Uni-Protractor Set tonearm alignment


Looks like Dertonarm has put his money where his mouth is and designed the ultimate universal alignment tractor.

Early days, It would be great to hear from someone who has used it and compared to Mint, Feikert etc.

Given its high price, it will need to justify its superiority against all others. It does look in another league compared to those other alignemt devices

http://www.audiogon.com/cgi-bin/cls.pl?anlgtnrm&1303145487&/Uni-Protractor-Set-tonearm-ali
downunder
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.
Dertonarm, I for one would like to know what the Dennessen is based on. Enlighten us if you know.
Dear Genesis168, despite what some here on Audiogon did say past early winter in a deleted thread, the original Dennesen Soundtraktor is 100% Löfgren A / Baerwald IEC.
"My" calculation for the FR-64s has nothing to do with Stevenson.
The original manufacturers specs weren't all that bad ( they are close to Stevenson but did put the 2nd null point even closer to the label - apparently Isamu Ikeda did have a lot of Mercurys and early DECCA SXL in mind when he choosed that alignment ...;-) ....) , but they did not do the geometry of the FR-64s any right.
It is not enough to find the white papers and the alignment calculator in Vinylengine - it is more about understanding what is actually important in a calculation curve for a stereo record ( and yes, - it has more and slightly different requirements compared to a mono record) and where to position the 2 null-points to get the best performance.
As said before - the "common model" we find everywhere is a bit simplified and takes too little into account that we are dealing with a 3-dimensonal stereo groove here - not mono.
At least - not me.
Cheers,
D.
Dear Halcro, to avoid any misleading info here, let me state that "my" calculation for the FR-64s gives - even with VE calculator ...;-) ..... - for the last 66% (i.e. 2/3 of the grooved area) of the record an average of 40% less distortion than Baerwald/Löfgren A IEC.
The maximum distortion with my calculation is in the lead-in groove where is is about level with Stevenson IEC.
That is about all what my calculation has in common with Stevenson........
The average "unweighted" distortion is right in between the figures of Löfgren A/Baerwald and Löfgren B.
Being very close to Löfgren B for most of the time and with approx. 45% less distortion compared to Löfgren B in the last 8-12 mm of a given record.
I "have" 5% lower "average" distortion compared to Löfgren A IEC/Baerwald and 20% less maximum distortion compared to Löfgren B (and his maximum is in the inner groove and my is at the lead-in groove).
I am perfectly fine if someone doesn't "like" my approach, but I know why I chose it and the results (if properly re-calculated in VE) do proof my idea even in simple graphs.
In any case - my approach is justified just as well as Löfgren's, Baerwald's or Stevenson's.
What a simple graph can't show, is that a distortion figure in the 1st third of a record is a completely different thing compared to the last third of the same record.
So finally I urge everybody to muse about the ever decreasing radius of a LP and what that means for the stereo-stylus.
This topic was discussed in the 1980ies and 1990ies in Germany and Japan (if I remember right ... in Japan even earlier) - the fact that you don't find any white papers about this in the web doesn't mean it wasn't done. There is a lot of information about many more core audio topics missing in the web.
Cheers,
D.
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.
Halcro

Well, I wrote in in the FR Thread - which was deleted - to someone who wrote about 65x about "distortions".
Based on some hyper prosecutions about distortions (you-know-from-whom) with Fr-64s+Dennesen+231,5mm P-to S I used my Graham Phantom II, which has an alignment System from B. Graham to adjust the cartridge precisely to a point (which one) and the alignment from cantilever is also possible.
The result was identical. Spot on.
For those who live in a rubber cell it is probably not easy to understand, but it is boring and a waste of time to repeat it over and o