Have got an ampeg BA110 practice amp but ever since I've had it it has a hum ( earth type sound). She plays fine just shouldn't have that hum. I Would send it back but I ordered a BA108 and they sent a BA110 by mistake (not complaining) just want to know if there's a cure for the humming noise (not feedback- hums when no inputs in play). Tried different kettle leads - no change. Anybody got any ideas. Cheers sparty..