Help with uninspiring sound with my turntable.

Can anyone give me some suggestions what to do to improve my vinyl sound - I purchased a Wilson Benesch TT with their .05 arm and a Sumiko Celebration cartridge here on Audiogon. I have a Mac c500t pre-amp that is still breaking in . The sound quality is lac-luster, and particularly annoying is the vocals can sound "crunchy" and extremely edgy. I don't know how many hours the cartridge has on it. I have tried different loading impedance's - but something is so off I would really appreciate any ideas. I listen to Jazz and Rock albums mostly. Thanks for your input!