There is a port that takes XLR -or- 1/4".
I found some information that helped. The ambient mics use 'plug-in' power, which is about 5 volts. (XLR uses 48V phantom power.) So I had to buy an adaptor that not only changed 3.5mm to XLR, but also converts 48V to 5V. (Not sure if I can DIY-make...