you need to have a VPI or better TT to just get decent vinyl soundAFAIK yr TT AND yr cartridge, both, are fine. You SHOULD be enjoying good sound -- at least, I've heard the TT and found it great.
Check all the cartridge connections; borrow another phono just in case yr Bellari has a problem s/where.
You don't need a new ANYTHING just yet. By the looks of it, you haven't heard what yr vinyl sounds like yet.