The pinout for the 25 pin line out connector on the Octopre can be found here. The line outputs are balanced so you will need to ensure that the 25 pin connector is wired correctly if you intend to route the outputs to an unbalanced system. If you want to wire unbalanced connectors to the other end then here's how (example for one channel):
Connect H pin to tip of connector
Connect C pin to sleeve of connector
Connect G pin to cable shield
Note that the Octopre can accept balanced or unbalanced signals at the line input.