A pre-amp for an old Roland 5?

I have an old Roland 5 which I have never really exercised (had it attached for a while to a B&O 5500 which didn't have enough of a pre-amp to exercise the Roland so I disconnected it). Now I would like to build a system around the Roland. I listen to all kinds of music, have a pair of Magneplanar IIIa speakers, which I might or might not replace. Any suggestions would be welcome.

Thanks.

JJB