Uni-Protractor Set tonearm alignment

I think I understand passion.I am from the Balkans were people never try to avoid any war whatever. Thy are also
willing to participate in any as well start new one without
specific reasons. Ie pure passion. The western 'cowards' in
contradistinction need always some 'very strong reasons' for such an undertaking and have usualy no better then 'economic reasons'. I am not familiar with the Mexican hystory but from Zapata ,etc. one may quess at least some symilarity. There were times when fighting was a
way of life. If I am well informed Dertonarms direct predecessors were European champions.

Regards,

Well if Raul's tonearm works out as well as the phonolinepreamp, we can call it Edsel.

IMO Raul's green eyed monster and old habits returned just after you indicated your tonearm will go into production June 2011 :>)

I am waiting for Raul's breakthrough in Tonearm Design. For 3 years now...
But it should be crosschecked with a good Phonostage, a design which can handle the 0.2mV without distortions.

Dert

IMO Raul's green eyed monster and old habits returned just after you indicated your tonearm will go into production June 2011 :>)

I am looking forward to see if you have designed a better mousetrap.

cheers

I don't know enough about alignment geometry to understand or even question which geometry is best for my particular arm/LP type. I will follow the recommendations of those who know more than I do and listen to the results.

For me, the two aspects of Dertonarm's Uni-Pro which are the most exciting are the extreme precision with which the instrument is designed and then manufactured and the apparent ease with which the user can see these tiny parameters.

My MintLP gave me much better results than my supplied SME cardboard protractor, but it is difficult to use and certainly not universal. If I change my arm or cartridge, I will need to order another one.

I don't want to cut into potential sales of the Uni-Pro, but it seems to me that this would be an excellent tool to share among two or three audiophiles who live near each other. I've considered a similar arrangement with something like the expensive Furutech Demag unit or even a strobe speed check disk. I find that I'm sharing/collaborating with a couple of fun audio buddies more and more these days. We all learn in the process and perhaps save a bit of money to buy more LPs.

Dear Dertonarm: Last time Agon deleted a thread with this same " discussion " subject ( as a fact the last one was the second time that happened for the same. ), I have 6-7 posts on those deleted threads and in one of them you give the " new " Fr set up parameters and result that distortions levels all over the LP were higher that any other approach/solution knowed.

So, till you don't show those lower distortions and better tonearm set up and only talk about telling us that there are something better IMHO is not enough. I repeat on that thread you try to prove it with out success but with a totally failure.

You ask why I return on this subject and the answer is because you insist on " nothing " and not only me but other people want to know where is that " true ". I'm not the only person that ask you about with no answer, Goech made it too in this thread as other made it on those threads I mentioned. Like all I would like to learn on that issue. If you don't want to talk about or you in reality have nothing then why bring it ones and again that ghost subject.
The people here in Méxiso say: " of tongue I eat 10Kgs. ".

On the Ikeda subject was many months ago when I posted on the quality performance of the SAEC/Ikeda combination. At the end the best cartridge performance was attained with the Mission The Mechanic tonearm.

Regrads and enjoy the music,
Raul.

Dear Raul,
you can run your Ikeda in the 506/30 and I am happy to hear that you are satisfied with the performance, but - IMHO ... - the 506/30 is not exploring the performance limits of the Ikeda.
Cheers,
D.

Dear Raul,
Löfgren has not "detected" anything. Neither did Baerwald nor Stevenson nor any of the other persons which did calculations regarding the tracking arc and where to set the 2 tangential zero error points. You are missing one of a few vital pints here.
This is simply applied mathematic - geometry to be precise.
The last facts in known geometry of relevance to our small world which were "detected", were so many many centuries ago.

It is not just about average, peak weighted and/or maximum distortion and comparing those figures.
We have that way to evaluate things in all kinds of statistic everyday life and they are widely used to generalize issues by politicians worldwide with known intent and effect.
Is there a better tangential calculation with better distortion figures for a FR-64s possible - better than Baerwald ( Löfgren A), Löfgren (B) or Stevenson ?
Yes - of course.
Same for a good dozen great tonearms out there.
Why so ?
This is kind of generalizing arithmetical average vs detailed INDIVIDUAL calculation focused on an individual topic.
And maybe taking a few tiny issues into account which shouldn't be neglected.
Funny thing here is, that for the last month it seemed not to trouble you too much that I have designed the UNI-Protractor.
But now you seemed to change your mind and fall back to - very .. - old positions and habits of yours.
"False Prophets" who supported that LOMC-subject and forced a poor man to spent thousands of big dollars for those cartridges.
O.k. - message received.....
I believe that we all soon will see the decline of LOMCs into the mist of history - at least that's the prophecy.
Cheers,
D.

