A Copernican View of the Turntable System

Yes. Love my DV505 so much that I have two of them. And then on top of that a dear friend (my longest term audiophile friend) gave me his DV501 last year. The DV501 was introduced shortly after the DV505. It is very like the 505 except that it lacks a few doodads, so it could be marketed for a lower price. DV501 uses counter-weight balance instead of dynamic balance, lacks the little spring-loaded resonance-reducing gizmo that is tucked up under the horizontally pivoting part of the 505 and 507. Some liked it better than the DV505. I preferred DV505 to 507 because the 505 can be surface-mounted; you don't have to drill a hole in your armboard or plinth to accommodate a vertical shaft that goes below the top surface of one or the other. When I built my early slate plinths, I decided to limit myself to surface-mount tonearms so as not to have to implement removable arm boards. The fully developed Mk3 plinth does have a removable slate or alu armboard, however, can use any tonearm of 10 or more inches effective length.

Dear Nandric, dear Lewm, the japanese tonearm engineers of the 1970ies and 1980ies did not at all sign up to the Baerwald tangential curve.
At least not the majority of them.
And for some good reason.
They realized pretty early, that the situation for a stereo stylus is different and that the decreasing groove radius towards the inner label becomes more and more difficult.
Thus we see a lot of classic japanese tonearms with geometries pointing more toward Stevenson and in general more toward DIN-standard then IEC.
I won't say it is "better", but I would say that there are good reasons for not following the way of the "average lowest distortion".
Having an eye of where the maxima and minima of the derivation from tangential zero error are in fact located can bring interesting results.
In the western audio hemisphere it was/is - in general - all Baerwald/Loefgren A (with very little Loefgren B ..).
The fact that Loefgren A/Baerwald was calculated when no one dreamed yet about a stereo stylus is seldom mentioned today.
There are calculations which can indeed give lower average distortion as Baerwald - especially when tracking a stereo groove.
Cheers,
D.

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".