Graham Phantom Elite vs. AS Aquilar

@wrm57 First off, the Graham is an extremely well made arm and a good performer. It's singular problem is it's price. There are to many arms that are as good or better at 1/3rd the price. Having said that. Both Graham and Basis by virtue of their design changes admit that the basic unipivot concept is defective.

For a cartridge to perform at it's best the tonearm that it is mounted in can only have two degrees of freedom, vertical and horizontal. Unipivot arms have a third degree and that is rotationally around the tonearms long axis. Even if the arm/cartridge combination had the perfect geometry with the pivot point exactly at record level these arms are wobbly, difficult to manage and keep in adjustment. I would wager that cartridge accidents are higher with these arms. 

For the best performance the cartridge has to be held rigidly in the proper orientation over the record. The trend in modern arms as exemplified by the SAT arms, is very stiff, two axis bearing designs. Examples are the Schroder CB, Reed 2G, Kuzma 4 Point 9, the Tri planar, the Origin Live arms and the SME's. The Aquilar also is in this class but again the price is way too high for what you get. I personally do not like VTA towers. If you are jumping back and forth between cartridges that frequently you need two arms. If you are changing VTA all the time you need a tranquilizer. Set it at 93 degrees and forget it.  

What do you like, if you don't like VTA towers?  Do you like the inexact and treacherous process of finding the right VTA, holding the tonearm precisely in that selected position for dear life, and then searching for the tiny and usually weakly binding set screw which needs to be tightened down with a tool that is usually just out of your reach?  I personally hate that and would not have any tonearm that still relies on that primitive method for setting VTA.  There are a few vintage Japanese tonearms that permit setting VTA by a rotating knob, positioned over top of the vertical bearing as opposed to a side mounted tower, that moves the pivot up or down and can be fixed once a correct VTA is achieved, like the Victor 80XX series and the Technics B500 (and maybe the 100), but after that the VTA tower is the best solution in my opinion.

I’m with lewm on this one. Way back when, I had an OL-modded Rega arm that set VTA with a grub screw on the shaft. I couldn’t run to a Graham 2.2 fast enough. VTA towers are a boon to sanity and civilization.

But the rotational stability of that Graham was indeed a detriment, one that the Phantom family’s magnetic stabilization largely, if not completely, overcame. Most other high-end unipivots have followed suit, including the pre-Tosca Durands and the Reed 3P, which is essentially a magnetically-stabilized unipivot, according to its lit. These arms perform a very high level using this "defective" bearing structure. But I do get mijo’s point, which is one reason I’m looking to go gimbal, or "gimbalesque," like the 4Points, with my next arm. I have a couple of gimbaled Ortofons (read, Jelcos) that perform surprisingly well but they are not in the league of my Phantom Supreme or III.

And I recognize the drawbacks of VTA towers. More superstructure to resonate, more mechanisms to introduce error and perhaps instability. What do you think of the Tosca’s innovative "spare-tire-jack" approach? Looks like either an ingenious solution or a big problem, I can’t tell which. I’d like to see one in action.

Durand Tosca

From my observation of a Tosca, it seemed to use an outrigger contraption, a metal peg that sticks out from the pivot point toward the spindle side.  That peg rides on a horizontal support strut set at a right angle to the peg, so as to keep the unipivot from rotating, at least to that one side.  I recall thinking that arrangement was not satisfying, given the cost factor of a Tosca.  The metal on metal contact would seem potentially to create noise AND drag on the horizontal travel of the arm wand. But perhaps my idea of what is going on is incorrect.

Lewm, I think you're thinking of the Telos, no longer made, which constrained the unipivot with that little bar, as you described. The Tosca is the newest Durand arm, and its first gimbal design. It has this unusual VTA adjustment that places the entire bearing assembly atop a kind of scissor jack. Weird but interesting.