Dear Downunder: You said it not me.

I'm not talking about DT protractor but about what Thuchan posted so please read that post.

With all respect to those gentlemans: How do you name persons that cloned the Löfgren equations and present/introduce a " new " solutions as his solutions ?, false prophet is to much to you? ok change the name but things does not change. I think that " false prophet " is very elegant for that people.
Downunder, try to clone dollars or Yens and I can tell you that you could end on jail.

If you think you waist your money with MM/MI cartridges then you do it by ignorance and as you said: is part of our day by day hobby and like me you learned in that MM/MI subject in the same manner that I learned on the protractors subject after paid for my ignorance.

I bought and spended thousands of big dollars in " tons " of LOMC cartridges thank's to my ignorance and thank's to all those " false prophets " that supported this LOMC subject.

Which name do you like for this kind of people?

Regards and enjoy the music,
Raul.

Dear Raul

I use a $2 Ortofon tractor with my AS-309 and I get zero inner groove tracking issues.

I also now use the free Graham alignment jig instead of the Mint LP version. I get better sound from the so-called imprecise Graham jig. Did I waste my $$ on the MintLP - not really - part of the hifi hobby I am afraid.

You seem to be inferring that Dert is a "false prophet" in bringing out yet another "Universal" alignment tool. I guess you are adding Yip from MintLP and well as Feikert?.
You also infer that anyone spending $$ on these type of devices are "ignorant"

Some may say I followed a "false prophet" in wasting some of my $$ on some MM cartridges.

Guess what, this is all part of out enjoyment of this hobby and we all live and learn.

I would say everyone who has spent there hard earned $695 on Dert's alignment tool has gone in with their eyes open and probably a deal of skepticism.

Frankly Dert has left his credibility wide open if the tool is not as good or better as what is out there now - but good on him for putting his $$ where his mouth is.

I for one will quite openly tell how this tool works in my system - good bad or indifferent.

So Raul, how about you be a gentlemen and play nice for a change and wait for some of the folks who have paid real $$ before you call folks "false prophets"

have a nice musical day

Dear Thuchan: Almost all what you read in my latest post was writed for other people on the net and I only bring here with my " touch ".

Thuchan, the " black thread " was discovered many years ago.

regards and enjoy the music,
raul.

Dear Dertonarm: I run my Ikeda cartridge with the 506/30 with very good quality performance level and as you know the Ikeda cartridges are one of the lowest compliance cartridges out there.

Agree, the SAECs runs very well with MM/MI cartridges too.

regards and enjoy the music,
Raul.

Dear Thuchan and friends: +++++ " we all have spent a little too much in too many different solutions regarding finding the exact geometry for our tonearms............. for someone who deals with more than one tonearm/cart was calling for a universal approach " +++++


yes, a lot of time. IMHO from the point of view of tonearm/cartridge set up geometry there is no exact ( specific. ) geometry for a pivoted tonearm with slots on the headshell, let me explain it:

the only known " solution " to cartridge/tonearm geometry set up are the Löfgren equations ( 1938 ), all the other " solutions " are clones from Löfgreen ones ( Baerwald ( 1941 ) Stevenson ( 1966 ) and the like. ).

The original Löfgren was name it 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. There is a small rise and fall in error between these points.

The second Löfgren solution was named 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.

Both solutions are Universal ones and can be use it with any pivoted tonearm with slots in the headshell it does not matters the tonearm geometry design. If the tonearm is J or S shaped or what you " imagine " is not important for the set up.

This two Löfgren solutions/equations calculate ( in any set up ) the next set up parameters: overhang, offset angle, null points, linear offset and mounting distance.
These calculated parameters comes from the equations that have three known and only three parameters: tonearm effective length, most inner groove distance and most outer groove distance, there is no other single parameter need it or taked in count for the overall calculations: so the geometry tonearm design does not matters for this calculations, the only tonearm design factor important is that be a pivoted one.
Of course that you can make changes on this starting calculations parameters, this is that we can change the tonearm effective length for a different calculated set parameters or we can change the most inner groove distance tooo if we like it. Every time we made one of these changes we are changing too the traking error and tracking distortion values for that set up.

