Feel Silly Asking This Question Alignment Parameters

Thanks for making me think about that statement.

@lewm - Notifications when you're mentioned in the forums is I believe controlled by a setting in your AG profile. For the record (no pun intended) the only issue I raised from your earlier post was the claim that "AS is constant in magnitude". I'm also in agreement that the use of AS is an approximation and not an exact science.

One of my tonearms is an OL arm as well. I solely use a generated arc protractor.

For conical and elliptical stylii I always align with Stevenson, as IGD can be an issue with these stylus profiles. For radical cut stylii I try both Stevenson and Loefgren A and judge by ear, but sometimes end up back at Stevenson.

When setting up cartridges for other folks, if they are primarily a classical listener I will weight the decision towards Stevenson.

Good luck, and dont overthink it. All alignments are compromizes.

So I just watched the two videos that bill_k referenced, and I don't perceive any conflict between what Peter says and what I wrote, except for the fact I was technically incorrect to have written that the AS force is constant.  Upon further thought, I see now that, at least for the conventional string and weight type of AS devices, the force pulling the tonearm would increase as the tonearm approaches the label, because the angle between the string and the arm wand is approaching 90 degrees, at which point all of the mass of the weight (force, F) would be pulling on the arm wand in the desired direction.

FWIW, I wasn’t notified of your response.

The gist of my response to PL is that yes, AS devices might increase the AS force as the stylus approaches innermost grooves, but no, in general AS devices don’t follow the skating force in magnitude. Or AS does not successfully cancel the skating force, to put it another way. I don’t think PL would make that claim.

@lewm - Just happened to catch your post, but for future posts directed to another user you should use @username so they'd be notified. I had to do some searching to find where I sourced that quote from Peter but got it. It's on the following page in the "There's More..." section. https://www.sound-smith.com/faq/how-do-i-adjust-anti-skating-my-cartridge He covers many of the important aspects of AS there.

bill_k, Can you direct me to Peter Ledermann’s quote as follows: "With all due respect you [referring to me, Lew] stated that "AS is constant in magnitude" which is not true. As Peter Ledermann confirms: "A properly designed anti-skating is non-linear, as it should of course increase A-S automatically as the cartridge approaches the inner grooves."

This stimulated me in several directions. First, it may have been flippant of me to say that AS is constant in magnitude across the LP surface; I should have thought about it in greater detail, but if you consider an old-fashioned string and weight AS device, what would change the magnitude of AS force as the tonearm swings in toward the platter is the angle of the pull of the string/weight on the arm wand, assuming that friction of the string on the guide is unchanging. That changing angle would indeed probably change the magnitude of AS, but such a change would be linear with a slope related to the changing angle of the pull force. That still does not mimic the ups and downs of the skating force. The AS force exerted by a magnetic device would also vary but also would not closely mimic the changes in skating force that occur in the course of playing an LP using a pivoted overhung tonearm. Finally, I wish I knew what tonearm Peter was thinking of when he wrote that passage. Finally, finally, is it indeed true that the max skating force occurs at the innermost grooves? Gotta think more about that one, but off the top of my head, the skating force would be related to the headshell offset angle at the innermost null point (a minimum) and then rise as the stylus approaches the runout grooves. Before the tonearm reaches the innermost null point, the skating force is created by headshell offset angle PLUS TAE. At the outer null point, it is again caused only by headshell offset. And at the outer grooves, again we have both TAE and offset. There is just no way to design an AS device to follow those variations, and this does not even take into account groove tortuosity as another ever changing source of a skating force.

@cundare2

NO ONE who is serious about vinyl reproduction should try to fool themselves into thinking that they can accurately and precisely align a commercially manufactured cartridge without WAM on their side.

I could not agree more. I went all in with analysis, tools and support from JR for a new TT and Cart (maybe end game). At this level you really are wasting money without WAM.

