There are the same number of phisical ports on the A400 and A800.
On the A400, they are single ports, with only one phone line per plug.
On the A800, each plug have two phone lines . One is carried out on the green/red wires, the second line is carried out on the yellow/black pair.
Take the line that come out from the Quintum to a Rj-11 block. Connect via wires to two diferent phone lines that way.
Or buy one of those plastic splitters on any electronic stores that open up the lines in two diferent circuits.