Something we don’t see discussed lately is tip mass and how responsive a cartridge is. Now what about these ruby and diamond cantilevers and what the effects of these cantilevers are? The diamond is still mounted to the cantilver with an epoxy, so it is not like the Sony of yore where it was a solid cantilever/diamond piece. Yes the cantilever should be stiffer with them gemstone, but what about at the cost of tip mass and how responsive it is? Secondly how well does the material damp resonances? It seems that in some respects that boron and compsoite materials might have an advantage here.
Has this come up in discussion recently? And have any conclusions been drawn?
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.
The higher mass of the diamond cantilever relative to the stylus was one explanation, or perhaps I should say speculation, as to why the early applications by Ortofon, e.g. in the Anna, reportedly resulted in slightly reduced trackability. I have no experience with the Anna, but having owned an MC Diamond for 6 weeks I can say it tracks like champ, every bit as well as the boron-cantilevered A90 with the same Replicant stylus. It’s also the quietest in the groove of any cartridge I’ve owned, for what that’s worth in this discussion. I believe Ortofon upgraded the suspension in the MC Diamond. Perhaps that’s a nod to the ramifications of the diamond cantilever but I really don’t know.
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.
I though they had stated up again. wasn't the London Reference the new version? I could be incorrect.
My friend is a huge collector of London Decca's he must have a doz or so. very nice sounding cart's, I agree. He has a very interesting system comprised of stacked quads. the carts sound very nice on those.
The Audio Technica AT-MC2022 was only manufactured in very limited quantities and has been sold out for years. The DS Audio Grand Master Extreme cartridge uses the same one piece cantilever/stylus but retails for $22,500.
My Koetsu DC was said to be one-piece, but a photomicrograph seems to show otherwise. In any case, there is no glob of epoxy to be seen - in fact, no evidence of epoxy at all. So, very low mass at the stylus.
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.
The new owner of the London Decca name has told me he hopes to restart production of the Reference and to offer a new version. He had suggested they would be available in August of this year.
It is cheating, in a way, to include Deccas in this discussion, being tip-sensing cartridges with just a couple of millimeters of the end of the armature effectively acting as the cantilever. All the other moving iron designs (eg Grado, SS, Nagaoka) are quite different, though I would be fascinated to learn how the mass of stylus/cantilever/moving iron compares to the stylus/cantilever/magnet or stylus/cantilever/coils of more common MM and MC designs. Is the cantilever assembly of a Hyperion lighter than that of a high end MC cartridge? I don't know, but I'd be interested to find out.
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