If "the internet" can make a single-point arm work, a mag-lev arm can work. Don't listen to the internet.
The MA-505 is tough to beat and drops in place of the 303. Between the Rega arm and the 505, it's not terribly easy to exceed that performance, though many will disagree with that (and that's fine). The "X" suffix arm uses a fully shielded coaxial cable for the cartridge. The "S" suffix arm has silver wire. The 707 has adjustable effective mass that I initially found attractive, but it is accomplished by sliding a weight up and down the arm tube, essentially creating two higher frequency nodes in place of a single lower one. I wasn't sold on this idea's implementation enough to chase it, but they tend to be less expensive than the 505 if you wanted to test the waters.
The big "thing" with my arm design is the length. It is well known (simple geometry) that tracking distortion drops with length increase. But effective mass goes up with length, and also stiffness goes down with length. Both tend to be bad actors for a "universal" arm- one that is not suited to a single type of cartridge (high or low compliance). No free lunch as the saying goes.
Therefore, the challenge is a long, stiff acoustically inert arm tube that doesn't weigh four pounds. The tensioned cable idea looks interesting, but every length of cable between nodes (attachment points/breakover points) is resonant at a frequency. But it can provide a light and stiff structure. So really, the arm should be designed around the desired cartridge. The technology is so old, and we have the internet to draw upon to see if a desired arm/cartridge pairing had ever been done. Like the Benz-Micro silver on the Rega arm. That's what I ran for a long time, but I had to get there... I don't know it was done before I did it and further, I did not use the Rega alignment, I used Baerwald which has the cartridge "twisted" relative to the head shell. Just the way it is. Then "quality time" with test records to refine it from there for anti-skate force.
Material selection and implementation, and novel design all must come together as one. You must draw on multiple disciplines simultaneously or go through many premeditations to get to the end (which is never "the end"). I don't have time to continue down the path I started; I don't have funding to hire a patent attorney to draw up a disclosure and present it to the patent office, so it will remain "trade secret" until that situation changes, if ever.
On my BL-91 I run the 505X-II arm with the correct "X" head shells and either the V15-III or V15-V cartridge. The V15 line and the 505 are a match (possibly) made for each other. Really quite stunning. I do want to give the B-M Silver a whirl on there and I have a spare head shell available...
