airules (Level 1)

The hum could be a mains cable interfering with it. Try using an earthed or balanced connection (like xlr or balanced 1/4 inch), and move all power cables well clear. Could also be the way it's connected. If it's plugged into a computer, sometimes the hum is the computers sound card configuration. My hp hums on the output if the power cables in but doesnt at all on just battery. ...