Theory behind well tempered tonearm?

Bump!!

If you go to the Well Tempered Lab website you can read about it under the Blog section.
I have the Amadeus MKII and was skeptical about this before I heard it.

Thanks @sebrof 
I will read it over this weekend

I owned an original Well-Tempered Turntable many years ago and don’t really remember any shift of the arm fore and aft. The fluid in which the paddle (now, I guess a golfball?) was suspended was fairly viscous (thick) and acted as a damper as well as a substitute for more conventional bearings. The biggest issue was the amount of fluid used since that could change the sound. I had tricked out my table with a variety of mods, including a heavy brass clamp around the fluid cup, a more up-to-date motor, a different platter and perhaps some change to the arm wand (I don’t remember, it’s been quite a long time).
The table was a very good performer in the era of Linn at reasonable cost. It did not have the gravitas of more expensive, bigger tables I subsequently owned. I had a by then long in the tooth Technics SP-10 at the time I bought the Well-Tempered (in the mid-’80s?). Now the SP-10 has been restored and almost ready to use in my second system. The Well Tempered is long gone, but I had a positive ownership experience with it. I also used a range of different cartridges with it over the years it was in operation, all without issue.

@whart 
did you use a protractor to setup the cartridge? I am asking because my friend is having the Special Edition version (they only made 50 of them) and he told me he just mounted the cartridge onto the arm. No protractor needed since there is not any slot for adjustment for the overhang.
 Thanks 

@dangcaonguyen - don’t remember what tools came with the table, at that time, I was having help on turntable set up, particularly once I moved up in the cartridge world-- I had set up plenty of turntables in the early ’70s, but the Well-Tempered required someone familiar with it, and I got to the point where I was using fairly expensive cartridges (e.g. Lyra Parnassus was the last one on that table, I think), so can’t tell you more. Sorry. I was friendly with the fellow who was the US distributor for long while, but times change. Really haven’t kept up with the turntable or the company. At the time the arm and table were introduced, his work was considered ingenious, and it wasn’t crazy money.
Sorry I can’t provide more info. It’s been quite a while.

Thanks @whart 
I appreciate your response. Now I know for sure that the arm, cartridge still need to setup correctly to achieve the best performance. (Not just flush mounting like my friend suggested)

@dangcaonguyen - why not contact Well Tempered? Or a dealer within your locale that handles the table and provide further info?

Dang, You are right to wonder about the WT tonearm.  It is said to have no bearing and hence zero bearing friction.  But of course, it DOES have a bearing in the strict definition of the term; otherwise it could not pivot.  As you mentioned, the "bearing" is essentially a golf ball suspended in lots of goop.  In fairness, the well that confines the damping fluid affords only a very little tolerance for the golf ball to "wiggle", but without measuring it, I would guess that the tolerance exceeds that for any decent quality tonearm with captured bearings.  For me, the consequence of the design that irks me is my observation that the azimuth setting is not stable as the tonearm traverses the LP surface.  In addition, as you note, the headshell holes are not slotted, so the distance between the mounting holes in the cartridge body and the stylus tip had better be the standard value (which I don't recall), else the cartridge will be a bit out of line with whatever geometry WT had in mind. One reason why the tonearm can sound "good" to many people, in my opinion, is the heavy damping of tonearm motion in all directions, which may mask imperfect control of the cartridge body.  The extensive damping makes most LPs sound alike, in my experience.  All "good"; none "great" or exceptional.

All of the above observations are relevant to the WT Reference tonearm that was introduced in the 90s.  I heard it many times, mounted on a WT Reference TT, over a period of more than 10 years in the system of a close friend who owned a fine audio system.  The latest iterations of the WT tonearm, such as the one used on the Amadeus, may be free of most or all of the perceived issues. For sure, the Amadeus has many fans.

@whart 
Thanks, but it is not my turntable. I just curious about the Well Temperd tonearm geometry, but I will do some research.
@lewm 
Yes, I have been thinking the same thing. What my friend listening is not the best the cartridge can bring to the performance. Since the arm is heavy damp, it is masking both the good and bad. But I will do some more research.
Thank you all.