It's a straight connection to the barrel jack almost, it goes through an inductor but that won't affect you I think.
The jack on on the schematic between the two USB ports.
EDIT: The PCB traces may be a limitation current wise, I've not looked at them.
Actually the limit is most likely the series polarity protection diode wired between the power connector's positive contact and the input to the on-board +5vdc voltage divider. That diode has a 1 amp max continuous rated diode as I recall.