I received a brand new Ibanez SR655E yesterday and there seems to be a problem with the preamp. Everything seems to work as expected except for the midrange knob. If I boost the midrange, it gets distorted; if I cut the midrange, the signal cuts out completely. The position of the mid frequency switch does not appear to have any impact on the problem. I've replaced the battery and tried different cables, but the problem persists. Has anyone else had this problem? Any recommendations about how to fix it? I'm a little bummed out because the bass is brand new ordered directly from Ibanez.