The humming noise on lowest setting of one or both LED’s is indeed normal and every Scurion has it. In order to get such a super-low power level we need to pulse the current with a frequency that makes unfortunately one of the components of the electronics humming. There is no alternative and the problem is not so big fortunately. If you find yourself in a very quiet environment and if the humming is disturbing you can just set that LED on power level 2 and the humming is completely gone. B.t.w. also the strobing effect (if you look through a camera on the light) is gone then ;-)