td-01 chinese tonearm?

I think the ball would have to be solidly in the receiver for this tonearm to work at all, with the weight of the tonearm holding it in place like any other unipivot, otherwise it would be swinging around all over the place. Armstrod is right that there cant be more than a drop or two of oil in there, not like a well tempered that has an fluid bath. And the only way to adjust asimuth would be by turning the counterweight and locking it off center. there must be a way to adjust the lenght of the string so it is tight, but allows the arm to sit firmly in the cup.

By the way, does anyone remember a system that used 3 ball bearings on the bottom in a triangle with one ball bearing in the arm sitting in the middle in a kind of unipivot arrangement that was much more stable than your usual pinpoint pivot?

Manitunc: "By the way, does anyone remember a system that used 3 ball bearings on the bottom in a triangle with one ball bearing in the arm sitting in the middle in a kind of unipivot arrangement that was much more stable than your usual pinpoint pivot?"

I believe you're talking about the Hadcock tonearm. Here's an excerpt from a review in 6moons:

"So, with a blast of trumpets, let's now unveil the £689 Hadcock 242SE. It looks like a conventional unipivot, except it's not. The needle point isn't so much a needle as an elongated cone tip. The cup isn't a cup at all because it holds four tiny brass balls to act as a bearing. So it's a compromise, really - a semi unipivot, its scale reduced to virtually act as a unipivot while producing the greater stability inherent in a dual-pivot design. Very clever, you say - but does it work? Let's find out."

Here's a picture.

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Nope, thats not it. I have a Hadcock and its not what I am thinking of. Maybe a Helius or a Basis Vector. 3 balls creating a triangle, with a 4th ball in the center and raised above the other 3. Maybe I just thought of it?

I think it was the Helius Orion first & the Cyalene later using the 3+1 balls.
I recall some similarities with the old monophonic "Gray" arm that uses grease (instead of oil in the TD-01)
Another thing that differentiates the WT is the great mass at the pivot point.

I think the arm Manitunc referred to was the Wilson Benesch Act 0.5:

http://www.stereophile.com/content/wilson-benesch-full-circle-turntable-act-05-tonearm-ply-mc-cartridge-page-2