 

@thom_at_galibier_design 

I forgot to mention, the cure for improper zenith or any other stylus orientation problem is a new stylus or cartridge. IMHO every cartridge should be examined before it is mounted for the first time. If the stylus is not mounted correctly it should be covered under warranty and usually is without argument. Under optimal circumstances the examination should be done before the cartridge leaves the retailer. A file of the pictures should accompany the cartridge. Most individuals are not going to spend $1500 on a usb microscope and proper staging. 

@thom_at_galibier_design Welcome Thom.

I am a big fan of Frank Schroeder. I currently run a CB. The method of setting AS recommended by Frank and Peter is useful for people who have no better way. The problem is defining what a "slowly drift" means. One person's slow drift may not be another's. From a tracking and record wear perspective too little AS is just as bad as too much. The determinants of the skating force are VTF, contact patch size, groove velocity and modulation density. The skating force increases towards the center of the record because the modulation density increases. For any one particular set up VTF and Contact Patch are constants. With a reasonably compliant cartridge like a Lyra or Van den Hul you can determine the correct AS force by careful observation of lateral cantilever deflect as the stylus settles into the groove at the midpoint of the record. Bright light and 10X loops help. The cantilever should not move laterally from its resting position. This corresponds to a Wallyskater reading of 12 % for really acute styluses like the replicant 100, Gyger S, Soundsmith MR and Jico SAS. More conservative line contact styluses, like Lyra and My Sonic Lab use, correspond to a WallySkater reading of 11%. Even though groove velocities can vary from one record to another, there is little difference in the AS required from one record to another. This problem exists for any method of setting AS. 

Having gone through the above process many times I have no problem trusting the WallySkater. It is a rapid and easy way to find a reasonable, average AS setting and definitely more accurate than a "slow drift" towards the label in the run out position. I know exactly what 11% means. 

+100 re:WAM Engineering ("Wallytools"). J. R. Boisclair is one of the most knowledgable engineers in the country, maybe in the world, when it comes to optimizing the performance of cartridges and tonearms. His site & online channels are packed with tutorials, reference information, research results, etc. Buying a full set of Wallytools isn't cheap, but it's a one-time investment and in my own first-hand experience, JR's microscopic analysis service & toolset made a more dramatic improvement in my vinyl reproduction than did upgrading to cables that cost far more -- and I experienced consistent results with MM & MC cartridges ranging from $700 to $2800. Before making a decision based on well-intentioned, often well-informed, but outsider-looking-in advice from fellow members, you owe it to yourself to at least browse through WAM's online resources (and Michael Fremer's excellent WAM overviews in Stereophile). In my opinion, NO ONE who is serious about vinyl reproduction should try to fool themselves into thinking that they can accurately and precisely align a commercially manufactured cartridge without WAM on their side. Even the best "standard" protractors only get you partway there.

@lewm - With all due respect you stated that "AS is constant in magnitude" which is not true. As Peter Ledermann confirms: "A properly designed anti-skating is non-linear, as it should of course increase A-S automatically as the cartridge approaches the inner grooves."

When I recommend a procedure or tool to a customer, I try to get a read on their aptitude and willingness to learn. Needless to say, mechanical and cognitive skills span quite a broad range and with them, so do my recommendations.

If someone is willing to recognize how alignments are established (and the reason I published that blog post linked to, above), then we have vanquished yet another demon. I look at that as a good thing.

As far as anti-skate is concerned, it is "accidentally correct" at a few points along the stylus’ path, and of course, if you’ve set any anti-skating force at all, it’s wrong at the null points ;-)

I endorse the method espoused by both Frank Schröder and Peter Lederman of Soundsmith (click here for Peter's comments).

Don’t get too cute with anti-skate. AJ van Den Hul once told me that the vast majority of cartridges he receives for inspection show signs of vastly too much anti skate (wear on the outer / lead-in groove side of the stylus).

When you understand that anti-skate is is the vector sum of the forces which in turn vary with groove friction, you’ll realize why any attempt at anything more than a minimal setting is asking for trouble.

