem.

Regards,

To all the anti anti-skaters!
This guy should know more about anti-skating than you do!
http://www.sound-smith.com/do-i-need-anti-skating.html
now, now boys......what I say is that a/s can never be adjusted properly,.. and does harm to the end result than to use it. It produces a force which prevents the stylus from being free to respond to the undulations of the record, and thus closes in the sound. The absence of a/s opens the sound and I certainly can hear it on my system. I wrote what I did to encourage people to listen with and without to determine what’s best for you. Soundsmith proposes using it because he fixes cartridges and it seems right for him. Harry builds turntables and doesn’t use a/s on his tables, but includes the mechanism because of market wishes. I don’t use Harry’s twist method which is another means of using anti-skate. I don’t care if anyone uses it or not...only recommend listening and deciding for yourself. That’s what these pages are for. I can tell you that with my system if I use my Ortofon, Benz, or Dyna cartridges, they all sound better with no a/s....and not only is the sound better, but I never have tracking issues with any of the cartridges...no sibilant S's, no unexpected fuzzy sound in the louder sections... nothing.
...what I say is that a/s can never be adjusted properly...
And therefore any anti-skating setting, including zero, is a compromise.  Which says nothing as to whether zero may be a better compromise or a worse compromise than any other.

As I mentioned earlier, I have no experience with low compliance cartridges.  But I can say that with cartridges having compliances in the higher parts of the spectrum setting anti-skating to zero would result in cantilever deflection toward the outer edge of the record that upon close visual examination is so severe that it would seem to me to be absurd to even try such a setting.

Yogiboy, thanks for the link.  Very informative article, from an unimpeachable source as you implied.  I note, btw, that in Mr. Ledermann's reference in the article to looking at cantilever deflection he limits its usefulness to cartridges having medium to high compliance.  Although he is addressing its usefulness as a check for gross error, rather than with respect to the adjustment procedure I described above.

Regards,
-- Al
 
Dear lewm: Agree, AZ per se ( normal conditions. ) can't change the SPL on one channel, perhaps on " extreme conditions of a very bad AZ set up. Same with AS.
Now, what I was thinking is that in a wrong set up exist an accumulation of " errors " on diferent parameters that even if the SPL is not impaired we can perceive the sound as unbalanced one.

I think that  blueranger can take the " short/path/road " to fix the problem:

- listen in the same analog rig a diferent cartridge looking if exist the same unbalanced quality sound.
Here he can discern if the problem is in the Ortofon Cadenza Bronze or not

- Listen to his CD player looking for that channels unbalanced sound. If persist then is not a cartridge problem or phono stage problem but: line stage/amplifiers or speakers or even some kind of problem in the tonearm.

From here, he has to follow tests on each of those single system chain links.

Now, we can follow give any kind of advise to blueranger but it's not easy for any one of us to say with precission where is the real trouble.


Regards and enjoy the music,
R.


Dear friends: On the whole AS subject I think that no one of use has the " bible " about.

By the physics laws AS always exist in a pivoted tonearm, so we can dissapears it only because we can't detect its " microscopic " influence in what we are listening. Like is the case of SG and some of us. Example, I change to often of cartridges and is a " pain in the ass " the AS set up that is related with all the oother cartridge set up parameters. So I decided for some time forget about but I know is not " right ".

Problem with the AS subject is that we don't know yet ( at least me. ) a precise methodology to set up the " Right " AS because several obstacles: is changing all over the LP surface ( iws not static but dynamic. ), we don't know on each LP recording its diferent recorded velocities over the LP surface and the difference in cartridge stylus shape has influence too on the amount of AS ( in this regard I remember at least one of my tonearms AT where its AS mechanism noted diferent AS position for: sherical, ellipthical and line contact stylus shapes. ).

So, AS set ub is a night mare for say the least.

Today and only for a " mind in calm " I use AS at minimum posible. How knew it's at minimum? I did not.

Cero or at " minimum " is wrong but everythink we make about is wrong. Maybe the real subject could be which kind of AS set up makes the less " damages ".

Regards and enjoy the music,
R.
Someone else mentioned the room. I had a channel imbalance after tweaking everything over and over I still had it.  Last but not least I moved a bookcase a couple inches and that was the ticket. 
Thanks for all your answers in this subject. I will have to get a slim bubble level to check tonearm. I checked platter with round bubble level and it was leveled right. I thinks that might be problem. 

