This adapter allows you to connect "normal" electret-type microphones to differential, phantom-powered inputs, like the ones to be found on sound mixing desks. I got one of those, but as the pinout was not mentioned anywhere, I made these photographs.
http://www.audixusa.com/docs_12/units/APS910.shtml
Mini-XLR pinout is supposed to be: 1: GND, 2: Signal, 3: Vbias. Even though the supply pin (3) is quite susceptible to noise coupling into the adapter output, Firther more, the signal pin (2) itself has a 1k or so pullup to Vbias. So to connect to a 2-pin electret microphone, just connect only pin 2. If you need more bias current, also connect pin 3, but then your signal will be slightly attenuated.
Phantom supply current is preetty high, at around 5mA each on "Hot" and "Cold" pins. (P48 on my mixing desk goes down to 13V when the adapter is connected)