Uni-Protractor Set tonearm alignment

Dertonearm,

I'm extremely interested in this topic, as my owners are beginning to ask me about your new tool.

My first reaction is to have them buy one for me (for my Durand Talea, thank you) and I'll experiment with it and let them know. All kidding aside, I applaud your herculean efforts and the beautiful photos of the exquisite machining. My concern however is only with results. Any advantages of your tool fall into one of the following:

1. The precision with which this geometry can be implemented - can superior results can be achieved, or alternatively, can equivalent results can be achieved more easily. Easier is important to some, and "better" is important to everyone.

2. The superiority of your chosen alignment geometry

This is what I will base my recommendation on.

Before delving into the above questions, let ask you the following, on behalf of a customer who owns a Schroeder Reference. Can you confirm the following for me:

1. The protractor is "programmable" - coming with a set of some 30 templates to be used for common arms. Any arm not on the list requires a template costing $69. Is this correct?

2. Implication for Schroeder Reference owners. If the above is correct, then my customers with Schroeder references will need a template for each cartridge they use, due to non-standard stylus to cartridge mounting hole center. Is this correct?

-----

As I read through threads on the Mint LP protractor, I note how some of individuals struggle with viewing the stylus using the supplied loupe.

This issue is one that touches all alignment techniques involving one's having to view the stylus. It's not specific to the Mint LP, except perhaps because the Mint (like all arc protractors) tells you in no uncertain terms when you are off (by magnifying your error as you attempt to trace the arc). An addendum to the instructions would be helpful - telling you that there is no universal loupe, and that experimentation might be in order.

So, if you have freed individuals from having to use magnification to view the stylus, you have broken new ground and I applaud you.

Now this thread has gone off track with the discussion of the ideal alignment geometry. Of course it's important, but it needs to be kept distinct from the tool used to achieve it … UNLESS, you have arrived at an alignment you deem to be proprietary. If this is the case, then the perspective purchaser has only one way to implement that geometry - by purchasing your tool. I'm fine with that. Your research deserves to be rewarded.

So … what's my advice to my customer base? In plain and simple language, "it's your money and you take your chances".

Now, if you'd like to prove to the world that your methodology is superior - that someone can achieve better results with your tool over a well implemented arc protractor like the Mint LP (irrespective of geometry) - then I would propose one or both of the following experiments.

Experiment #1: Tell us the geometry you'd use for a world-class tonearm like the Durand Talea. We'll have Yip make up a protractor using this geometry and see which one best serves the music over a broad collection of records. The problem with this experiment is that the Mint LP might do a better job of implementing your geometry better, but we might not like the geometry.

Experiment #2: Implementing Baerwaald, Loefgren, and Stevenson with both your protractor and the Mint. This has the chance of giving us the broadest view - separating accuracy of implementation from geometry preferences.

Ultimately, all four geometries should be tested with both protractors, but I separated the experiments as I have, since I don't know your intellectual property considerations.

-----

If I appear to be holding your feet to the fire in this post, you are correct, but please realize that this is because I take my recommendations to my customers very seriously.

My initial impression of your beautifully made tool is that you have possibly selected a superior geometry - at least for individuals who listen to a large percentage of records that extend into what is today, the lead-out section. I've never been a fan of favoring inner groove performance at the expense of having higher distortion over the bulk of the stylus' path. One that further looks to bias the alignment beyond Loefgren's equations by extending the LP inward is something I'd be wary of.

There's no free lunch … other than a linear tracker, of course, and even that's not "free" … except from a geometry perspective.

Now, I would love to be proven wrong - that you have both (a) created a better mouse trap, and (b) that you have selected a superior alignment.

Lastly, now that you are a manufacturer, what is your real name and what city are you based out of?

Good luck in your new venture.

Regards,
Thom @ Galibier

Hi Raul,

Not a lot of itme these days, but this thread was brought to my attention by a couple of customers.

Up until this point, I have been recommending arc protractors for owners of all tonearms with adjustable headshell slots. The Mint combines availabilty and high quality.

The Schroeder Reference, Reference SQ and DPS arms are a challenge, because different cartridges yield different effective lengths (I know you know this). I try to make it easy for my Schroder customers and I send them card-stock protractors made for the effective length that their cartridge yields.

After that, it's up to them if they want to order a Mint or a Wally, or whatever.

At my suggestion, the Durand Talea has a small nipple on the underside of the bearing. Joel supplies a machined aluminum bar that mates to the record spindle and the nipple to adjust the pivot-spindle distance to within about .004" (some intentional play in the record spindle hole due to turntable manufacturer variances). A quality protractor brings you to the last .004" by rotating the arm (or, on a Galibier, by adjusting the armboard with its vernier, fine adjustment).

I appreciate the heroic effort undertaken by Dertonearm. I don't take this lightly, but there are some big claims being made, and I want to separate the issue of chosen geometry from how well a tool achieves the geometry.

On the subject of geometry, I found the ad, and noted that the protractor allows for Baerwald, Loefgren, and Stevenson for both IEC and DIN (6 combinations). I must have misread an earlier post about another alignment geometry being employed.

So an experiment using the Unitractor and the Mint (note that I did not use the word "shootout") would have more validity. Only 6 protractors need to be made for it ;-)

There are some nice usability features on Dertonarm's design, and these should not be underestimated. The fixed position magnifying glass (set up for the focal length of the magnifier, it would appear), will help many.

So, everything counts when you're trying to design a new product. A more "accurate" tool that a large variety of users cannot effectively use is not as good as one that is slightly less accurate but more users can use to its full potential.

I need to make something clear. I am NOT saying that the Unitractor is less accurate. I am merely pointing out that ease of use is is an important feature. Nothing more.

Cheers,
Thom @ Galibier

Dear Raul,

I don't disagree with you, but at the same time you have to accept the fact that we live in an ever specialized world. There are people like Dertonearm, Yip, etc. who spend their time focusing on protractors.

People like Frank Schroeder, Bob Graham, Tri-Mai, Joel Durand, et. al. spend their time thinking about, and improving their tonearm designs. I'd prefer that they do this, in light of the superlative aftermarket alternatives in alignment tools.

In my setup experience, the most difficult geometrical parameter involves getting the pivot-spindle distance correct. The machined indexing bar that Joel provides, along with Bob Graham's method are but two excellent solutions to this problem, and both give you an excellent head start on the alignment process.

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.

So, rather than dictating the the tool to his customers, he provides them with an arc protractor printed on card stock. It serves as a no-risk introduction to his customers. If they don't relate to it, there's no loss. I recommended this solution to him, as my customers have responded very positively to this approach.

I think you know that nothing is free, and if he were to provide a Mint protractor it to his customers, it would still be accounted for in the pricing structure. Even with an OEM arrangment, the nature of markups mean tha the customer would pay more for the Mint than by buying it direct.

As you can see, there are people like Dmailer who see no reason to go beyond the card stock protractor. Can they do better? Likely. Do they care? Obviously not.

As manufacturers, it's not our position to dictate, but rather to recommend.

Would I criticize a tonearm manufacture from providing sophisticated alignment system with their tonearm? Absolutely not! Would I criticize them for not providing one? Same answer.

Cheers,
Thom @ Galibier

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

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

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)