what makes me wonder is, how all virtuosos can be hum-free? i have an old 90's Fernandes guitar which has noise-pickups. it is HSS and still i couldn't find solution possibilities for this until couple hours ago. this is what i got so far in searching the hum problem for my guitar Fernandes FR-55. it's been over a year ago and finally i got the closest possible solution on this. at very first i thought it was the circuitry. so i learn about soldering the components and find out what caused the hum. as far as i could get before the next one is 60Hz cycle hum. It's called "60 Hz cycle hum" because it's a signal that oscillates at 60 Hertz - sixty cycles a second. too complicated, why is it audible, since 60 Hz is so low in frequency range? here's why. we can hear it because it cycles, its harmonic notes is what we heard. 60, 120, 240, 480, 960, 1920, 3840, 7680, 15360, 30720,.. there we can hear them all ringing loudly. creating ground loop is the ve...