Years ago ('80s) part of my job was checking for stylus wear.  Ever see a tip well worn only on one side?   Think skating might have something to do with that?

The purpose of anti skating is to keep the cart moving assembly centered in the groove, putting relatively even pressure on each groove wall and consequently having appropriate deflections from said groove walls.

If your image is consistently off to one side or the other, perhaps it reflects uneven cantilever/tip centering as a result of incorrect AS applied to a pivoting arm. This is a type of distortion.  The information on the record is not being reproduced with correct amplitude, channel to channel.  Some information will tend to get buried in the mix, and other info. might be more prominent than intended.

Why are heavy trackers more immune to the affects of skating?  The down force (VTF) is great enough to overcome most of the skating force
mis-centering.

If your goal is to reduce torsional forces on the cantilever, then look to arms with no offset.

fleib




fleib is right on about anti-skating! Soundsmith has the same conclusion!
Any tone arm with a headshell that is angled to provide best overhang performance (zenith) creates a substantial skating force - NO EXCEPTIONS. Antiskating IS always therefore required, although it is often applied incorrectly. The force required may seem insignificant to many, but if you were to look at the many thousands of cartridges I have looked at over the past 43 years, you would undnerstand that it is required. The scale of the tone arm does not allow most people to understand that is happening at the scale of the stylus/groove wall interraction. These forces are NOT insignificant.

Almost always, most tables are adjusted incorrectly, and have too much anti-skating, or it is disregarded, and there is none. Sometimes, with some tables, it cannot be turned down enough, OR the range and fine control is terrible.

Usually, most folks use far too much antiskating, as evidenced by the thousands of cartridges I have rebuilt over the last 40+ years ��" THis is by observation of the outer facet edge (right channel) of the diamond to be worn far more than the inner, or left channel.

A properly designed anti-skating device is non-linear, as it should be, as it needs to increase A-S automatically at the inner grooves due to increased stiction.

Frank Schroder and I are of the same opinion about antiskating ��" and that makes MOST records that provide an "anti-skating track" totally in error ��" many are recorded at about 80-90% modulation -OR MORE, or have increasing levels of modulation as the track progresses and expect you to set the A-S force so that there is no distortion at all at any level of modulation (or equal amounts on both channels if the cartridge tracks poorly).

The problem with these tracks is that since the required level of A-S force is a function of the amount of modulation (and of course the VTF), it has you adjust antiskating at far too high a level. This would be OK, if you are listening to music that is constantly recorded at a high level. No music really is. When you adjust for this level, that means that you are very much overcompensated with far too much antiskating as you have adjusted it for where the music does NOT spend most of its time ��" it spends it at about 30-40% modulation levels ��" so adjusting the A-S with these records results in far too much A-S force - too much on the right channel, and far too little on the left.

Since there is no properly recorded track that allows proper setting of A-S (there will be such on our new Soundsmith adjustment record), the method that Frank Schroder crafted through careful reverse engineering works without tools, and without a special record.

If one sets the stylus on a smooth surface of a record (at the end, in-between the run out grooves) ��" the tip of the stylus has a drag on the surface that while not equal to, is "standardized" enough to allow it to be used to adjust the Anti-Skating. This is due to a calculation of “force per unit area” with consideration of the rheology of the material ��" vinyl. Suffice it to say that since it has been reverse engineered and calibrated properly, this method works well. It then becomes an easy matter to set the A-S and observe the movement of the arm. For a given VTF (any amount of VTF) ��" set the A-S so that the arm VERY SLOWLY drifts inwards when placed on the SURFACE (NOT IN A GROOVE) at the end of a record. You will have a moment to do this until the stylus “pops” into the run-out groove.

This works for ANY amount of VTF required, for ANY cartridge. It will set the A-S to EQUAL force per groove wall for 30-40% groove modulation levels, which is the best level for A-S force, as it is a moving target. What one DOES want is anti-skating that is basically correct for where music spends 80-90% of its time.

Peter Ledermann/Soundsmith



Dear Stringreen,

Sorry for misunderstanding you earlier although I did realise that you were also referring to the "source" of the applied A/S force as per Doug Deacon’s frequent eloquence on the subject.

DougDeacon, the principal advocate of the “no-antiskate philosophy” doesn’t appear to be here to speak for himself but what you refer to is the “benefit” of removing an undesirably influential force (i.e. A/S) applied at the “wrong” end of the tonearm such that the cartridge’s suspension is unnecessarily stressed or tensioned by it, and that removal of this force is preferable to the disadvantage of not having skating compensation at all.


