is your bass active? I would change the batteries right away if it is. I would also change your strings and get rid of the sansamp for now too. Clean up your signal chain and work on your left and right hand technique.
Tone comes predominantly from your fingers and not from your gear. Have all the EQ either bypassed or set to completely flat, and start from the beginning with our tone. Work on simple exercises that build your basic technique and that give you the freedom to concentrate on your sound and your time.
I have a set of video lesson podcasts that cover all of these aspects of playing -
http://gwizmon.podbean.com/2010/12/0...tice-routines/
Subscribe here -
http://janekgwizdala.com/Home.html
Janek