Just bought a Yamaha BB414 passive, PJ configuration, V-T with pup select/blend switch. It's got a hum. Controls don't affect it. Touching strings, bridge, jack doesn't affect it. Wiring cavity is FULL of LONG wires! Many could be shortened. Cable and amp are noiseless with my other passive bass. I'm thinking this may be my initiation into shielding that I have been trying to avoid for a long time. Unless you have another solution! Thanks.