Turntables need a boost/equalizer to use regular line level inputs like your Lepai has (older pre amps and amps had a special "phono" circuit to accomplish this whereas a lot of newer gear no longer provides for this, your turntable has that preamp phono built in for that reason). If you can't hear the player connected via the rca inputs by selecting the appropriate mode there likely is a problem with the Lepai, since you have output from the tt with your active speakers. How about just for the heck of it trying another source like your phone or cd player with the Lepai?