My Almond+ is plugged into a Belkin Battery Backup unit that provides 12v with a max of 3A. No problems ever and it even makes it semi-portable although that has only come in use twice.
The original power supply has a 2.5mm barrel plug with + center (pretty standard). It states 12v @ 2.5A. So a POE splitter that matches that size and power capacity should work. I do not want to shut my network down right now to try myself... Sorry.