I was also experiencing a "hum" with the biktronics amp set up. I originally started with the stock radio and now have gone to an Alpine unit. Found it did not matter which radio I used, I had the humming. After some trial and error, I found that the only way to get rid of the hum was to have radio and amp grounded to the EXACT same spot. In my case I used a frame ground spot next to steering. When I initially discovered the need to have them ground in exact same spot, I had run jumpers from the radio and amp to the battery negative. I ws just was lazy and did not want to pull tank to route wires so I used ground by steering instead. Moral to the story is to take radio, amps and lighting and get them all ground to the same spot and see if humming disappears.