Uni-Protractor Set tonearm alignment

Dertonarm, I for one would like to know what the Dennessen is based on. Enlighten us if you know.

Dear Dertonarm: The original FR manufacturer numbers are totally wrong, these people IMHO wants only that the numbers appears in easy way for the customers but with out real care on the accuracy to Stevenson IEC solution and with no care on distortions. The original numbers: 245/230/15 and 21.5° don't match with any known geometry solution it does not matters changes in the input data for those calculations, makes no sense.

The " new " parameters for Stevenson IEC are better and the ones for Löfgren A/Baerwald ( that I posted to Halcro. ) are exactly the ones for this solution.

It is not true that the parameters you give Halcro that match Stevenson has lower distortions and this any one can confirm through VE calculations where we can see and " read " the diagrams/chart/graphics with the result on Stevenson/Baerwald/Löfgren curves.

Stevenson only gives a lower distortion at the inner grooves with a higher distortions all over the remaining 90% of vthe LP recorded area.
IMHO you have a misunderstood in this subject, please check not only the Dennes papers but the graphics on the curves through VE calculations.

Btw, Halcro obviously that a re-set in VTF is in order. I only want to insist that the reset on VTA/SRA and Azymuth is not only a must but critical to any comparison: accuracy in this set up parameters is a must ( desired. ) to have.

Regards and enjoy the music,
Raul.

Raul,
When I changed to the 231.5mm spindle to pivot dimension and 14.5mm overhang, I changed the off-set angle to compensate correctly at the null points.

Dear all, just out of curiosity - does anyone know, what calculation is used with the Dennesen Soundtraktor ?
Cheers,
D.

Dear all, the UNI-Protractor does feature on it's main frame laser engraved the inner radii for both IEC and DIN standard in a way that if you place it on the record, you can immediately read-out what is the inner groove limit of the record.
Thus giving you a secure basis to choose alignments taking into consideration the groove limit of the majority of your records.
Cheers,
D.

Dear Raul,
We are all thankful for this thread
& your precious contribution in the subject.

Dear Halcro, the change to 231.5 mm mounting distance (and thus effective length, offset(slightly) and overhang does indeed result is a lower overall distortion level for about 74% of the grooved area compared to the "original" specification in the FR-60 manual/paper template of the FR-64s.
Distortion levels at the start of a 12" record are far less obvious (read: audible) and far less dangerous then they are towards the inner label.
Why so?
Because the difference in radius of the inner groove wall towards the outer groove wall increases with decreasing record radius.
Not a great situation for the stereo stylus.
This too is one of the reasons, why "average distortion" and "maximum distortion" figures for a given tonearm alignment calculation only give half the story.
Where are the maximum distortions? At the start of a record (usually with my calculations) or at the end of the grooved area (Löfgren A/Baerwald and Löfgren B).
How is the "average" determined ? By a narrow but very high maxima and a long area with low distortions ? Or by a rather long area with mid distortion level but no real high peak ?
IMHO (god - I really begin to love this phrase ... ) average and maximum distortion figures may be fine and all for some, but they do not really get to the core.
So why did you hear immediately an improvement in sound with "my" recommendation changing the FR-64s alignment?
First - you had less skating force (remember me saying that there might be additional breakdown torque with an added offset?).
Second - the not linear distortion level was less by 30% for more than 70% of the record.
Third - the FR-64s' "inner" geometry was finally matched by that alignment.

Some may think it is all just effective length and the resulting and depending parameters - offset and overhang.
IMHO ...;-) .... - that is not the complete entire model and doesn't tell all the story.
BTW - all UNI-Protractors of the 1st production run do get collected for ship off tomorrow and thursday.
Cheers,
D.

Btw, the maximum distortion on Baerwald is 0.598 with an average one 0.390. These figures are lower than the Stevenson ones you are using by around 23% lower.

Regards and enjoy the music,
raul.

Halcro: you said that you was using 230mm pivot to spindle on Baerwald and this is for a 246.736mm on EL that is diffferent from the 245mm manufacturer number and that gives you different overhang and offset angle.

Anyway if we/you want to compare the same 246.324mm EL as with Stevenson ( at 231.5 pivot to spindle. ) then on Baerwald the overhang is 16.76mm with an offset angle 22.29°.

Regards and enjoy the music,
raul.

Halcro, of course that you have to re-set the VTA/SRA and Azymuth for the new geometry set up. Sorry to take your time but things could be that you could like the Löfgren/Baerwald geometry. We don't know yet.

regards and enjoy the music,
Raul.

Dear Halcro: The FR64 manufacturer numbers are for Stevenson IEC geometry set up ( and Mr. Ikeda don't take the exact Stevenson parameters but only an aproximation: he put for example 15mm on overhang instead the calculated number: 14.91mm. he did the same for the offset angle and pivot to spindle distance. ).

