Before knowing as much as I needed to know, I put the proverbial cart before the horse a couple of years ago. I latched on to an SME 3009R still sealed in the original packaging. I’ve not taken it from the sealed wrapping, since I later thought I may need a lower mass arm for an MC cart, such as an AT Art 9.
Note: I just noticed I made a typo on the tonearm model I’m considering, though most of you already likely understood I must have meant SME M2-9R, at 9 g effective mass, and improved ball races, etc., vs. the early production 3009R at 12.5 g. effective mass with nylon bearing.
Hi @ nolojunko,
By the numbers, a 9-ish gram effective mass arm is a reasonably good match for your AT9 which is specified at a fairly high compliance for an MC of 18×10-6cm/dyne.
A large majority of current MC’s are in the 12-15 range and vintage ones can go down into the 6 range (very low compliance).
Numbers are just that however, and you’ll find (for example) that subtle changes in effective mass can significantly change the character of the cartridge.
I relate my experience with arms that have multiple counterweights (Durand, Tri-Planar, Moerch, Kuzma) which allow you to use lighter weight combinations (farther from the bearing pivot) or heavier ones (closer to the bearing pivot) to achieve the desired tracking force.
The actual change in effective mass is very subtle, but the audible change in presentation can be quite dramatic, depending on the cartridge.
Results from the few arms I’ve played with which have sliding weights along the arm tube yield even more significant results as you’d expect.
I think the bigger question for you relates to whether you’ll find yourself liking the AT cartridge. If you don’t for some reason, you may be locking yourself into fewer choices down the road - trying to source a high compliance MC to match your tonearm.
I like to think of cartridges as a consumable item (much as we don’t like to) and to approach this from the tonearm perspective - matching a cartridge to the tonearm rather than the other way around.
The safe bet (given the current range of cartridges) is to source an arm with an effective mass in the 11-12 gram range.
Having said that, none of this is an absolute, and I don’t mean to strike fear in your heart over the SME / AT combination.
Thom @ Galibier Design