Yo wiskyman...I know just what your talking about with the bass signal, we tried recording for quite a while with just bass/direct box/comp/ and never seemed to get the right signal going on until I bought a art tube mp, and then we had a very good signal to work with, really got rid of that "swelling back-n-forth" sound as you say, but dont take my word for it ask Mr. sonusman, He be the man to ask!