As you can see does not exist: that this or that kind of calculations is better for this or that tonearm, you are free to use it as you want: Löfgren A or B, there are no more, as I told you all the other " solutions " are mathematically identical to the Löfgren ones but only with different notation and arrangement.

It is ironic that for many of us Baerwald is more " familiar " name than Löfgren when was LÖfgren the creator of those two and only solutions.
The Baerwald solution is identical to Löfgren A as is the Stevenson B.

But like in many disciplines in the past and today exist the " false profets " that only create confusion/mix up but really does not add something new in favor of that discipline.

In numbers which are the differences between Löfgren A and B?, well the offset angle in both solutions are the same what is different is the overhang and by consecuence the mounting distance.

But do you know how much varies that overhang value?, around 0.4mm ( longer for Löfgren B solution. ) depending on the tonearm effective length.

Now, do you know how change the %distortion between Löfgren A and B?, well: máximum distortion between null points the difference is around 0.17% and the average ( over all the LP ) is 0.04%!!!!!

Do you think you or any one can detect those so low distortions differences?, certainly not. We need at least 1% of distortion to start to detect and no all the persons are so sensitive, there are persons that can't detect distortions on the 5% values and of course that depend which kind of distortion we are talking about but in general what we are talking on tonearm/cartridge set up we just can't.

I told you I own at least 9 protractors and any one of them is a Universal protractor but my ignorance in the past years made to ignore that fact ( universal ) and due to my ignorance level I followed to those " false profets " that taked advantage of my ignorance level and start to bought any single protractor out there.

Of course that there exist different protractor accuracy level that are important on quality performance but if the protractor accuracy is important there are other set up parameters that are important and critical, maybe more that the accuracy on protractors. At least two of those critical set up parameters are VTA/SRA and Azymuth and almost the 100% of the problems that many persons have with inner groove distortions and Shshshss on the voices recorded.

Let me tell you about: I never been very " anal " on the overhang/offset angle set up ( right now I'm using a 20.00 protractor with great success. ) but I take care a little more in deep on the SRA/Azymuth set up and you know what?, I never had/have inner groove distortion problems or exaggerated shshss on voices.

Thuchan, with that 20.00 protractor I just listened the 1812 Overture on Telarc where the most demanding score range ( cannons's shots. ) is at the inner grooves and the quality performance I heard was not only CLEAN but a great one!!!!, yes for me SRA/Azymuth are critical as is the own cartridge abilities to track along the tonearm it self.

I'm not saying that overhang/offset andgle/PTS distance are not important of course are important but there are a lot of things that define if we could have inner groove distortions or not.

Over the time I visited several Agoners places/homes like: F. Crowder, A. Porter, D. Deacon, S. Doobins, etc, etc , let me to tell you that in no one of this systems I heard inner groove distortions or exaggerate SHshshss on voices recorded and in no one of these places I see an " anal " attitude on protractors set up even in S.Doobins place he changed a cartridge using a protractor and taked 2-3 minutes to doing and even that that cartridge set up was not fine tunned everything performs first rate.
What I seen at those Agoner's places was a more in deep care for SRA/Azymuth/VTF set up even at " anal " level like in Doug's place.

Thank's God I learned ( actually, still learn every single day. )on the whole subject and in other audio subjects that permit that today I don't follow any more to those " false profets " or false myths created inside the AHEE because our ignorance level. Best medicine for this?: questioning always questioning ( what if that's not true or what if that white is not white? ) and testing, why? how? who? where? or just " please show me " prove me it's true.

Regards and enjoy the music,
Raul.

"I haven't worked with the SME 309 yet"

Dertonarm,

Thanks for your comments. Come to Houston and you can re-setup mine when it gets here.

Y'all be cool,
Robert

"Perhaps you should start a specific thread about the different SME arms or do a search in the archives. There is lots of information regarding these arms. You could also email Sumiko, the US importer."

