What's a good cartridge for infinity black widow?

This site has a formula that you may find useful: (http://www.theanalogdept.com/cartridge___arm_matching.htm)

Mr J- Which V15? The V15 series began in 1964, and there have been a plethora of variations since, with many differing compliances.

Actually- The weight of the cartridge is not what's important. The Black Widow is a VERY low effective mass arm, and needs a high-compliance cartridge. The Blue-Point(at 12x10-6cm/dyne) is considered a fairly low compliance cartridge. Here's a good treatise on compatibilty: (http://www.gcaudio.com/resources/howtos/tonearmcartridge.html) But then- That's science and physics, which don't ALWAYS apply when it comes to audio.

The chances of finding a Sonus Blue cartridge with a rubber compliance that wasn't hardened by now would be very slim. That's unfortunate as it would be ideal for the Black Widow arm(I had one in a Magnepan Unipivot I way back when). Replacement styli haven't been avaiable for those for a number of years either, Sonic Research having gone out of business long ago. Here's company that offers a variety of older cartridges: (http://www.adelcom.net/cartridge.htm)