Greetings, I am looking for help with a Warwick Corvette STD 2008 passive 5 string Just a couple of weeks ago a strange hum noise like a single coil hum started happening. Now it is so bad that it will cause feed back when any amp is at higher volumes, band playing volumes. The hum goes away when then tone is rolled off all the way. Looked at the electronics and nothing appears visually out of place. Physically all the connections are fine. The hum noise is there for all three neck, both or bridge pick up selection (single coil Jazz type). I was thinking a grounding issue but that usually goes away if you touch the strings or the wires inside the cavity but the noise is still there. Rolling off the tone you can hear the noise lessen the more bass it gets and less treble. Both pickups are just as responsive and loud as ever. No noticeable difference with either pickup. Anyone got an idea or have experienced this before?