With the FR 245mm efective length and 230.09 pivot to spindle distance the Stevenson IEC calculations gives you: 0.728 on maximum distortion with 0.477 as average distortion.

If you change the pivot to spindle distance to 231.5 then the new Stevenson IEC calculations gives you: 246.324mm EL with 14.824 on overhang and maximum distortion is 0.724 an average one is 0.474.
Changing only the overhang to 14.5mm gives you a maximum distortion 0.724 with an average of 0.475.

Now for each one of this calculations the offset angle is different. The FR manufacturer offset number is 21.5° that's is greater than the 21.149° and 21.269° on those calculations.
So, if you don't change the 21.5° original/manufacturer cartridge offset angle then what you have is higher distortion levels that the ones here calculations showed.

If all this is true IMHO that you like better a higher distortions set up is not at all something weird, all the time some of us like some kind of higher distortions than lower ones.

I don't have mounted my FR right now ( its borrowed to some one that want it. ) so I can't make tests for my self.

Please do it a favor and change that near Stevenson IEC set up for Löfgren A/Baerwald as follows:

overhang 16.8mm, offset angle 22.4° and pivot to spindle distance 228.2

please test this set up and compare against the one you are using and appreciate you comeback with your comments.

Thank you in advance.

regards and enjoy the music,
raul.

Dear T_bone: The Exel spreadsheet is very good idea.

About an increment on the EL the " land " you have to move is limited by the headshell slots and is posible that 3-4 mm makes no diffrence that you can hear.

If these kind of changes on the geometry set up beeen the only factor on the cartridge quality performance then is for sure that you can detect a minimum/tiny EL changes but there are other factors and IMHO other very important ones that a some levels preclude we can detect tiny EL changes. everything is important on cartridge set up but IMHO VTA/SRA and Azymuth makes the higher differences ( other than a matched tonearm. ).

Other that to use any of the protractors out there ( DT included. ) IMHO ( if we want to stay with mind on calm, even if we can't hear some geometry set up changes. ) a good alternative is to measure the most inner groove in our LP collection and take a choice with foundation on what are that LP collection if the 80%-90% of the Lps measures around 60mm then the IEC standard is the best choice in either Löfgreen A/Baerwald and Löfgren B and from these two if we want lower distortion at innergrooves then the choice is Löfgren A/Baerwald that additional gives you the same tracking error between null points and outer null points: this is very good compromise.

In the other side if the 80%-90% of the LPs in your collection are around 50mm or lower then you can choice between Stevenson or Löfgren A/Baerwald with non-IEC standard for the most inner grove data instead you change that input data for 50mm. I prefer this Löfgren A/baerwald that gives you sligthly ( tiny ) higher distortion that Stevenson at the very inner grooves but with lot lower distortion levels on all the remaining recorded LP area: this for me is very good compromise too.

That's why Löfgren A/Baerwald is the most used geometry set up.
IN the other side IMHO Stevenson was and is used by Japanese manufacturers because ( with all respect ) they did not a in deep analisis on the overall subject and its different alternatives, I already posted that I know this because I asked them about with no certain answers that could tell me they have in deep knowledge.

T_bone if it is true that this geometry set up cartridge/tonearm is something/subject really simple it could be very complex if we don't understand its foundation and alternatives.

I know many people don't understand yet and I don't blame any one for that. As I posted reviewers, audio distributors, tonearm designers and audio " gurus " does not understand in deep either, this is where a thread like this has a critical an important role for we improve our each one knowledge level on the whole subject.

The real value of discussions like the ones we have here and especially between DT and I IMHO always help ( one way or the other ) to lear, I can tell you for sure that I learned here too.

My attitude to " win " a discussion that I had on the past I left on the past even that sometimes you could think I want to beat DT or other person but it is not in that way, if I " insist " is because either I don't find true arguments against in the other person or because I'm challenged my own arguments/opinion till its fall/down or confirm it.

One of the best way to learn is through discussion with other people if what you move is to learn and not only who is right where you can't learn.

Regards and enjoy the music,
Raul.

Interesting comments on changing the Effective Length input on the arm's set-up geometry?
Those with a Fidelity Research FR-64s tonearm will know that the manufacturer's recommended spindle to pivot distance is 230mm.
This is precisely the figure I used when setting mine using Baerwald geometry.
It was only when I read Dertonearm's statement that Fidelity Research "got it wrong!" that I changed the spindle to pivot distance to Dertonearm's recommended 231.5mm with an overhang of 14.5mm.
Instantly I heard a difference across the entire presentation?
More relaxed, more focused and somehow 'sweeter'?
How could this be? Was it the 'placebo' effect?
As Raul claims that our ears could not hear the differences in distortions that are indeed quite small between different geometries, why am I hearing a perceived improvement in presentation?
Shouldn't I, at the very most, only hear a difference in distortion at either the beginning or end of a record?
Perhaps Daniel could explain to me what it is I am hearing and why the change of arm geometry has caused this?

