I am modifying an old bass and i replaced the bridge with a piezo. the bridge is on its own output - so all of the electronics will be separate from the magnetic pickups (which are passive anyway). my question is, can i simply hook the bridge up to a preamp by itself, without any other mag pickups? would i need a magnetic buffer? and would the volume and tone pots connected to the preamp affect the piezo? thank you for any help with this.