Groove friction in turn varies. It is a function of the cleanliness and condition of both the stylus and record, the shape and polish of the diamond, and the signal level encoded in the grooves.

In other words, what works for one record at 87mm from the record spindle may be too little or too much force for another record.

Wally M was a charming, quirky fellow and he has done some amazing work for the vinyl community, but his one product which I strongly disagree with is his Wally-Skater. I did a favor for him at one show, and he offered me any Wally-tool as an expression of gratitude. Thinking that I was missing something, I chose a Wally-Skater.

Read Peter Lederman’s comments on the topic and focus on getting your zenith correct. You may well have been misdiagnosing poor zenith as incorrect anti-skate.

... Thom

There are those that make that argument @lewm. You are either leaning on one wall or the other. My goal is to minimize that as much as is feasible, even it out. An arm that is not offset is ideal as long as it stays right on the tangent. 

I don't think it follows from "there is no right setting" that you may as well not use AS at all. And I apologize for coming on perhaps too strongly.  I use AS on my overhung tonearms, of course, and I try for a minimum amount that eliminates distortion in the R channel that I can hear with zero AS. So maybe by shooting for that entirely subjective endpoint I end up using a tiny bit more AS with those exotic stylus shapes you mention. I would need the Wallyskater to determine that.

@lewm You are right Lew. The question is what is the best average over the entire play area.  The amount of AS required increases with the size of the contact patch at any given VTF.  Studying cantilever angles is an extremely fastidious way of going about finding the right setting. Some would argue there is no right setting. Then I would argue why use AS at all. Most of us with 1/2 a brain are going to call that a bad idea. So since everyone with 1/2 a brain agrees that we should be using some form of AS, and we know that the skating force is variable, not a constant, how do you go about figuring the best average and a way to dial it in consistently with as little effort as possible. IMHO the WallySkater is the best way. If you want to look at cantilever angles to dial things in further, why not. I do this every time I use a new to me stylus profile. I have found that styluses like the Soundsmith MR, the replicant 100 and the Gyger S do best at 12% of VTF. Lyra's line contact and MSL's line contact take 11%. It will be interesting to see what the V15 MR with it's extremely high compliance and low VTF will take. I will have the Jico stylus tomorrow.

Mijo, I don't know whether you agree with me or not, but what I wrote is that AS can be exactly equal in magnitude (and hopefully opposite in direction) to the skating force at only two points on the LP surface.  It seems to me this is true for any stylus shape, and length tonearm, etc.  Because AS is constant in magnitude and direction while the skating force describes a kind of eccentric parabola if you plot its magnitude with respect to the distance between the innermost and outermost grooves, and this is disregarding the vicissitudes of the skating force that are due to the program material.  A straight line (the graph for AS) will intersect the skating force parabola at two points, unless AS is incorrectly set lower than the skating force minimum or higher than the skating force maximum. And anyway, do you REALLY think there is much difference between 9, 10, 11, or 12% of the skating force?

There’s a bit too much to address individually on this topic. The last thread that was loosely related to this this subject hit a few days after I put this blog post out.

TL;DR #1: There numerous excellent geometries to choose from. Dispense with your confirmation bias about Löfgren A/B, Stevenson, Uni-DIN, etc. And faithfully follow your favorite.

TL;DR #2: I strongly suspect the "controlled" experiments many have reported on this thread are heavily skewed by (1) not getting the zenith right and (2) varying it slightly with each setup - invalidating any comparison. Take a look at the distortion and tracking angle curves in the above post, when the zenith is off. I have not compared zenith errors across all alignments, but know this: zenith is the new azimuth, and it’s much trickier to get right than azimuth is. Aligning zenith using the cantilever is a much more flawed method than setting azimuth with a horizontal headshell and calling it "good".

I say this with humility. As @lewm commented above, I would hope that we all look back at our work product from 5 years ago and view it with disdain ... as far as how much progress we’ve made in our journey.

