I have finally switched the preamp in my BB605 to a Delano. Now, it is passive/active (volume push/pull) and has bass, treble, mids, mid switch to select the frequency, blend and a passive tone. I can only say "wow". I'm still in love with my BB735, but the 605 will be played more often than before. I'm not sure about the pickups. They are not too bad, but this bass may improve a lot.