of course you need a preamp- what are you using now?

i'm using...

right now i don't have a preamp..i am just running the mic through a mackie VLZ mixer and then into a m-audio mobilepre that is connected to my computer

So in reality you are running your mic through 2 preamps? This seems pretty counterintuitive to me...and it could be this signal path that is resulting in the undesirable sound. The two gain stages combined I'm sure can result in a louder noise floor. Try taking one of the two preamps out of the signal path completely.