I have been wanting to hook my pair of DSP3100's and play my Nord Stage Piano through them. The keyboard has regular 1/4" ouput jacks. Could I just run a cable that has 1/4" plug on one end and an RCA plug on the other and plug the RCA into the digital inputs on the back of the DSP's? Or would I need some kind of controller box in between them? I don't have any old Merdian signal processor kit laying around.

G68SL, G98DH, DSP5500, DSP5500HC, DSP3100, JL Audio F112 Sub, DirecTV, Sonos, 4 Revivers (Highend-Source)