This type of “sacrificial” purist approach to LP replay is not new and we see many examples of it in turntable design e.g. designers such as Willie Bauer eschewing more expensive Rega tonearm’s in favour of the cheaper RB250 because it didn’t contain spring-based mechanisms for A/S etc on the grounds that he could hear the negative influence of the springs in dynamically balanced arms. Another example is the adoption of the 3-point fixing by some companies (e.g. Naim) which disregards the “necessity” of alignment flexibility & accuracy in favour of secure fixing on an appropriately equipped tonearm.


Unfortunately, I see this "zero-antiskate" approach as flawed because anti-skate is not the only way that a cartridge’s suspension can be stressed…

One example is that if an LP is drilled off centre (nearly all LPs are), the cart will be forced to ride from side-to-side instead of simply tracing the normal “regular” path of the groove. I would imagine that this sets up forces in the groove which are just as troublesome, in absolute terms, as anti-skate.

It is important to note that cartridges are actually designed to handle these forces.

Under these conditions, if one could “zoom” down to microscopic level and ask the cartridge how it is faring it would probably tell you that there’s not much difference between this and skating force, that it’s "all in a day’s work" for your average phono cartridge.


Second-guessing what DD might say, he would probably argue that LP mis-drilling “forces” are oriented at the “correct” (stylus) end of the tonearm and that the cantilever would be intrinsically less stressed than by A/S.

Not sure I’d agree with that one either because it doesn’t consider inertia. If anything I’d say it’s worse because it is causing periodic de-stabilisation but that’s the reason cartridges have suspensions.


However, variety is the spice of life and if you are happy working without anti-skate then that’s all that matters. It’s an individual choice and we’re not here to press-gang you into accepting conventional methods.

Happy listening ;^)

Stringreen, have you given thought that your take on anti-skate might apply more to uni-pivots than to gimbaled tonearms?
It's been awhile since I adjusted AS, but maybe(and this is done with a gimbaled tonearm) my final result, which was just less than where the sound becomes locked in(in a way-maybe where everything, like channel balance, seems to be correct), has to do a little bit with the "opening of sound" he talks about.  i do remember sleeping on what appeared to be the correct setting(based on channel balance, etc.) and was less enthused about listening to music.  When I put it back(remember these changes to AS were almost imperceptible movements), the magic came back. 
Blueranger, I think you are correct about checking the level of your turntable.  I think that's most likely the problem, when you have a quality arm, yet have to put AS at it's maximum.
Peter Lederman probably has forgotten more about vinyl set-up than I will ever know, but I do have to disagree with him on one small point; the genesis of the skating force begins with the fact that 95% of tonearms are mounted so as to have the stylus overhang the spindle (by, typically ~15mm).  This is done to obtain two points on the surface of the LP where the tracking error can be null, but the trade-off is that (without also introducing headshell offset angle) the cantilever can never be parallel to the groove.  This is proven by the Pythagorean theorem, where the tonearm is side A of a right angle triangle, the radius of the LP from stylus to spindle is side B, and the P2S distance is side C.  Because you start out with a situation where A>C, due to overhang, then the Pythagorean theorem that governs the size relationships of a right-angle triangle can never be met (C-squared = A-squared + B-squared). Headshell offset angle, in conjunction with overhang, allows for two points on the LP surface where the cantilever IS parallel to the groove, but some skating force is present even then, because of headshell offset angle.  Those two null points for tracking error are the only points where ALL the skating force is due to headshell offset angle. Otherwise, it's both overhang and headshell offset that cause skating.

Lewm, Your point is moot. Obviously skating is caused by friction, but why is there skating on a pivoted arm and not on linear?

Skating is caused by both lack of tangency and offset angle, and is still present at null points due to offset.  Why does a pivoting arm with no offset (RS Labs) still have some skating?  Lack of tangency. 

Regards,

Flieb, Thanks for saying exactly the same thing that I said in fewer words and without the physics lesson.  If my point(s) were moot, your points are moot-er.  I realize that an experienced person such as yourself would have the facts well in hand. My post of 4-13 was aimed only at those who might not.

The RS-A1, and any other tonearm designed for "underhang" and lacking any headshell offset, WILL achieve zero skating force at the one (not two) points across the LP surface where it also achieves tangency. (Because the stylus underhangs the pivot, there can only be one point on the arc where tangency to the groove is achieved. However, at that one point, there is no headshell offset to generate skating force.)  I know you know this, Fleib.

