Tommy Tempest
Power User
I'm not sure if what I found is standard on all the AXE FX III units sold, but I always had this underlying hum that never went away, no matter if a cable was plugged in or not. I could never find where it was coming from.
I just installed the latest firmware 1.09 beta and was checking out the new features and came across the AC line frequency under global settings. It was defaulted to 50hz. Since my U.S. standard frequency is 60hz, I immediately switched it to 60hz. Boom, the infamous underlying hum was gone. To test I put it back to 50hz and it was back.
So if you are in the U.S., and you find your AC line frequency default is set to 50hz, switch it to 60hz.
I just installed the latest firmware 1.09 beta and was checking out the new features and came across the AC line frequency under global settings. It was defaulted to 50hz. Since my U.S. standard frequency is 60hz, I immediately switched it to 60hz. Boom, the infamous underlying hum was gone. To test I put it back to 50hz and it was back.
So if you are in the U.S., and you find your AC line frequency default is set to 50hz, switch it to 60hz.