We'll if you believe that cables change the sound (everyone is different, that's why I say this), then you might try a pure silver cable. That would be a pretty expensive recable, so I suggest you try some Silver-plated copper to see if you notice a change.
Alternatively, (again, if you believe in this) you could give your cable time to burn-in. Some people feel that the sound will change once the cables 'breaks-in'.
Thing is, if you find that the cable makes a difference, then you also might want to pay attention to what kinds of jacks you are using, the solder, and soldering technique (check that you dont have a cold joint).
These are merely suggestions. I honestly don't care who believes what or why. Take them as you will.