I am looking for a pickup for my upright bass. I've never played upright through a pickup before..Someone had recommended the K&K brand to me and I was looking at the Bass Max. However...I learned that one of my favorite double bassists plays with the Fishman BP-100. I want the traditional double bass sound but also the warm tone that is present in more Rock oriented music. Also...Is it absolutely necessary to use the Fishman B-II preamp with the Fishman pickup for a DECENT sound?