Dear Raul,
Now we are getting somewhere... If you agree one can change EL on a given arm, despite what the manufacturer says should be the EL, necessarily the setup parameters will change. It should even be possible for it to sound better than normal should the EL be more appropriate than the original mfr's declared EL. Numbers could easily provide lower distortion results. Any tonearm where one creates a longer effective length than the mfr's own by the power of assumption will have lower distortion 'results'. I hope you see where this leads.

However we define 'white paper', I still think being open-minded is its own reward. 'Proven results' negate the need to be open-minded. However before that 'proof' arrives, speculation runs both ways. I choose my way and you can choose yours.

As to the suggestion that tonearm/protractor designers should provide the distortion levels for their setups, it might be useful. The problem becomes to what degree one takes it. I personally don't think most people want 9 sets of pieces of paper with each of their tonearms (3 curves - one each for DIN, IEC, and JIS standards, and possibly a fourth if the manufacturer's recommended setup results are not specifically one of the three), and definitely not 3 sets multiplied by the number of possible inner groove results (let' say 50mm-80mm every 5mm (makes 21 sets of distortion numbers per tonearm)). The best way to do so is to provide an Excel spreadsheet which contains the entire curve from 50mm to 146+mm for each of the curves, and a cell for inner groove and outer groove and the three calculations. But those exist already. If a mfr like VPI creates a non-standard mounting distance with non-standard (i.e. not one of the 'big 3') alignment curves, it would be nice of them to say it, but these things get out anyway.

In any case, the number of people who have multiple arms is limited. Among those, the number who want to fiddle with different setups for different records is relatively limited. Most want something to set and forget. And in that case, I assume that the prevailing wisdom per arm will always be caveat emptor! I do, however, encourage you to do so for your arm and template when it comes out.

Of course that to make comparisons the effective length must be the same because if we increment ( any increment, it does not matters how tiny. ) the EL distortions figures goes lower, the same happen when we increment the most inner groove distance on Löfgren A/B calculations.

R.

Dear friends: IMHO any manufacturer protractor with multiple set up alternatives, like the DT protractor, should/could gives his customers the chart with the different distortions level with each set up geometry/template for the set up.

IMHO we customers need to know at least which is the distoprtion level to decide which one to use, I think there is no reason for a protractor of this type does not comes with this main and critical customer information.

Dt, what do you think? could be?, thank you in advance.

Attitudes like the VPI manufacturer that undisclose the tonearm set up parameters IMHO is wrong because we are the customers and we have the right to know about, this kind of information is not a " subject " that you can attain a patent and even if yes: which the problem? why manufacturers put on sale audio items for " blind/unable to speak " people that things are we are not " blind " and certainly we can speak to ask.

Anyway, only a thought.

Regards and enjoy the music,
Raul.

Dear friends: I think that is important to remember that what I'm talking over the thread and IMHO over those white papers outside is to align the cartridge stylus/cantilever where the pivoted tonearm is only a tool and a " must " for do it. From the tonearm we need to know only the effective length and that's all.

The star is the cartridge ( is the source if we don't take in count the LP it self. ) but it needs the tonearm to hold it.

Regards and enjoy the music,
Raul.

Dear T_bone: Of course that we always can change the EL and I posted we can.

On the other subject and due that's so simple through the different VE calculators ( thank you VE! ) when you or any owner of the DT protractor have it on hand you can take the parameters from cartridge/tonearm ( no big deal. ) where the protractor was used for the set up and use that " numbers/data " on the VE calculators and confirm if you have lower distortions over the LP recorded area against the normal calculations or against the manufacturer numbers.

In this subject we really don't have to argue/ask anything other that : after calculations shows lower distortions numbers/values or not?, easy!!!! , here the subjectivity does not count what you, me or any other person could think does not matters at all ( well always an opinion matters but you know what I mean. ) the easy VE calculations tell us the real distortions levels against other set ups.

Btw, when I talked of white papers it's only those simple calculations and that's all.

Regards and enjoy the music,
Raul.

Raul,
Having read the papers, in my understanding of tonearm physics/math, there is no reason one cannot 'adjust' EL by 0.5mm and then come up with a new set of parameters derived from your preferred alignment (as long as the headshell is flexible enough (in terms of mounting holes)). It will no longer be 'official' but there should be room to play if one wants. Perhaps I have not properly understood. I will noodle it around a bit.

