Bram, you need to explain more clearly what you are trying to do. Do you mean "bi-wire" rather than "bi-amp?" Bi-wire means running two different speaker wires from your amp to your speakers, one for the bass and one for the upper frequencies. If so, you would be using speaker connectors (not rca) and a speaker wire that is designed as a bi-wire cable (meaning it has two leads at one end and four leads at the other end. I imagine you can create your own bi-wire cable by joining the ends of two leads at one end and having the other ends separate (ultimately creating a speaker cable that is one long y-adapter). I don't know how much benefit you will really see from this, though. I have done it before and didn't notice any real difference.
Bi-amp means running each speaker off of two different amps, which means you would have two cables for each channel coming from your preamp to two different amps. If you only have one set of outputs on your preamp, you would then use a y-connector (rca cable) to split the signal and send half to the amp that runs the bass and half to the amp that runs the upper frequencies. You would then have two separate speaker cables (from two separate amps) running to each speaker. I have done this also with the Martin Logans and noticed a huge positive difference in the quality of sound.