Fido:
I had also been looking at the Ortofon 2M black but then I read a post that said this cartridge is not a good match with the Rega tomearm.
If you check the
tonearm chart for the Rega RB300, you'll see that it shows 8-11 Hz as the "good" range. The Ortofon 2M Black weighs 7.2g and you can figure about .5g for mounting screws. Its compliance is 22.
So if you look at the Resonant Frequency Evaluator, you'll see that an RB300 with 8g worth of cartridge and hardware, with a compliance of 22 (10-6 cm/Dyne) comes in just at 8Hz, which is theoretically in the "safe" zone.
Audiofeil, an experienced dealer and A-gon poster, places the ideal resonant frequency at 10 Hz, but that doesn't necessarily mean that 8 Hz is "bad." He did state that 7.23 Hz (which it would be on a Technics arm) would be too low. It looks like the 11.5g effective mass of the RB 300 is at the upper limit, and lighter arms such as the Hadcock and VPI JWM9 would line up with a 9-10Hz resonant frequency.
It's my understanding that the VPI JMW9 arm is compatible with the Rega armboard.