As to the other part, your idea of speculation and mine are obviously different. I think it speculative to assume that a change in the physics will have zero effect until a white paper tells me so. I have certainly not comcluded anything, but I am inclined to be open-minded, even without the white paper.

Dear T_bone: I forgot: +++++ " It appears we agree on that point (that using a different alignment than mfr.'s original design could alter resonance characteristics). " +++++

no and I can't say for sure if tha's happen till I have on " hand " white papers that prove it. What I'm sure is that two different approaches/solutions/equations calculated set up cartridge parameters give us two different distortion level performances.

I was thinking that I left clear that I don't buy speculations and normally I don't like to speculate as you.

Regards and enjoy the music,
Raul.

Dear T_bone: Normally the effective length does not change that input data, as I posted only if on porpose you want to change it.

The effective length is the main foundation on tonearm calculations through those known orthodox solutions ( Löfgren, Baerwald, Stevenson and the like. ) and is when you change effective length when all the other parameters calculated changed but not the other way around.

You need to read again those Dennes papers. Of course that you can manipulate/force on porpose every single input and output parameter on the geometry calculations but this is a different way/thing that IMHO is useless to discuss.

You can run an example of what happen on what you are asking: suppose that a tonearm design ( said: 270 mm on effective length. ) was designed according Löfgren B calculations and you want to make the cartridge set up with a different geometry like Baerwald or Stevenson geometry calculations for the set up, you can run this example through the " alignment calculator " tool in VE where you note that almost all the set up parameters ( including distortions level. ) calculated changed but the effective length is the same: does not changed.

regards and enjoy the music,
Raul.

Raul,
It appears we agree on that point (that using a different alignment than mfr.'s original design could alter resonance characteristics).

As to another question floating around out there... whether applying a different geometry than original to an arm could affect effective length (and therefore affect appropriate geometry parameters for the arm (which might affect resonance characteristics)... That remains an open question... Or maybe that too is not as difficult as it seems. I will have another think about it...

Syntax, Oscar was a smart man.

Dear Thuchan: The best for cero traking error with many trade-offs as the ones you pointed out.

It is a good choice?, yes it is if fulfil your mind sound reproduction expectatives to handle a cartridge for this cartridge can shows you the best it has.

Regards and enjoy the music,
Raul.

Dear Don Quichote, what do you think about linear trackers?

T_bone: We in our tonearm design don't take it either, we concentrate/focus on the main overall tonearm characteristics that makes " the difference " a true differences for the best and for the best quality performance with any known cartridge.

Regards and enjoy the music,
Raul.

Dear T_bone: Do you think that all or some of the tonearm designs out there taked in count all those characteristics ( cartridge, tonearm, set up and LP. ) I posted along that that tonearm design worked always best with the in theory tonearm design geometry choosed for those set up parameters ( overhang/offset angle. )?

I know that some tonearm designers are reading this thread and IMHO it will be " healthy " their each one opinion why they choosed what they choosed on the sole/aisle specific tonearm geometry design/parameters that is only one of several and IMHO not the main characteristic that affects the cartridge quality performance level.

Regards and enjoy the music,
Raul.

When I said: proved, means ( between other things. ) that always works and works with the lower distortions measures.

raul.

We know how its sounds but we don't know exactly and for sure why/how sounds that way, we all have only speculations about but nothing more than mere in good faith: not proved speculations.

As some of you I would like to have/know the true proved scientific overall theory behind the why's on quality performance level between one cartridge and one tonearm running a recorded specific LP and not only to improve my knowledge level on the whole subject but because when we know that ( in the future ) then we have the answers to all and each one questions and finally the right cartridge/tonearm set up.

Till that day IMHO we have to make our best effort with the proved tools we have on hand hopping/thinking that the best is waiting for us in the future.

Regards and enjoy the music,
Raul.

Dear T_bone: How many cartridges do you know? how many cartridges exist out there?, hundreds and each one resonate and performs in different way due to different cantilever build materials, different cantilever length, different cantilever shape, different stylus shape, different cartridge body build material, different suspension design and different suspension build material, different cartridge compliance, different cartridge weight, different, different and different all.

In the other side we have a tonearm that has its own resonance characteristics and different to other single tonearm out there due to different arm wand build materials, different headshell build materials, different arm wand shape, different tonearm bearings, different tonearm mounting base, different effective length, different, different, different and different all.

Each one of these cartridge and tonearm characteristics ( between other ones. ), one way or the other, has influence in the cartridge quality performance along accurate VT/SRA, VTF, Azymuth, overhang, offset angle, antiskate set up parameters.

Today no one here and no one out there can tell us in a precise way which and how is the influence of each one of those intrinsic cartridge characteristics, intrinsic tonearm characteristics and set up characteristics on the behavior and in the final cartridge quality performance for we can match for SURE one cartridge with one tonearm with the right set up on any recording.

