i dont know why no one has said this yet. as you are standing (or sitting), slowly twist to the left or right and you will notice the hum gets better and worse. try to find the one position where there is the least amount of noise. if there is still a problem, try to adjust the settings on the amp to minimize the noise. i don't like using noise gates because i think they affect the tone too much and will sound less sharp, but sometimes its your only option. also turning the treble or presence down will help but also will negatively effect the tone. your tone is the most important thing, more important than getting rid of the noise completely, so make sure it sounds good because most times that noise will get buried in the mix or will add to the rawness of a performance which i think is also important. you can always chop off a section in your DAW where the guitar is not playing (which is really the only time the noise is noticable)