... Thom @ Galibier

@wrm57, @lewm The best way to see this is with a naked cantilever. The AS setting depends on the type of stylus used. For 9" arms the range is 9-11%. 9% for spherical, 10% for elliptical and 11% for line contact. I push it to 12% with really aggressive styluses like the Gyger S,  Replicant 100 and the Soundsmith MR. When lowered in the middle of a 33.3 RPM record the cantilever should remain perfectly straight. It's horizontal angulation should not change. It it leans outwards towards the right channel you have too little AS. If it leans inwards towards the left channel you have too much AS. The WallySkater settings get you right there without a trial and error nuisance. It also verifies that the bearings and AS device are functioning correctly. I have seen several arms with significant defects. I have also put the stylus down all along the radius of a record and the cantilever's angle does not change notably. When set at the beginning of the record you will see that the cantilever starts leaning towards the right channel just before the run out area proving that the skating force INCREASES towards the end of the record. Setting in the middle gives you a good average. The WallySkator should be adjusted so that the stylus floats over the center of the record. The Lyras,  Clearaudios and Van den Huls are great cartridges to see this. I use 20X loops and very bright lights to aid the process. Unfortunately, cartridges that extend over their cantilever make this difficult to see as will very low compliance cartridges. 

On my arms it takes more than I expect to hit the numbers, and I typically back it off a touch.

At best, any AS setting can be correct (exactly equal in magnitude to the skating force) at only two points on the LP surface. There is a fairly broad range of settings that will satisfy that requirement, 11% of VTF being one of them. I’d be curious to borrow a Wally just to find out how close I get to 11% by simply setting AS to a minimal value above zero .

@lewm : Yes, WallySkator is just for anti-skate. It enables an easy setting to a requisite percentage of VTF, which JR, or perhaps Wally before him, established to be 11% for 9-inch arms, 9% for 12-inch. It does some other things, too, like measure stiction, but AS is its main use.

Why must I have the Wallyskater, if I have both a Smartractor and a Feickert protractor? To set AS? Or what?

This sidebar about mounting distance is irrelevant. SOTA built a custom armboard so the suspension will balance properly and drilled that 222 mm as per factory specs. 

There are three parameters involved: spindle to Pivot distance, pivot to stylus distance, and offset angle of the cartridge. Once two are set the only thing that can be changed is the third. Often the spindle to Pivot and the offset angle are set so that leaves only the pivot to stylus that can be adjusted. I really like the feickert alignment tool. It is pretty much Universal and has calibration marks for the various schemes.

+3 for the WallySkator

@mijostyn : agreed on the WallySkator. A must-have device.

@wrm57 I have the same old eyes you have and as you found out the SmarTractor is a really nifty device. Many people have a hard time getting over the price, but for any vinyl head who is the least bit fastidious it is well worth every cent. I can say the same about the WallySkator. If someone tells me I set the VTF to 2 grams and antiskating at 11% I know exactly what that means. Every other way of trying to describe antiskating is virtually meaningless. 

FWIW, I just now cross-checked the SmartTractor on a cartridge I recently installed with a WallyTractor and the Lofgren B alignments were identical. No change needed. This is extremely enheartening, given the SmartTractor’s superior ease of use. What a nifty piece of engineering. @mijostyn you were so right!

@rauliruegas : Good advice, for sure, to get a universal alignment protractor if you’ll be changing out arms. Just moments ago, in fact, I took delivery of a new SmartTractor. We’ll see how it goes. I’ve always had a preference for dedicated arc protractors, dating back to my first WallyTractor in 2000, and have them for all my arms. But the eyes are not what they were and won’t be getting better. I think the one-point process should be easier.

BTW, Wally preceded Yip at MintLP in bringing dedicated arcs to market, if I’m not mistaken--at least in my awareness. Mints are excellent and missed. JR now offers the generously-named Universal WallyTractor, which has many curves but not all, although he will still do a dedicated protractor at a very high price. I’ve never used or even seen a Feikert but it has a big following.

