A Copernican View of the Turntable System

Dertonearm. Yes, before your protractor existed I had aligned my DV505 on my Lenco using Baerwald. The cartridge had to be twisted inward in the headshell, and the sound was not so good, which I tended to blame on the cartridge, since it was my first time hearing the Lenco, the DV505, AND this particular cartridge (which I think was the Ortofon M20 FL Super). However, when I finally found a Stevenson protractor (for free on Vinyl Engine) and used it to re-align the cartridge, things got a lot better. I concluded that the DV505 was designed for Stevenson or something very near it.

Dear Lewm, youe assumption is correct - the Dynavector tonearms are designed following Stevenson IEC calculation. Stevenson IEC was pretty popular among japanese tonearm designers in the 1970ies and after.
While I am not really a fan of the Stevenson-curve (very high derivations in the last 3rd of the groove - then steep nose-diving to zero on the IEC/DIN standard point of inner groove limit ) - it has some merits.
But substituting Baerwald with Stevenson is jumping out of the frying pan and straight into the fire. Before going for Stevenson IEC, I would rather try Baerwald DIN or UNI-DIN instead - even with a Dynavector.
Cheers,
D.

No. I will stick with Stevenson for DV. In fact, this experience (Baerwald vs Stevenson on the DV505) was a good lesson for me on the importance of geometry.

And now, back to your local Copernican view. And as Thuchan says, "all in fun".

Dear Daniel, I don't like to use the 'Greek way out': knowledge beginns by knowing to not know. My point is much more simpler. If you know that you are ignorant about something you should ask questions and not bother about your own 'knowledge status'. Because I got the impression that we are free to choose where we want the least distortion on the record radius, irrespective of the tonearm kind or lenght (aka 'zero points') I thought that
the tonearm design and its 'own geometry' is, say, a 'different animal'. I still remember this issue about the 'optimal effective lenght' of the FR-64S. Was Ikeda san wrong, the user manual or who or what? In the same article by Kessler/Pisha I read: by the overhang of 15mm the only effective lenght that will be optimal is 274 mm, a lenght larger than many TT bases can accommodate. The authors also refer to Bauer and Seagrave (56/57) and not only to Bearwald btw. I have no idea when first stereo LP
was produced but assume, after reading you contribution, that their basic premise was Bearwald from 1941. And then to think , as I deed, that after my high school I was liberated from math. for the rest of my life.

Kind regards,

Dear Nandric, In regards to your post of 08-10-11, I think that the maker of the tonearm, by selecting the offset angle of the headshell and by selecting an upper and lower limit for effective length (the margins for this being equal to the length of the parallel slots in the headshell that permit fore and aft movement of the cartridge), has pari passu selected for us an optimal geometry. We (the end user) are largely denied the luxury of deciding for ourselves where we want our null points with respect to innermost vs outermost grooves. Unless of course one wants to put up with distortions created by forcing an inappropriate geometry to be made to "work". In my experience of N=1 it is best to go with the tonearm designer.