Why is there no skating force on a linear tracker? The whole idea, as you know, is that there is ALWAYS tangency to the groove, and there is never headshell offset angle. Thus, no skating force. However, in practice, if there is even a minute error in set-up; if the stylus is not exactly on the imaginary line that describes the radius of the LP, then there will always be that tiny amount of skating force.  Also, if there is any play in the bearing such that the stylus can describe even microscopic arcs as it travels across the LP, this too will generate a small skating force.  The Rabco/Goldmund linear tracker actually depended on its loose bearing to periodically activate a servo motor that dragged the assembly across the LP.  That was not a good design, IMO. I know you know this, Fleib.

Lewm, you're welcome, and thank you for admitting, I am mooter than thou.

You're right about most linear arms lack of tangency. Often the pivot is playing catch-up, but to what degree is there alignment error and how does this compare to pivoted arms? 

Regards,

I suspect that there is always a tiny amount of tracking error and a tiny amount of skating force and that both are so small in magnitude and so relatively constant across the LP surface that these two qualities (small and constant, compared to a pivoted tonearm) account for why we hear linear trackers as sounding different from pivoted tonearms, although not perfect.
Lewn, while theory is a good place to start experiments, you still have to try it out in real life.  While it's possible that Peter Lederman was predisposed to look for that asymmetrical stylus wear to prove what he believed, it's also possible(and maybe more probable) that that's what he actually found.

BlueRanger,

We appear to have hijacked your thread with theorisations about antiskate (myself also guilty as charged). Getting back on topic I think you may be on the right track by checking levels.

Suggest checking :

  1. The platter using 2 small opposing spirit levels in 2 axes.

  2. The armboard (over its whole surface and in more than one axis). If the armboard is cantilevered/assembled there may be interference between armboard and chassis or the armboard itself may be distorted depending on what material has been used.

  3. If possible, the headshell or tonearm level.

The idea is that 1-3 should be always be “square” with each other in all axes.

If you can check the chassis itself that might be useful in case the main bearing/chassis itself was distorted or misaligned.

I’ve heard of turntables being shipped with heavy platter semi-assembled but decoupled suffering a warped main bearing in transit. Choice of materials could even lead to the chassis itself being warped. Either way a chassis error would undoubtedly reveal itself eventually.

 For the purpose I can recommend these :

 http://www.russandrews.com/bubble-level-twin-pack-50219990000/

 Let us know how you get on.

All the best,

I think all this discussion of anti-skate is interesting.   My object for deciding to us a/s or not is that when listening to a record, there is an ease in the sound that changes to something else when I apply a/s.  The object of all of this is to get sound that is closest to a live performance (I know that I can get it close but somehow..) Anyway...s/f is applied to counteract the inward moving force of the arm.  What we forget is that the arm is succumbing to that force by moving in that direction anyway.  I am a musician, not a physicist, but the thing simply sounds better on MY system with any cartridge I have installed with no a/s.  If that damages my stylus so be it....I don't have a balloon raise my car off the ground to safeguard my tires...just the cost of doing business.

Stringreen, you make a valid point. The reason some prefer an underhung straight tracker is because of reduction of torsional forces on the cantilever. This is despite a large increase in alignment error.

A case could be made for either approach.

Regards,

I am curious about a long length, underhung tonearm.  None seem to exist, yet it would appear to be an interesting option, curing one of the problems with the available underhung tonearms (they tend to be short in length which increases the tracking angle error on both sides of the single null point) and at the same time avoiding the necessity for headshell offset.  Something like 12 inches with no headshell offset angle.  Seems to me that Nottingham made a 12-inch tonearm with no headshell offset, but it was not "meant" for under hanging.  One could try that though.  Probably there is nothing like that on the market, because of the fact that it would require quite a lot of real estate back at the pivot point. It might require a custom-made plinth/arm board.
mmakshak, In your post of 4-15, I am not sure what you are referring to.  I took no issue with anything PL said about stylus wear.  I only noted that his brief reference to headshell offset angle as being THE cause of skating force is not quite accurate.  Otherwise, I would never dare to doubt anything he says about cartridges, especially one he personally has examined with his own eyes.  

By the way, it's Lew M (or Lewm), not Lew N.  You're not the only one who misreads the "M".  Thanks.