If a standard Fender (or Fender style) J Bass has three knobs, it has been my experience that- two control volume, one for each pick up one controls tone Understanding that both volume knobs have to be set at the same level to defeat hum... why not have just one knob to control the volume on both pickups? I always use both pickups. However, I understand that some players may not. I dont understand why they don't have a switch (three position: bridge, neck, both) instead of the knobs. Is there something I am missing? I am not going to rewire my bass over this... but I thought this might be interesting conversation.