recording issue

[tek_]

hi, maybe stupid question but when I record my virus and MS2000 I notice some noise in the background wich is audible "sometimes" in my mix, so I have to ad some little cutoff to reduce it..on the sound infected ,I dont want to do a noise reduction cuz that will spoil quality to much on some sounds..,my question : with a better soundcard could this be solved? for now I have a revolution 7.1 m-audio wich is cheap but decent..I do record as high as possible tough.

thanks