Dear @lewm @wrm57 : MINT LP disapeaed of the market and was one of the first protractor with dedicated turntable/arm, specific . Was really inexpensive.

The dedicated, one only, alignment hasd a way high limtations for the owner and for the cartridge against universal pro-tractors as the Feickert protractor.

If I will live for ever with that tonearm/TT alignment maybe no problem ( just maybe ) but it does not gives any single advantage over the universal protractors that gaves us to achieve the best quality level performance for any cartridges and tonearms combinations and or different kind of aligments. Ar the end we have try that the cartridge can shows at its best and a dedicated protractor can’s do it, probably at random but who knows.

 

Newcomers must know that could be a big mistage to get married with that kind of protractors and that the best " road " is a Universal alignment protractors. In the other side the OP posted that he wanted to optimize about and maybe he does not achieve it.

R.

@lewm : Well said.

I agree with all you say above, but I just wanted to point out that increasing (what I thought was EL but my in fact be P2S) from 222mm to 225mm has little effect on effective mass, which of course has nothing to do with alignment per se. If we are actually talking about P2S, then the net effect on effective mass of the commensurate increase in EL would be even less than 2%.  But for EL, if effective mass was 20g at 222mm, it would be ~20.4g at 225mm. (This is very inexact, just comparing the square of the two numbers, which is directly proportional to effective mass.) 

Looking back on my nearly 50 years in this hobby, I would unashamedly say that there are some things I did wrong for 40 of those years, some other things that I did wrong for 30 years, and some more unknown things that I am doing wrong even now.  (Not speaking only of tonearm alignment.) For the uninitiated or newbies, they should know it's a marathon, not a sprint to get to audio Nirvana.  But such is our capacity for self delusion that one can enjoy the hobby from the get-go, just keep an open mind and hope to get better at it.

Dover, I’m not quite sure what the argument is really about but my calculations suggest that a change in EL from 222mm to 225mm would increase effective mass by only about 2%.

@lewm 

The OP wants to use an ARC protractor.

As I pointed out earlier, changing the effective length means a different ARC protractor will be required. This is likely lost on many readers.

Unfortunately for many readers who struggle to understand how to set up a TT properly, arbitrarily changing the pivot to stylus distance outside of the manufacturers specifications could lead to disaster in terms of reasonably accurate set up.

You might be quite comfortable with this because you have many years of experience setting up TT's. Unfortunately most don't.

The whole purpose of the OP's question was to address concerns that he had on set up. The word and numbers salads tossed up in this thread - encouraging others to ignore manufacturers guidelines - is a recipe for disaster.

Whilst you might be happy with this, because you enjoy intellectual debate, the reality is, for newbies, confusing them often leads to frustration and disappointment.

Consequently we lose another turntable enthusiast.

Why do we care about folk losing enthusiasm for turntables - well, in a dwindling market, prices rise, the market shrinks further and eventually innovation declines and the market dies.

Have a look at the declining numbers on this forum.

Therefore as you and I and some others on this thread have over 30 years of experience in setting up turntables - it is incumbent on us to help folk with their turntable set up advice by keeping advice simple, accurate, and explain in a way that is easily understood.

 

 

Dear @neonknight  : According the OL information you can make the alignment with that 9.5"  El and this is what you can get and could be the best orthodox alignment shot:

 

https://www.vinylengine.com/tonearm_alignment_calculator_pro.php?arm1=Arm+1&l1=el&a1lv=241.3&a1=la&oh1v=&oa1v=&arm2=Lofgren+A&l2=el&a2lv=241.3&a2=la&oh2v=&oa2v=&arm3=Lofgren+B&l3=el&a3lv=241.3&a3=lb&oh3v=&oa3v=&arm4=Stevenson&l4=el&a4lv=241.3&a4=st&oh4v=&oa4v=&rs=12&rsv=&og=iec1&ogv=&ig=iec&igv=&cal=y&submit=calculate

 

R.