Peterayer,

I am aware of all that. I have been participating in online forums since the early 80's when we had to dial in on 300 baud modems. I thought this illustrious group could help me avoid sorting through much irrelevant material. If you are an admin here perhaps you can give me Audiogon search tips. Even Google gives lots of trash. Although their recent changes have helped.

Robert

Dear Henry,
there is - IMHO ... ;-) ... - a direct correlation between low compliance and the amount of energy transferred into the tonearm. Certain bearing principles can handle that energy better - others fare less well.
This is kind of a sensible topic - I am a bit reluctant to discuss toneram bearing principles in public, as I do not want to step on any toes.
If o.k. with you, I will address your question in detail tomorrow in a PM direct to you.
Cheers,
D.

Dear Daniel,
Interesting?
How about unipivots?
Do they like low compliance cartridges in your opinion?
Cheers
Henry

Dear Henry, knife-edge bearing tonearms do not like cartridges which do transfer a lot of energy into the armwand. Thus SAEC tonearms - despite the fact that some do sport a pretty high moving mass - in general do fare better with cartridge featuring high compliance.
So expect your WE-308 to perform pretty well with most of your MMs, but not with a FR-7.
As I still do favor LOMC and some with really low compliance, the not optimal energy handling abilities of the knife-edge bearings were abandoned in an early design stage.
To achieved my goals I needed very hard and rigid bearings and an armwand which can transfer energy ASAP without torsion or inner resonance.
Cheers,
D.

Dear Raul,
understand very well. maybe we all have spent a little too much in too many different solutions regarding finding the exact geometry for our tonearms. I became happy with the Dennessen but did also see the limits for other installations when getting to know that some data inputs from some manufacturers for their own arms were not the right ones for special cartridges we are using. Therefore the situation for someone who deals with more than one tonearm/cart was calling for a universal approach. I have big hopes that the Uni-Pro is a good answer for those multi-users but I also wait with an assessment until I have made my own experiences with the sets ordered.

Dear Daniel,
Interesting comments on arms with knife-edge bearings?
The SAEC arms with double knife-edge bearings enjoy quite an enviable reputation amongst the 'vintage' fraternity with Thuchan even ranking the 12" versions competitive with the FR series tonearms?

I wonder if you might expand on the weaknesses you find in this solution.......especially since I have a new addition to my arm collection arriving shortly.......namely an SAEC WE-308?
Cheers
Henry

Dear Geoch, it is an important feature, but it is only one important feature among a good half dozen others.
Knife-edge bearings do have a good bundle of problems too.
Some of them are quite severe and do limit the performance of a knife-edge tonearm - that's why I personally abandoned the knife-edge bearing pretty early in the development of my design.
Low friction isn't everything (in fact - it is negligible in all better tonearm bearings today).
You should address this topic in a separate thread and I can assure you that you will get many posts and comments by some of the more active A'goners as well as by some tonearm designers.
Please do start that thread.
Cheers,
D.

Dear Daniel, it is my fault not to be clear about this. My LPs are all from '70s and I don't have but a few classical symphonic music so, I prefer the Loefgren B IEC, all the time.

Dear Geoch, be careful not to fall into a "trap" here: Löfgren B IEC is NOT a priori better for those records cut close to the inner label!
In fact Baerwald IEC does sport way lower distortions towards the inner groove compared with Löfgren B IEC.
Löfgren B is way better in the middle 3rd of the grooved area, but has it's highest distortion figures towards the cutting limit.
A very dangerous error if one thinks that Löfgren B is better for wide cut records - it certainly is not!
Löfgren B is all about lowering the average distortion figure - but it does so at the expense of the inner grooves.
If you want the lowest distortions possible in or towards the inner groove - which is wise BTW .... especially if you listen to symphonic music and have a large collection of records from the 1950ies and 1960ies - you should have a good look at Stevenson, as it puts the focus exactly on that: lowest distortions and zero error point at cutting limit.
This again is just a general guideline - not meant as a generalization.
Cheers,
D.

" dynamic balanced mode has a few good advantages vs static balanced mode - regarding guiding a cartridge with compliance through the groove of a record which is by nature NOT flat."
Excellent!
But what if this feature is the most critical ?
And what if we accept that probably the bearing friction on tonearms with ball bearings is considerably more than knife-edges, cardanics & unipivots, and this advanced feature can not incorporated in them or in a air bearing tonearm...
Does this pointing us the way of designing better tonearms?
Can we include this feature in a more sophisticated bearing ?

