Uni-Protractor Set tonearm alignment

I think Daniel added the ruler as a "estimate" tool and not for a precise measurement. If you look at the positioning arm, it does not go to the spindle so it can't give P2S measurement without a complete re-design.

I believe if you are very careful, you can get a very precise measurement of P2S with the ruler supplied, though. Use some CD cases to lift the ruler so it is completely parallel to the platter. Look at the ruler directly from above as well.

Downunder, I fell into the same trap as you, and you are completely right: The Feickert provides a comfortable distance measurement.

What I did: I fixed Dertonarms scale tool on the Dennessen, putting the black middle round over the spindle as a horizontal bases, and put the Azimuth transparent block on top running it against the scale (see last image on my page).

I am now absolutely precise on the distance and in the next step I do use the UNI-Protractor.

Of course you are right it would be fine to have it within one tool. maybe Dertonarm will consider a UNI-Protractor v2 combininig these capabilities.

Best & Fun Only - Thuchan

Dear Halcro,

After further engagement with the Uni-Protractor I can share your experiences. Especially regarding the "frosted mirror design". It is sometimes very difficult to hit the point. If I am using a lamp into the direction of the needle it helps a little to find the exact location.

regarding the P2S measurement I have made a suggestion in my answer to Downunder. At the moment I do think a two step approach, P2S measurement, then using the UNI , makes the most sense.

It is not a 9000 Dollar arm which comes in a 200 Dollar box, but you understand that this tool is designed for other purposes. Nevertheless I wish i had a wooden box to put in the fully build up Uni-Protractor just to take it out for usage when neccessary.

Best & Fun Only - Thuchan

Thanks Jazzgene and Downunder,
It's interesting to read all the first impressions as they begin to trickle in?
It seems there are some who like the full mirror whilst others may prefer a 'frosted' mirror? Personally, I never understood how to correctly use the full mirror in a parallax reflected mode so perhaps that would be an advantage?
As Daniel is now finding.......you can't satisfy everyone?!
Thuchan, who always strives for the best possible solutions, has devised a perfect way to utilise the supplied steel rule but his description is not as good as his photo of the solution (a picture is worth.........). Hopefully Eckart, you can find a way to post your picture?

I have been rethinking the steel rule comments and in Daniel's defense, there are many more turntables with 'fixed' tonearms than those accommodating changeable tonearms. I myself lived for 25 years with a Rega Planar 3 with a 'fixed' Hadcock GH228 so why would I worry about Spindle to Pivot dimension?
Of course in those days before the Internet Forums, I didn't even appreciate the importance of critical alignment?
And those of us who in fact do have adjustable tonearm mounting devices, would certainly already have a Spindle to Pivot measuring device already.
So I can understand Dertonarm's thinking here although something tells me that whilst the UNIprotractor 'arm' is not centred on the Spindle, there might be some mathematical formula which, when the micrometer is wound down to its minimum position, could still be used to check Spindle to Pivot dimensions?
Perhaps Daniel could consult with a mathematician about this?

This leads me to another question about the UNIprotractor.........if someone has a turntable with a fixed arm which had been incorrectly positioned by the Dealer or Manufacturer by say 2-3mm (which is very easy to occur), what effect does that have on the accuracy of the UNIprotractor?

Another question which gives me even more nightmares?.........if each arm is set according to a different geometry/alignment, how do those with cartridges mounted in interchangeable headshells swap those headshells between arms?
I certainly don't want to have to align each cartridge when I change headshells and then change it again on another one?
Life is for 'listening'.......isn't it?

Dear Albert,
you may get some comfort in changing headshells if you are using those ones with a fixed cart like the Fidelity Research FR-7 series in the same arm. This is among other reasons why I have one FR-66s on each Micro. Also the EMT JSD 6 Jubilee which I regard as a best buy for its quality and its wonderful sound provides a fixed solution.

The Ortofon RMA 309 allows changing EMT & Ortofon carts "nearly on the fly" not changing anything even not the weight in most cases.

Bu to be honest the real fun we have when "working on our arms and carts". Otherwise we cannot use our alignment tools resp. the Uni-Pro.

I also wonder why it shouldn't be possible to move the Uni-Pros arm to the middle as you describe it.