Dimond Cantilevers And Tip Mass

I think this is a very good question.  Designers have adopted extraordinary measures to reduce the effective mass of the moving elements of a cartridge.  The primary advantage of moving coil over moving magnet is that the effective mass of coils is lower.  The coils are located close to the pivot point of the system, so any given amount of mass at that location has FAR less impact on the effective mass than the same amount of mass located at the tip of the cantilever.  Thus, the mass of the cantilever, particularly near the type, matters a lot.  That is why ultra light metals formed into a thin tube is employed.  This minimizes mass for any given stiffness of the assembly.  A solid diamond cantilever would maximize stiffness, but it would weight quite a lot even if the diameter is made quite small.  Unlike a tube, a solid rod does not maximize rigidity for any give mass.  The reason to use diamond is to have extreme rigidity and as little flexing or dissipation of the movement of the stylus as possible (all of the movement transferred to the generating element (coils or magnet).  You do NOT want the cantilever to do any kind of damping or any other alteration of the movement of the cantilever; the suspension located after the generating elements do that job.

I suspect that solid diamond cantilevers have higher effective mass, but, the extreme rigidity makes the tradeoff worth it to the designer.

Yes, AT claims the stylus and cantilever are from a single lab grown diamond.  That means no squishy adhesive to mar transmission of motion down the cantilever.  I have not heard this cartridge.  I would like to hear it and compare it with the ART1000 cartridge which has the coils attached extremely close to the stylus tip.  I've heard the ART1000 and it is a terrific sounding cartridge.  At almost twice the price, the MC2022 better be pretty good.

Also, the London Decca ang Garrot Bros. cartridges have a cantilever--it is just a funky bent thing that doesn't look like anyone else's cantilever.  

That was an interesting cartridge--very alive sounding and almost meeting my "pretty good" standard.

While theoretical discussions of the advantage of each type of cantilever can be interesting, in practical terms, even if cost/price is no object, the choice comes down to the sound, and that is dependent on how the choice of stylus, cantilever and the suspension work together.  Jonathan Carr, the designer of Lyra cartridge has talked about this and how boron, beryllium, diamond and "whiskered aluminum" (solid aluminum rod) cantilevers work well with different suspensions.  His personal preference was the whiskered aluminum with a particular suspension but that turned out to be impractical because the suspension would go out of tune too quickly.  

It becomes a particularly tricky question when it comes to a rebuild by anyone other than the original manufacturer.  What do they replace in a rebuild, and do they touch the suspension and if they do, what choice, if any, do they make for changing the suspension to fit the particular sound of the cartridge they are working on.