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 Geoch, I do not want to step on any toes here, but in general, a "cardanic" = gimbal bearing does in no way hinder a design approach to give a tonearm dynamic balanced mode.
It is VERY difficult however to apply dynamic balanced mode to a uni-pivot tonearm (it is possible however..).
It is just, that there are "camps" in audiophile analog community and at least a few of them do not really "favor" dynamic balanced mode.
Why this is so, is beyond my limited horizon.
Interesting to note however, that many of those great japanese tonearm designs which have stood the test of time - Micro Seiki MA-505 and MAX, Pioneer/Exclusive EA-10/Pa3, Fidelity Research FR-64s and 66s - do feature dynamically balanced mode.
From the point of view of mere physics and technical engineering, dynamic balanced mode has a few good advantages vs static balanced mode - at least regarding guiding a cartridge with compliance through the groove of a record which is by nature NOT flat in a technical sense.
Cheers,
D.
Dear all, the last post by Syntax with the two photos showing the different cutting area ( and those weren't yet the absolute extremes of either school - have a look at some of the DMM cuttings from the 1980ies !! ) shouldn't be overlooked, as these pictures nicely illustrate a core problem of tonearm alignment.
The reason behind many "sibilance" and "distortion" problems and one of the reasons why longer tonearms in general are superior over a wider band of records.
Cheers,
D.
" dynamic balanced mode has a few good advantages vs static balanced mode - regarding guiding a cartridge with compliance through the groove of a record which is by nature NOT flat."
Excellent!
But what if this feature is the most critical ?
And what if we accept that probably the bearing friction on tonearms with ball bearings is considerably more than knife-edges, cardanics & unipivots, and this advanced feature can not incorporated in them or in a air bearing tonearm...
Does this pointing us the way of designing better tonearms?
Can we include this feature in a more sophisticated bearing ?
Dear Geoch, be careful not to fall into a "trap" here: Löfgren B IEC is NOT a priori better for those records cut close to the inner label!
In fact Baerwald IEC does sport way lower distortions towards the inner groove compared with Löfgren B IEC.
Löfgren B is way better in the middle 3rd of the grooved area, but has it's highest distortion figures towards the cutting limit.
A very dangerous error if one thinks that Löfgren B is better for wide cut records - it certainly is not!
Löfgren B is all about lowering the average distortion figure - but it does so at the expense of the inner grooves.
If you want the lowest distortions possible in or towards the inner groove - which is wise BTW .... especially if you listen to symphonic music and have a large collection of records from the 1950ies and 1960ies - you should have a good look at Stevenson, as it puts the focus exactly on that: lowest distortions and zero error point at cutting limit.
This again is just a general guideline - not meant as a generalization.
Cheers,
D.
Dear Daniel, it is my fault not to be clear about this. My LPs are all from '70s and I don't have but a few classical symphonic music so, I prefer the Loefgren B IEC, all the time.