Dear all, the last post by Syntax with the two photos showing the different cutting area ( and those weren't yet the absolute extremes of either school - have a look at some of the DMM cuttings from the 1980ies !! ) shouldn't be overlooked, as these pictures nicely illustrate a core problem of tonearm alignment.
The reason behind many "sibilance" and "distortion" problems and one of the reasons why longer tonearms in general are superior over a wider band of records.
Cheers,
D.

Dear Geoch, I do not want to step on any toes here, but in general, a "cardanic" = gimbal bearing does in no way hinder a design approach to give a tonearm dynamic balanced mode.
It is VERY difficult however to apply dynamic balanced mode to a uni-pivot tonearm (it is possible however..).
It is just, that there are "camps" in audiophile analog community and at least a few of them do not really "favor" dynamic balanced mode.
Why this is so, is beyond my limited horizon.
Interesting to note however, that many of those great japanese tonearm designs which have stood the test of time - Micro Seiki MA-505 and MAX, Pioneer/Exclusive EA-10/Pa3, Fidelity Research FR-64s and 66s - do feature dynamically balanced mode.
From the point of view of mere physics and technical engineering, dynamic balanced mode has a few good advantages vs static balanced mode - at least regarding guiding a cartridge with compliance through the groove of a record which is by nature NOT flat in a technical sense.
Cheers,
D.

Dear Syntax,
Thank you for your nice photos.
It is clear that for ALL of my records, (your first photo) the prefered TONEARM'S ALIGNMENT is the Loefgren B.
The problem that I'm still have, is that I can't indentify those particular points on the TONEARM'S GEOMETRY, that dictates to a specialised/individual/unique alignment !
Not to be confused with the alignments of the B,L,S, IEC or DIN, (that depended by the way the LPs were printed on vinyl).
I'm really sorry that I'm posting about this again, but I've just figured a possible misunderstanding might occur about my quest.
What I mean is : When you look a tonearm, how can you see those points that require a modification in it's geometry ?
Is that all about setting new null points ?
I don't expect an answer, I'm posting this just to clarify.
Thanks again.

The bearings are now the same (i.e. ABEC7) on all the Series V-derived models (= Series IV, 309 etc)and have been for a couple of years now.
You can hear this direct 'from the horse' mouth' if you look at a series of videos about SME on Youtube.Here is the URL of the first of the four (all relatively short):
http://www.youtube.com/watch?v=T8tbyVRsrKM
Best regards,

At last! For first time ever someone has noticed that a dynamicaly balanced pivoted tonearm is better.
I'm wondering do you feel that it is also neccessary (if it might be possible to integrate in) for the cardanic arms (Pluto 9A, Reed, Davinci, etc)?

Dear Robob, I haven't worked with the SME 309 yet, but his headshell features single mounting holes and hardly any option to alter overhang and/or offset. As such it shares the very same "camp" with it's big brother the "V".
The SME V does feature - as Geoch pointed out - better ball bearings and is a dynamically balanced design ( which - at least IMHO - is an important feature in a pivot tonearm trying to set the state of the art ).
The SME V is - among it's brothers and offsprings - still the best tonearm. Due to superior attention to detail and better parts incorporated.
The other SME tonearms are "trickling-down-products" from the SME V.
Cheers,
D.

Syntax,
I presume you prefer yours stirred and not shaken. Great photos as always.

Robob,
Perhaps you should start a specific thread about the different SME arms or do a search in the archives. There is lots of information regarding these arms. You could also email Sumiko, the US importer.

If I can recall, it is about abec7 Vs abec5 bearings.

Dear Geoch,

back to the roots:

Here you see a record with a last track
cut absolutely to the limit

here is a very modern LP with much more space & a lot of tracks
different cut, different cutting machines

You see, an Alignment with a Nullpoint which is at the beginning of the record and another one in the middle can't be the best one for the first record....
and here is also the reason for different Geometries in Arm Design.

Listen with ...

