help with harshness / brightness - cary 303-100

I'm really new to audio. I've just set up my first system. Its: plinius 82000 int. amp, well tempered classic TT with upgraded arm and platter, cary 303/100 cdp, energery veritas 2.3 speakers. I just added the turntable last night and the entire system sounds great. I am now wondering if I have a problem with my cd player fitting into my system or if there is a cable tweek that can help. The harshness that is present really makes me turn the volume down and after a short listening session ... loose interest and leave the room. I'm currently using the reference 2 monster cable for interconnects and monstercable 12 gauge flat wire for my speaker cables. I'm ready to purchase cables ... is there a cure? Or should I try another player for my system that is less bright? Room treatments?