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Tonearm recommendation

Hello all,
Recently procured a Feickert Blackbird w/ the Jelco 12 inch tonearm.
The table is really good, and its a keeper. The Jelco is also very good, but not as good as my Fidelity Research FR66s. So the Jelco will eventually hit Ebay, and the question remains do I keep the FR66s or sell that and buy something modern in the 5-6 K range. My only point of reference is my old JMW-10 on my Aries MK1, so I don't know how the FR66s would compare to a modern arm. So I'd like to rely on the collective knowledge and experience of this group for a recommendation.

Keep the FR66s, or go modern in the 5-6K range, say a Moerch DP8 or maybe an SME.

Any and all thoughts and opinions are of course much appreciated.

Cheers,      Crazy Bill
wrm0325
fleib
1,124 posts
 

Dear Raul, You wound me deeply. I was the greatest tutor in all of the Americas, and look what I have become. I have failed you. Now I am just a hollow shell of a tutor, like an empty tortoise shell in the sand, I'm a dead tortoise tutor, not to say I tutor dead tortoises, but my tutoring, he is very sick. I thought I answered all your questions, but usted no entiende.  Si me lo permite.

Yes, the Loefgren calculations are correct. They are the basis of all the others. The spreadsheets, VE calculators are the same thing in different formats. Your answers should be the same. If you start out with L the spreadsheet or calculator will show you M distance, offset, error, etc. for each alignment.  I don't have your spreadsheet. I told you how to access the calculator. You don't need to log in.  Follow my instructions and it's all there. If you can't use the spreadsheet or calculator I suggest you build something else. How about a nice headshell holder display block? 

Regards,



Ag insider logo xs@2x
rauliruegas
13,101 posts
 
fleib: Finally! a more direct answer from you, good. I have no time now to give my point and I will give latter on.

Thank's.

R.
dover
2,249 posts
 
Fleib/Lewm

I calculated the effective length required to achieve a 21.5 degree offset with Lofgren A for the Dynavector arms. This would result in the cartridge being in line with the vertical bearings.

Using the formula
Effective Length = (r1+r2) / [ (sine(a)*[ 1 + ((r1+r2)squared / (r1*r2))] ]
where r1/r2 are the nulls & (a) is the offset angle.

Result is effective length of 254.97 and overhang of 16.158.
This is impossible with the Dynavector unless you extend the length of the arm or headshell.

This underpins that one really cannot judge an arm without at least trying the geometry that the original arm was designed for. Furthermore Rauls contention that he altered the mounting distance for Lofgren A to optimise the performance on his Dyanvector was probably wrong unless he modified the arm.  

fleib
1,124 posts
 

Dover,

**Result is effective length of 254.97 and overhang of 16.158.
This is impossible with the Dynavector unless you extend the length of the arm or headshell.**

The arm has 2 non-coincidental pivots, an ingenious design.

Regards,

lewm
13,148 posts
 
My point was not about whatever is the "correct" geometry for a DV505/507, because I don't know what that is, except it's likely to be at least close to Stevenson.  My point was that twisting the cartridge/cantilever in the headshell such that the arc described by the cantilever is not in the same plane as that of the vertical bearing of the tonearm did in fact seem to produce unpleasant distortion (as opposed to "pleasant" distortion).  This is in agreement with Dover's line of thinking.  I heretofore kept this to myself, because this is a single observation of mine.  I was very interested to see that Dover and some others have arrived at the same conclusion.

In my case, I own a UNItractor, from Dertonearm.  He kindly supplied me with a template dedicated to the DV505.  That's what I now use to align my DV505, and it results in "correct" alignment of the arc of the cantilever vis a vis the arc of the vertical bearing.  Separately, I also have demonstrated to my own satisfaction that the DV505 comes close with standard Stevenson, using a Stevenson protractor I downloaded from VE for free.  But I don't now use that; I use the UNI for the DV505.  Dertonearm's design is complex and a bit cumbersome to use, but it is also ingenious and permits very accurate alignment because of the ancillary tools he provides.  However, I cannot quote distances in fractions of a mm; I'm just a slave to the UNI. Life is short.
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