Thanks a lot, Dertonarm & Thom Mackris
It seems to me that what one really needs to align the SME V is: (i) some device for measuring the actual effective length once you have mounted the cartridge of your choice (this device needs to be very accurate), (ii) some device to allow you to set exactly the right P2S distance (again, this needs to be very accurate), and (iii) a grid that allows you to check cantilever alignment at one of the Baerwald-IEC null points.
If you have all these, then results should be perfect!!!
Best wishes,

"In the case of the SME V (which really is a very special issue) there is however way less options for variations in alignment/calculation curves.
The SME V is a super strict 9"/Baerwald IEC-standard tonearm. "

Is all of this about the V also true of the 309 even though it is a removable headshell?

Anybody know where there is a good comparison of the V vs the IV vs the 309? I am not clear on the differences (other than the 309's removable headshell and the V has dynamic VTF?) and nothing I see on the SME site spells out the differences/advantages of the more expensive versions.

Thanks for any enlightenment you folks can give,
Robert

I understand what you were trying to accomplish, Pgtaylor. This was an illustrative example for those who haven't worked through the math.

BTW, do you really think that the Feickert has the precision to measure to .003"? If you can do this with that tool, you're a better man than I am.

Cheers,
Thom @ Galibier (the "h" is silent)

Dear Thom_mackris, indeed, this is rather the fine print in tonearm alignment is may already be well beyond what a good portion of the analog department want to muse or think about.
I just wanted an instrument which provides the best possible universal alignment results with super simple handling and comfortable feeling.
I will continue to design a few devices which will nicely work with and are based upon the UNI-Pro.
A super precise and truly new P2S-measuring tool will be introduced end this month. This will come together with an easy goniometer to determine offset-angle fast, easy and precise.
I am considering this rather an add-on of interest only for a few dedicated audiophiles who really want to study the subject.
Furthermore - also end this month - there will be a special USB-microscope w/strong cold light to be used with the UNI-Pro and which can be exchanged with the magnifier and uses the same cut-out frame on the UNI-Pro's main frame as the magnifier.
This will allow magnification 20x to 200x (similar to the Dino-lite) and will come with all features, adjustable and with software for Linux, Windows and Mac.
Plug and play within 10 minutes.
Allows view of the stylus on the spot on your screen with actual measuring tool and photo option.
This will allow the most enlarged and "recordable" look and will further ease as precise alignment as possible ever to the ones among us who are a bit troubled by eyesight showing our advanced age...;-) ....
Cheers,
D.

Dear Pgtaylor, the SME V's alignment is indeed a very special problem. The Schroeder is different and offers the user a wider range of options.
But back to the SME V, which was when introduced anticipated like no other tonearm ever before or ever after.
The SME V is unique in the sense that it's offset and effective length (at least it’s designers thought so and intended it to be that way...) are fixed and pre-determined. Problem is, that SME Ltd. took for granted that each and every cartridge manufacturer would strictly follow IEC standards regarding stylus-mounting slots distance. Which of course they did not.
Now there is the legendary SME slide base to allow sliding the whole tonearm back and forth. That way the arm kind of "moves to the wanted alignment spot".
In theory....
The fact that the fixed offset angle of the fixed headshell isn't really a feature which eases things in any way did not really appeal to the SME engineers in their strive for setting the technical frontier in tonearm design.
Now can one align the SME V precisely with ANY cartridge mounted ?
Yes.
As long as the protractor reacts to a change in P2S as well as to a change in effective length automatically.
The UNI-Pro individual templates do offer for a given tonearm (and there is a individual UNI-Pro template for the SME V of course) an optimized spot of alignment - the corresponding effective length and ( in the case of the SME V ) the P2S are direct results of the alignment and are automatically generated.
Without any calculation required by the user.
In the case of the SME V (which really is a very special issue) there is however way less options for variations in alignment/calculation curves.
The SME V is a super strict 9"/Baerwald IEC-standard tonearm.
You can't really align him a Loefgren or Stevenson curve with good results.
I hope this answers your question, but you are welcome to get in touch directly in case you have further questions regarding your SME V.
Cheers,
D.

Dear Thuchan: I like almost all use audio after market items, I own no least than 9 different protractors but you know why?: because my ignorance level over time.
Fortunately that level improve over the years.

Regards and enjoy the music,
Raul.