The number of combinations of all those cartridge/tonearm/set up specific characteristics are almost infinity for we can say: " after our scientific research the only best match for this cartridge is this tonearm with this set up ", almost impossible we can do it.

But I don't finish yet, we have to take in count too the LP characteristics and characteristics on was is recorded there: off-center LP hole, waves all over the LP, different recorded velocities at different areas in the LP surface, thickness of the LP, resonance of the LP build material, etc, etc..
These LP characteristics has an influence too in the cartridge quality performance.

And now you think that an offset angle and overhang ( and we can ) different from what we can have through known equations ( Löfgren B, Baerwald, Stevenson. ) calculations choosing on those calculations whatever null points you want ( or what the tonearm designer choosed. ) could makes a difference that we can hear.

Adding thought to that: in theory ( for what you states in your idea. ) for each single cartridge/tonearm combination and for each one single LP we need different offset angle/overhang set up for be exactly " there ". Makes sense this for you?

I respect your opinion but I would like that you explain how is that? how can you/DT aisle/isolate that specific offset angle/overhang from all other each one cartridge/tonearm/set up/LP and from the combination of all those characteristics to know for sure that influence ( for the best or for the worst ) of the un-orthodox offset angle/overhang and that what we are hearing is because of them and not because the cartridge cantilever on playback is out of that offset angle set up that we made it in static playback condition or those tiny changes on VTA/SRA we have during playback due to LP imperfections where even there are tiny changes with the VTF too?

Where is that mathematic model that take in count all those different factors/characteristics that can tell us on playback ( motion not static way. ) which will be the quality performance level ( with lower distortions over the LP recorded area. ) in a cartridge and each one factor/characteristics " weight " in that quality performance level and of what kind is that influence?

I have no doubt and there is no doubt at all that you, Dertonarm, me or any one out there can't shows that great simulation model and IMHO till this happen ( I really hope some day its happen. I loved when this happen ) everything any one of us think or talk in the overall subject are mere speculations with no precise and proved foundation.

To make things " worst " we have to think that many of us likes some kind and different distortions and different distortions level even to some of us like higher distortions that other people or we are unaware to detect different distortion intensity levels due that our ears are not good enough, due that we are not trained to do it, due that we don't care about or due that our system has not that resolution level need it to.

We can go on on this thread making speculations of every kind but IMHO I think is useless.

Gentlemans, today we have what we have and nothing more. I hope we can improve in the future but certainly not an easy task on this whole cartridge/tonearm/LP subject. Today IMHO we have more questions than answers.

Regards and enjoy the music,
Raul.

Dear T_bone, I really try to be funny but it is so difficult to succeed. So herewith my comment on the linear
tonearms. Thy look to me as a very handsome guy but in the
intensive care room. All those tubes...

Regards,

Dear T_bone, you hit the nail on the head. For instance any derivation from a given tonearms design inherent offset angle results in an alternation of it's mechanical model - here it results in an additional breakdown torque, which has profound effects on the skating force. There are some tonearms out there which are designed in almost 100% compliance to Löfgren A/Baerwald IEC standard (all these tonearms being 9" effective length by the way). But then there are many tonearms out there which are not. And for those it is not just about aligning to certain null-points, but also that aligning to them does alter their resulting skating force (among other effects).
Usually one would say: o.k. just make the offset angle smaller and the skating force (resulting of the offset angle) will get less.
Not so as we have a design inherent offset angle and just apply a second one by twisting the cartridge in the mounting area in a different angle.
Thus resulting in a 2nd breakdown torque.
On the other hand there are tonearms like the Talea, which do feature an offset which is "free" to be determined on first glance, but which nevertheless follows Löfgren A IEC with clear given offset angle as specified by it's manufacturer.
This all should shine an additional light on the tonearm alignment topic and why there are different calculations, different focuses and different geometries.
Cheers,
D.

There is much talk about the zero points but I have not
seen any mentioned in particular. Herewith two of them which I got from Howard's article in Sterophile:
'For a modulated -groove-radius range of 56-146.3 mm, they
should be at 61.6 and 118.4 mm; or for 58-146,3mm,at 63.6
and 119.6mm.'