 

 

@dover : It's curious/negative that you took from my posts only what ssome way or the other you can use as a weapon.:

Iposted this information that came from VE but maybe you don't read it or let pass on purpose:

 

" 

 " This document is reproduced here by kind agreement of Mark Baker at Origin Live. "

 

" Rega arms and Origin Live arms require mounting dimensions such that the centre of the platter to the centre of arm hole is approx 223mm plus or minus 2mm tolerance and the hole diameter for the arm is 24mm to 25mm. "  

So that's not my information, I only pasted and used.

 

R.

Dover, I’m not quite sure what the argument is really about but my calculations suggest that a change in EL from 222mm to 225mm would increase effective mass by only about 2%.

" Apparently you think its fine to set up tonearms with an accuracy of +-0.3mm "

You did it not me,so don't put words in my mouth.

Actually you suggested mounting the arm 3mm out of manufacturers specs.

Here is your actual post.

 

rauliruegas

12,992 posts

08-27-2024 at 06:03am 

@dover : No it’s not wrong because OL says a margin of +,- 2mm. In the other side we can change those numbers with out any negative consequence because 225 means longer EL and les distortion.

The manufacturers specs are 222mm - you are suggesting mounting it at 225mm.

That would mean pushing the cartridge out further, significantly increasing the effective mass and inertia of the tonearm beyond what the designer intended.

It's no wonder you have suggested your 1980's CD player is more accurate than your turntable system.

Given that you have been trying to build your own tonearm for the past many years, perhaps you could now focus on a design with an effective length of 48 inches - according to your theory that would sound fantastic - even lower distortion. Pity the poor cartridge though, trying to cope with such vast effective mass whilst navigating  eccentric records.

 

@lewm you know I meant the wavelength of the tracing, obviously the wavelength in air does not change.

@dover  : No, that was finger error.

Even that the calculations for the P2S 222mm shows at that firstlink I posted and the EL calculations shows 239.3 for that P2S. Numbers says that's the correct EL not 239mm., numbers are numbers/mathematics.

 

OLsays in his site:  " Centre of mounting hole to centre of platter should be 222mm (plus or minus 1mm tolerance). "

It's not talking of overhang.

Now, if the P2S distance change to 221mm or 223mm over calculations at the same time changes the overhang and offset angle and the main target for any tonearm owner is to make the tonearm/cartridge/TT alignment with Accuracy and this is what I'm talking about.

Anyway, that 239mm or 9.5" stated by OL can't be achieved with the OL information.

So other that my finger error I think I'm not wrong.

Maybe what created some kind of confusion in my posts was that my " error "I wasthinking that the OPwantsit 17.5mm as overhang.

 

" Apparently you think its fine to set up tonearms with an accuracy of +-0.3mm "

 

You did it not me,so don't put words in my mouth.

 

R.

 

 

 

 

Dear @mijostyn  : That's not the issue. Again starting ( no matters what ) the second null point the cartridge tracking task goes harder to tracing as at the begening/medium distances in the LP grooved surface and for that reason Löfgren choosed that in the last third part of any LP the tracking distortion gone lower and that is why he named to the A solution the Optimal Optimization that's a better alignment that his side line solution B.

 

@lewm   " to the point where the stylus has difficulty tracing the groove accurately. "

Something like that, thank's.

 

R.

Who is way wrong with the numbers is not only you but OL too because 222 + 17.53 is not 239 or 9.5". One of my options that I posted puts the best number nearer to that 239 with a difference of only 0.1mm instead 0.3mm.

Anyway, numbers just do not coincide.

Neither I nor Origin Live mentions 17.53

Please read my posts more carefully as I do not appreciate being misquoted.

Apparently you think its fine to set up tonearms with an accuracy of +-0.3mm despite and wrong offset angles despite claiming in your other posts that unless the phono stage used is accurate to +-0.01db over the audible frequency that the phono stage is not up to par.

I think you should rethink your priorities in how to get the best out of an analogue system.

