I have an American Fender Jazz Bass, it's passive, whenever I turn up the bridge pick up all the way I hear a humming sound. Doesn't matter what amp I'm coming out of, even when I'm plugged directly into an interface to record, I'm having this issue. Any thoughts of what this could be?
Does the hum stop when you balance the volume of both pickups? If so, your single coil pickups are functioning properly. If not, does anything else impact the hum?
If you want to remove the hum when you favour one pickup, you'll need to drop in some humbuckers. You will lose some of your top end tone, even with the best humbuckers. The trade off may or may not be worth it to you. I don't like hum and like to favour my bridge pickup so all my basses have humbuckers.