Tom Mackris.
Of course you are right when you say that the extra stylus tip-mounting holes distance cannot simply added to the manufacturer's stated effective length for the tonearm. In fact I was aware of that. What I was trying to illustrate was a way to measure the actual effective length (rather than calculating it) by effectively drawing a line (but in fact using the Feickert trammel to simulate it) from the stylus point to the arm pivot 'as the crow flies' (and then measuring it). Surely this (leaving aside for the moment any practical difficulties in achieving it) would give the correct measurement (?).
regards.

Pgtaylor, Dertonearm …

It goes without saying that we're venturing into the fine " ether" of tonearm setup. With respect to SME's and the upper end Schroeder tonearms, the effective length changes require a bit of trigonometry, or a CAD program to determine, and producing a protractor dedicated to a particular cartridge needs to take this into account.

Follow me …

1. The effective length is the STRAIGHT LINE distance from the stylus tip to the tonearm bearing.
2. The cartridge is offset, per Baerwald/Loefgren/Stevenson geometry

So, merely adding the effective length difference will not give you the correct results (close, but no cigar). A cartridge whose stylus is 1mm further forward than a statistically "normal" cartridge increases the effective length by less than 1mm.

I just modeled a Tri-Planar on my CAD tool. I chose this arm because I had the numbers handy: effective length = 250mm, offset angle = 21.949 for Baerwaald. I assumed a 40mm long headhell (the offset component) for this exercise.

A cartridge with a stylus positioned 1mm forward of the statistical norm increases the effective length by.9275mm, for a net effective length of 250.9275mm. Simple addition would predict 251mm, or a variance of .0725mm (.0028"),

.0028" is within the threshold of audibility for a high performance analog rig, which is why everyone on this thread has justifiably been whipped into a frenzy over a better tool.

The takeaway from this is that any protractor generated for arms like the SME V, and the upper end Schroeders, needs to take the effective length, the length of the ofset section of the arm wand, and the proposed geometry into consideration.

I posted the drawing to the following URL for anyone who's interested: http://www.galibierdesign.com/images/forum/Eff_length_Model.pdf.

Cheers,
Thom @ Galibier

Dear Thom_mackris, you've hit the nail's head. Although it was Syntax' who deserves the credits for the phrase you quoted.
I think we all too often lightly and needless give away quality of performance right here at the very start and without realizing. This is the "very core point" I wanted to address with the UNI-Pro. Enabling everybody to very precise alignment with ease and universality.
Cheers,
D.

Hello Dertonarm,
I would be very interested to hear what you have to say about using the Uni-Protractor with tonearms that do not allow the cartridge to be moved backwards and forwards in the headshell, like the Schroder and the SME V, IV etc.This question was raised by T. Mackris but has not answered yet, I think.
Surely with arms like these the crucial thing is to determine the effective length as accurately as possible and then set the appropriate pivot-to-spindle distance, again as accurately as possible.
The producer of the Mint Protractor is of course aware of this problem, and asks that, when ordering a protractor for a given cartridge with non-standard cantilever length (distance between stylus tip and mounting holes), customers should either indicate the cartridge manufacturer's specification of the stylus tip to mounting hole length or, failing that, provide a close-up photograph of their catridge viewed against a measure.
The problem here is clear enough: since the point of a dedicated protractor like the Mint is to provide a highly accurate alignment template for a given effective length, the whole enterprise is compomised if the effective length cannot be determined accurately to start with - and the photograph technique is by its very nature approximate.
It was this consideration that stopped me from ordering a Mint for my SME V & Benz combination.
Can the Uni-Protractor (or any add-on that you have in the pipeline) help with this problem?
My approach so far has been to measure the effective length, using the trammel that comes with the Feickert Protractor. This is simple enough: first choose a point on the template disk and rotate it until the stylus drops exactly on this point. Lift the stylus and block the turntable so that no movement is possible. Then place the spindle hole of the Feickert trammel over the point (so that the latter is in the middle of the hole), and then measure the distance to the centrepoint of the arm pivot (easier if you have removed the 'bridge' on your SME). Read off the effective length, and then use Conrad Hoffman's template generator (or similar)to make a template for precisely that effective length.
Of course there are several points in this where inaccuracy can creep in: (i) in trying to ensure that point on the disk is exactly in the middle of the spindle hole in the trammel base; (ii) in judging that the vertical pointer is exactly over the centre of the arm pivot; (iii) in reading off the measurement from the scale on the trammel.
Despite these possible sources of inaccuracy, this method has given me by far the best alignment so far.
Sorry for boring everyone with this detailed description, but my question is: can the Uni-Protractor - maybe via some sort of add-on - provide a way of eliminating the approximation inherent in the above system?
This is a genuine question, not a covert plug for anybody else's protractor.
Best regards, and congratulations on what you have created.
Peter

Thank you Syntax for this excellent post.
Replies for developing a state of mind like this one, can help us maybe even more than the actual product !

