Uni-Protractor Set tonearm alignment

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.

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

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,

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