first i just wanna say you have a great voice for radio.
what are you plugged into...a wall outlet or a surge protector? if your computer and amp are plugged into the same source that may have something to do with it. also check your cables and make sure one of them ain't going bad. just the other day..and i posted that i thought my interface was going bad and i was already to throw it in the trash when i decided to check the chain and it happened to be my mic when bad. so i would check the chain real close and you will find the issue. with that said i feel that it is your power supply.