There was a thread 'Why more then one tonearm?' or something. Well we have the answer as well as some kind
of Copernican turn. We need to measure the distance from
the lead out groove till the spindle and reorganize our
LP collection accordingly. Assuming,say, 4 categorys corresponding to 4 different tonearm geometrys (otherwise
5) we will be able to use the right tonearm with the right
LP's. One need to measure first to decide how many tonearms
one will need , mark them derafter accordingly and then
apply all the acquired knowledge by each LP we intend to
play.

Regards,

Dertonarm,

Thanks for the clarifying points. You mentioned one point which may have been lost on folks, because everyone's attention is captured by the design of the Uni-tractor and your selection of geometries. I want to highlight your point:

This is probably a better investment than swapping cartridges, which won't show us anything new (at the end of day).

All too often (and in every area of the signal chain), we as audiophiles neglect the importance of setup, as our attention is always captured by the latest and greatest component.

The individual debating the purchase of the next $1,000 cartridge (we don't have to get to the pricing $tratosphere) would do well to ask himself the following question:

"have I provided my current cartridge every opportunity to succeed?".

If the answer is "no", you are randomly wandering about, and are depending on luck to reach success (not that I'm against a bit of luck here and there ~grin~).

Cheers,
Thom @ Galibier

Same 10X peak lupe I'm complaining about in my earlier post. Put it on top of an eraser just like the pix on Mint website. It fell down, rolled and bumped the cantilever. Luckily no serious damage done. Derto supplied magnefying glass seems will do the job.

"Joel had considered the idea of providing a Mint protractor with the tonearm, but we see examples above of individuals who cannot relate to this wonderful tool."

I certainly can relate to this tool. I also can relate to the fact that with the supplied 10x loupe, with my cartridge, it is not practical as I can't get a good view of the cantilever. So it doesn't matter how accurate Mint may be. Of course with another type of loupe, it might work beautifully.

If Dertoarm's allow for easy view and the alignment is precise, I think it will be a hit. Plus, I've been wanting to try out Lofgren.

.....it is quite important to focus the attention on the last 1/3rd of the groove.
There is good evident reason for this: most climax in symphonic music is towards the last minutes of a movement and thus most likely situated towards the inner label. Very vulnerable to distortion and miss-tracking ...

That's what's all about...in the last 10 years I had so many discussions from owners who had problems with distortions, sharp "S" vocals in voices and some of them found their peace with Arms which have huge deficits in the reproduction of the full swing. I never had that, I never thought about that because I always had the right adjustments. Much later when I thought about "these" problems & listening to originals from the 50's+60's AND reading a lot of information how they were recorded, mastered, I knew, there are the differences. We also have differences in Tonearm Geometry, most Buyers think, when they pay for it, they get a perfect calculated and designed product. Some are really great and some are different in Performance from day to day. Anyway, it was necessary to think about a product which serves well for a majority of Audiophiles who are really interested in a better analog performance. Independent from price, a good alignment is also mandatory for a Rega RB250 as well as for Davinci user, when he wants to listen to old records which ARE the Golden Age of Analog. Listening to 80gr Records from 1995 won't show big differences, but when going back with the proper alignment and you will listen to LSC-Pines of Rome, you will hear what's the differences in Tonearm Design. It is a time jump into a recording session made lots of years ago. This is probably a better investment than swapping cartridges, which won't show us anything new (at the end of day).
More important is, we spend our time after working to "listen". Maybe one or the other will listen to his records and they will "tell" him something completely new...

Good sound (or analog Performance) is sometimes based on a very simple Principle: Knowledge about >>what is responsible for what<< and Precision.

Dear Dertoarm, no complain on the pricing, but maybe you can extend the introductory price. I believe that most of the members here are on the state of "wait and see".

Regards,