Regards,

Dear Jj2468, the linear tracking tonearms - in any incarnation we have seen so far from Rabco, Denessen, Goldmund, Versa Dynamics, Air Tangent, Eminent, Forsell et al -displayed mechanical issues, periphery problems and stability problems which did always crippled their undisputed tangential advantage.
Most audiophiles who ever ventured into tangential tonearms later moved to tonearms with 11" or more effective length to approach kind of "best of both worlds".
Means they minimize tangential tracking error by means of increased effective length while keeping the kind of "practicability" of the pivot tonearm.
Thus minimizing the tangential "advantage" of the linear tracking tonearm.
I have had all the above named tangential tonearms in most all their incarnations in my system in the past 30+ years.
They all were promising and were able - some more, some less - to produce great sonic results (at least for moments or short periods of time).
It were certain sonic shortcomings apparent in all these designs plus practicability issues and long-time problems for many cartridges which ultimately drove me away from tangential designs.
A 11" or 12" pivot tonearm precisely aligned leaves little place to shine for a tangential design, which always and only builds on it's zero tangential tracking error - by sacrifice of other important dynamic and mechanical parameters in a tonearm.
Cheers,
D

I, for one, wouldn't mind hearing more if people had information, anecdotes, or theories.

Hm, this is a brave idea. But it is like a walk through the Darkness without a light. Comparable with saying the word Jehova , "Prophet" or- God beware - "The Earth is round".....

The Audiophile community should be lucky to have such brave minds who do not refuse to go ahead.

Like Oscar Wilde once said:

"Be yourself; everyone else is already taken"

Or like Syntax:

There are only 2 ways of sound reproduction.
Good and none.

Perhaps it is my situation as intellectual Neanderthal, but I, for one, am willing to countenance the idea that a given tonearm design/construction may resonate differently (and therefore sound differently) if forces are applied in different ways (i.e. different offset angles than originally designed), the same way an arm may interact differently with different weight or compliance carts. This is not to say I think it would make a huge difference, but I think that given we are people who talk about getting VTF right to within a tenth of a gram, and levels matched to within a tenth of a decibel, and we change o-rings on the headshell collars, it is not too much to say that applying a LofgrenA geometry to a tonearm designed for a modified Stevenson geometry could sound differently than it would had it been designed with different angles and distances originally. I, for one, wouldn't mind hearing more if people had information, anecdotes, or theories.

Jj2468, this is a very good question. Why not playing the records the way they were cut? Due to the theroetical advantages linear trackers should dominate the market.
They do not.

First of all really good linear trackers are quite expensive, you need a precisely aligned horizontal bases to put the arm on, in most applications you need a vacuum driven guidance of the arm adding a compressor. To reach minimal friction, a precondition for linear trackers, because the cartridge moves via groove edge the total mass of the tonearm the alignment is not an easy one as one may assume.

The length of the cantilever and the compliance issue have some important impact on the interaction of tonearm and cartridge in this concept. This is with other arm concepts a little less critical, also because you have skating. With linear tracking arms you may not use all kinds of cartridges due to the friction issue which may lead to destruction of the rubber parts over time.

Taking into account all these preconditions you may reach excellent results with a linear tracker. I would not like to miss the advantages of this concept.

Somebody has to ask. Given this debate, why are linear tracking tonearms not more popular? Is the cartridge not parallel to the groove across the whole lp?

I use a Graham Phantom.

Just asking.

I did read the vinylengine article on the VPI jig. It was hard to take it to heart because the spindle to pivot for the 10.5i is completely wrong.

He says 262mm but in reality, it is 256mm.

Dear Gentlemans: First than all I want to say again that I'm not questioning any single protractor ( including all the ones named in this thread. ), I'm not questioning VPI undisclose protractor parameters or the DT ones but the " concept " that some tonearms needs " dedicated " geometry set up, first question here: why not all tonearms?

In reality the Löfgren and copy equations/solutions are to determine the exact point/place and " direction/orientation " where the tip on the cartridge stylus must be to fulfil a criterion that could be defined by the cartridge/tonearm owners or the explicit criterion on Löfgren A/B Stevenson or what ever for any given tonearm geometry design ( inclusive you could note VPI site that the designer never talk about: " our specific tonearm geometry " and he don't speaks about because he knew on the subject. Neither Stevenson. )

These are some of those criterion for set up parameters calculations:

+++ Löfgren A and is the solution that gives you the lowest possible amount of tracking error at the inner, centre and outer grooves while keeping this error equal at all 3 points. +++++

+++ Löfgren B and will gives you the lowest overall tracking error of any alignment method but with slightly higher error at the beginning and end of the record than the A method. +++++

++++ Stevenson - a variation on Löfgren geometry optimized for low distortion at the inner groove at the expense of increased distortion elsewhere. +++++

VPI, in reality ( I could be wrong, so crrect me if I am. ) take the criterion to have the lowest distortion in the last 1/3 of the recorded area ( something similar to Stevenson, but not the same. ). For doing this what VPI made was to change one of the three input data on the Löfgren equations ( this is an option but he can determine the desired null points and works for a derivation of the inner groove radius. The result is the same ), the change was in the most inner groove distance ( that in the case of Stevenson he made that that input data coincide with the inside null point and that's why in the last one groove the distortion is cero. ) for change the null points in a way that fulfil that criterion but the foundation of any of these changes are still the Löfgren equations that any one can " manipulate " by algebra to fulfil his criterion.

