I just bought a Yamaha BB 615 and I think it's a great bass for the money I payed. The bass has a preamp that is not bypass'able and that to me seem to be the only real bad thing about this bass. The bass, mid and treble cut/boost knobs on my bass seems to work more like cut/boost switches but with a knob. That is, when you turn them nothing happens the first 75% and then there's a drastic change of boost or cut right at the end. Is this the way it's suppose to function? Any BB614/615 owners out there that recognizes this problem... if it's a problem?