I am almost at the limit of my technical knowledge, but be aware that some of the cheaper XLR to mini jack adapters do have some functionality missing.

An XLR (or should that be A XLR???) plug has three connectors as part of a balanced system. A mono 3.5 jack only has two and is unbalanced (or sometimes floating). An expensive convertor will have a transformer or electronics to convert between balance and unbalanced, a cheaper one will join some wires together. You wil find that usually/often "joining some wires together" will be satisfactory. But sometimes you will get interferance that you can't identify.

Additionally, when using the "join some wire together" option, the engineers at work often add a small capacitor in the XLR, this is because some domestic kit (mini discs particularly) put 1.5 volts into the mic cable to power electret mics. We use Dynamic mics and they sometimes object to this voltage and hum. The capacitor cuts it out. If you have a cheap convertor a dynamic mic and hum, you may need to add a capacitor! (Or buy a better convertor).

John