The undisclose VPI set up parameters IMHO was something with almost no reason for that because in the very first moment that his tonearms and VPI jig/protractor be on customers hands it was very easy to know those set up parameters and this is what happen when VE people take their knowledge and time to analize which were those set up parameters and when they have on hand run calculations against Löfgren A/Baerwald and B . Well you can read it here:
www.vinylengine.com/vpi-tonearm-geometry.shtml.

You can note that in the models 10 and 10.5 even in the last 1/3 of the recorded area ( VPI criterion ) the Löfgren distortion is lower.

Through the thread I posted several times the importance of those three data inputs on the calculations and what happen if we change it:

+++++ “ I repeat again, in the Löfgren and clones solutions/equations you need three and only three input data for the calculations: tonearm effective length, most outer groove distance and most inner groove distance and is according these three numbers ( that you can choose as you want it. and for any reason you have. ) that you calculate the overhang and offset angle. “ +++++

+++++ “ In my last post before the one I sended to you I explain the Stevenson approach as an example on how we can manipulate/change the input data to achieve a different set up parameters. “ +++++


+++++ “We don't need any other geometry parameter to make a tonearm/cartridge set up: effective length, overhang and offset angle are all we need. Even we don't have to care on the null points.
The null points are calculated and used for other things than stylus-cantilever/tonearm geometry set up. “ +++++

+++++ “The Stevenson A cloned/solution ( adopted by several Japanese tonearm manufacturers. IMHO with out in deep analysis. ) is not something with " new " equations, Stevenson only wanted that at the inner groove the tracking error be cero so he taked one of the three input numbers ( in the Löfgren formulas. ): most inner grove distance as one null point and that's all.
This " solution " gives you almost cero tracking error/distortion in the last 30 seconds of a LP with a higher distortions on all the remaining LP surface than in any other " solution ". +++++

+++++ Any one of us can change ( in the Löfgren equations. ) this same input number and Voilá! we have a " new " Perry/Jones/Lopez/etc solution!!!. +++++

+++++ “Now, if we change the data input to force better " figures " at inner groove that could be in detriment of higher distortions in the other 90% of the remaining LP grooves “ +++++

As any one can read on those Graeme F. Dennes white papers any change on that input data makes a change on null points. In those equations the null points are not input data but a calculation output of the equations. Of course, in mathematics you can re-arrange by algebra and could make that the null points be data input.

So, it is IMHO that the criterion is what define those three input data for calculate: overhang, offset angle and null points positions and not the " specific tonearm geometry ".

Other that the most inner groove distance ( inpput data ) we can change ( if the slots's length in the headshell permit it. ) the tonearm effective length data for a higher one to achieve better distortion figures but again not because tonearm geometry it self.

I could be wrong but in this thread and all over the net there is no single real scientific evidence that that is true.

Anyway, I think too that in one or other way the discussion was a learning one and I say this because due to many of the persons posts in the thread I was wrong when I thinked that some of you were " familiar " with all the terms ( terminology ) used on the subject and the most important the meaning of each term.

What's true is that today our knowledge level on the subject is higher than " yesterday ".

regards and enjoy the music,
Raul.

Dear Geoch, I am sorry, but I thought this to be clear from the very start. Maybe a kind of "too specialized"-perspective of mine. It is always about the two null points, where to set them and how to manage to keep the "graph" determined by them rather "down" on the distortion scale.
This is what you can actually "see" in a graph.
What can't be "seen" is the effect minute changes in these null points actually have on certain tonearm designs.
Cheers,
D.

Dear Jazzgene, indeed - usually Yip uses Löfgren A/Baerwald for his MINTlp protractors.
Cheers,
D

Dear Daniel,
You are perfectly clear this time at last!
But how you could manage to drive me crazy for so long, it's beyond my understanding.
As I figured at an earlier post, it's all about setting new null (zero) points. Perfectly understood & respected by me.

That is for sure. I am using the Mint protractor for my VPI 10.5i arm right now. The Mint is made with Baerwald IEC, I believe.

Dear Dertonarm, My argument was not against the arm but against the designer arguments (phenomenal hearing capabiltys) BTW I am not used to argue
against lifeless objects.If I understand you well you or
your tractor can fix the problem(s). But more interesting, I assume, is the article by Keith Howard in Stereophile (March,2010) about the 'arc angels'. From him I also borrowed 'my' point about the O points . According to him the 'accurate cart. alignment is very difficult to achive, not least beacause the overhang and offset have to be set within extremly tight tolerances...' He also mentioned the 'whole hystory' from Percy Wilson till Stevenson. I was suprised to learn about the diffrence between the tracking error and the tracing error but more in particular that what Dennes calls Lofgren B 'just doesent't make sence to me'. Alas the whole technical story is to complex for a lawyer.
Which brings me btw to Thuchan.
Dear Thuchan , the reduction of complexity in casu is for
me a two O points protractor with O points in the right place. No need for me to comprehend all the technicalitys.
Like a average car driver who knows that there is something
called 'motor' in his car. So 'die praktische Vernunft'(the practical reason) is something differnt from
'die reinen Vernunft' ( Kant's 'pure reason'). Anyway the fact that you are still optimistic person despite your extended experiance deserves admiration.

