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 T_bone: Yes, I'm using the VE comparator IEC and DIN too for a fixed pivot to spindle distance.

IMHO we need at least one calculation data that be the same on all and any calculations, this data is: 231.5mm pivot to spindle that's is what states DT ( btw, Nandric posted that all those DT numbers comes from that magazine. I can't be sure because I don't find that German magazine from 1984. It suppose that the reviewers made and change those FR manufacturer parameters. ) and if you see and read again that comparator VE link that you already sawed you can attest that that PTS distance of 231.5mm are common for Stevenson, Löfgren B, Löfgren A/Baerwald and obviously the custom one that's where that data comes and the one DT states.

In your posts you give the average distortion values for different set ups/calculations that obviously are different from the VE where exist that common PTS data for we can compare apples with apples because in that VE comparator the Stevenson, Baerwald and Löfgren B are the " answers " against the original ( DT numbers. ) parameters with the same tonearm pivot to spindle distance.

Said all that that average distortion values are:

IEC ( OA: 20.325° ): Original/DT 0.421%, Baerwald: 0.387 and Löfgren B: 0.347.

Same OA but DIN: original 0.43%, Baerwald: =.43% and Löfgren B: 0.387%

In no one of this calculations the Original has lower overall distortions. You and any one can see/read the graphics on all those calculations to see the each one behavior's curves.

IEC ( with OA: 20.574° ): original 0.419%, Baerwald 0.387% and Löfgren B 0.347°.

DIN shows: original 0.421%, Baerwald 0.43° and Löfgren 0.387°. Only with DIN standard and only to Baerwald the original is slightly better.

Now, what could tell us all these calculations?, IMHO what some way or the other we already posted here: we can change input data and set up parameters and distortions levels change for the better or worst but even that the Löfgren A and B solutions has the best overall " answer " .

T_bone, I never states that there are no trade offs in any set up geometry approach as a fact it is this ( that exist always trade offs. ) what I suppoted and I don't think I'm supporting " absolutes " because that " absolutes " has no trade offs.

I still " trust "/support and like the Löfgren A and B solutions as the ones with very good compromises for any data we introduce in the calculations. Of course that if we introduce the wrong data then we have a wrong results.

I don't know what you think that for make comparisons at least one data must be common to all calculations/approaches: I support this single common data for comparisons.

Thank you for your time and information because help me to be aware where " things " comes and why your numbers are a little different from the VE ones that I taked to support my opinion.

I can't understand why DT don't disclosed 50 posts before along that 1984 German magazyne where I understand the whole FR information/numbers comes.

Thank you again.

regards and enjoy the music,
Raul.
Dear Raul, I assume that I quoted from 'Das Ohr' in the thread about the FR-64 S. According to the reviewers the
geometry in the user manual was not optimal and they proposed 231.5 mm spindle-pivot distance and 146mm eff. lenght. Those are the 'FR numbers' you are refering to.BTW
Dertonarm was also reviewer by 'Das Ohr' in those time so
I thought wrongly that he must be of my age. No idea if those numbers are of any help but I used them for my FR-64
already in 1984.

Regards,
Dear Nandric: Thank you, yes are the same numbers we are talking about.

Regards and enjoy the music,
Raul.
Der T_bone: The same happen ( original with higher distortions. ) if the common data is EL ( 246mm ) instead PTS one in either IEC or DIN standards.

regards and enjoy the music,
Raul.
Dear Pryso: +++++ " I do continue now to wonder if Dennesen considered other alignment calculations and rejected them, or if he simple accepted Baerwald because it was the most well known? " +++++

IMHO the precise and true answer only Dennesen could have it but I think that this could been take it in count for that Dennesen designer:

Löfgren A/Baerwald 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. This seems to me a good overall compromise.

Regards and enjoy the music,
Raul.