 

No it’s not wrong because OL says a margin of +,- 2mm. In the other side we can change those numbers with out any negative consequence because 225 means longer EL and les distortion.

This is poor advice.

The OP expressed the desire to use an Arc Protractor.

Anyone who professes to be an expert in tonearm set up would know that an arc protractor is designed for a given mounting distance and you’re not supposed to use an arc protractor designed for a given mounting distance with another mounting distance.

If you are going to use an arc protractor, the mounting distance must be absolutely spot on.

 

I am struggling with ..."any given frequency has a shorter wavelength as the groove speed declines,...."  That is from Mijo's post but he was only reiterating a quote from Raul.  Frequency and wave length are inversely and constantly related, regardless of groove speed.  For example, a 1000Hz tone always has a wave length in air of 0.32 meters. And the declining groove speed on an LP, as the stylus approaches the label, is presumably accounted for in the recording process.  I am sure the text is trying to tell us something, but what? I think it's semantics. I think it means there is less groove length per second available to encode a given frequency to the point where the stylus has difficulty tracing the groove accurately. And this does not even take into account TAE.

Come on @rauliruegas you know darn well that I have read everything. Yes, it is true that any given frequency has a shorter wavelength as the groove speed declines, but the situation does not get serious until you are inside of 65 mm. I would guess that only 5% of the records I have go inside of 65 mm. Many do not get inside of 90mm where Lofgren B shines. If you really want low distortion at the last 10% of the record that hardly anyone uses go with UNI P2S. :-)

Dear @mijostyn  :  It's not that I prefer pivoted against LT only that today for me is the best option, that's all.

 

Btw, it's useless to follow the dialogue with you about Löfgren A and B because I think your never read before the over 150 pages of the 1938  Löfgren papers where you can learn which was his main target no matters if the grooves goes up to the label or not, next again part of what I posted about:

 

" Löfgren developed an optimisation method which involved applying the minimax principle (as used by Wilson) to the WTE. The maximum level of the distortion is then represented by the slope of the tracking error graph rather than by the level of the tracking error. This method results in less tracking error at the inner grooves where the wavelengths are shorter. The introduction of this inverse radius weighting complicates the analytical solution, and Löfgren uses an approximation method which relies on the error angle being small. This is a reasonable mathematical approach, and incurs very little error. An interesting feature of the optimisation method is that the null radii will later be shown to be the same as those provided by the later authors. The optimum solution from Löfgren provides for an offset angle and overhang which minimises and equalises the three resulting WTE peaks across the record playing surface. "

The B solution was only a sifde line and not his main target but to understand what I said before about the LP label you need to understand in deep Lofgren A in the WP.

 

Btw, the comment from that expert I posted came from 2010 .

 

No matters where the LP label is, just after the second null point ( inner ) the cartridge task is way more complicated and where the levels of distortions goes up and up till the last inner groove. The optimization WTE in Lófgren A permits lower distortion level where it matters the more. Take it or leave it but these is the main target/issue by Löfgren and he stated in those WP.

 

R.

@dover : "

Origin live Agile ( standard 9.5" arm 239mm ) has a recommended pivot to spindle distance 222mm.

Overhang for Baerwald A is 17.3mm "

 

I’m not wrong because I only gave neonknigth different alignment choices for his tonearm.

Who is way wrong with the numbers is not only you but OL too because 222 + 17.53 is not 239 or 9.5". One of my options that I posted puts the best number nearer to that 239 with a difference of only 0.1mm instead 0.3mm.

Anyway, numbers just do not coincide.

 

R.

@dover : No it’s not wrong because OL says a margin of +,- 2mm. In the other side we can change those numbers with out any negative consequence because 225 means longer EL and les distortion.

 

I posted the link with 222mm Löfgren A. I think you not read it not even the link of OL protractor I posted.

 

 

R.

@dover My apologies I missed your original post. Yes manual states 222mm and I do have the single point supplied alignment gauge. My preference is working with an arc protractor and wilL purchase one shortly. Thanks for the response.