Regards,

Regards,

Dear Nandric, any VPI tonearm can be aligned to calculation curves different from the one Harry Weisfeld favors.
And there are far more VPI tonearms out "there" than many think.
Cheers,
D.

Dear Geoch, my calculations for several tonearms are based on my point of view that the last 3rd of the grooved area is more sensible to distortions and tracking error because in the 3-dimensional stereo groove the difference in angle between the inner and outer groove increases with decreasing radius.
That is creating already a difficult situation for the stylus' contact area.
Stevenson tried to solved this "stereo"-problem by simply setting the 2nd zero error at the DIN and IEC inner limit of grooved area.
Usually I aim to find a 2nd zero point between Baerwald/Löfgren A and Stevenson. Resulting in about as low average distortion as Löfgren B AND only slightly more maximum distortion compared with Baerwald/Löfgren A.
Important point IMHO is, that "my" maximum distortion figures are at the very beginning of a record - i.e. in that area, where the difference between inner and out groove wall is lowest and therefor least sensible to tracking error.
"My" idea of tangential calculation tries to get the best of both worlds while taking into account the fact that we are dealing with a 3-dimensional stereo groove here AND that the most critical (read: loudest, most dynamic, highest amplitude) passages in many genres of music do occur towards the end of a piece/movement.
So "my" calculation usually sports VERY low distortions in the last 15% of the groove.
I know what I am doing and I do know exactly why.
There is no secret here, but just a comprehensive survey and a critical look at the tonearms geometry, the stereo groove and the requirements faced with the records cut the last 5 decades.
No one has to follow my ideas nor do I postulate they are the one and only ones. I know however that they do give excellent sonic results and do take into account issues others have missed.
On the other hand, Löfgren A/Baerwald, Löfgren B and Stevenson - DIN as well as IEC - are all readily available as UNI-templates.
And there are some 9" IEC-based tonearms and small collections of modern records only (with rather long lead-out groove), where Löfgren B is certainly best.
But then there are too tonearms like a FR-64s and records like old Mercury SR, DECCA SXL, Verve and Impulse (to name just a few) which do "fare" way better with "my" calculation.

The UNI-Protractor is an universal precision positioning and alignment instrument. Independent whether you use "my" calculation for a few specific tonearms or whether you go for any of the "standard" calculations. Those are all options one can choose or dismiss.
You may noted, that I have not postulated a "Dertonarm"-alignment curve.
I only did some individual calculations for some specific tonearm designs.
That's it. Because generalization isn't always preferable.
I for one are neither on a crusade nor do I preach to follow my point of view only.
I have designed an instrument the serious audiophile can use with as broad a choice of options as possible.
Nothing more - but nothing less.
Hope I could clarify the point.
Cheers,
D.

Dear Nandric,

"reducing the complexity means to me not being able to deal with it"

not necessarily. reduction of complexity was and is sometimes a way of gaining new insights - one will believe or not. And it is also a survival pattern in some difficult situations enabling the individual to cope with it.

Of course you are right the psychological implications are also evident when it comes to results being feeded by personality habits avoiding or defending actions. You may conclude from special communication styles and patterns if the individual is able to deal with complexity or not, mostly using only one or two special behavior patterns showing over time. In this way most of us are not very well trained or prepared dealing with complexity.

thanks for your compliments. You are right I am a very optimistic person but having gained experience about "the real world" I do think that we need controversial discussion to some extent. This is what makes it different to the glossy magazines.

We all, I think, recognaze the individual right of belief
in our own hearing. So anybody is entiteld to believe in
his own ears. But to ekspect that anybody else should believe in your hearing is something totaly different. So
no wonder that only some of us use the VPI tonearms.
Regards,

If those 0 points mark the places whitout any distortion
why are we not able to hear them? One should akspect some
special (Aha!)feeling 'around' them. I myself would ply
only those parts on the records because my aim is perfection.

Regards,

Travbrow :
"A tracing arc with a specific distortion curve should have the same geometric error and distortions regardless of the arm, cartridge stylus or if the record is stereo or mono, I thought? "
Good question!
With our restricted knowlege till now, this is a fact.
So, what is going on with Daniel's proximity ?