I just got a new 13" Macbook 5 days ago (tasty I might add), and yesterday I finally got around to calibrating the battery. This uncovered a nasty little problem with the magsafe. When the machine is off/asleep it charges up like it should, but as soon as it is on the power brick starts making all sorts of crackling/buzzing noises that seem to parallel the CPU. Its as if the power brick is amplifying the CPU whine. The noise seems to get much better once the battery is charged. I should also mention that it gets nearly as hot as the CPU as well. I called Apple and they immediately agreed to send me a new one overnight, no questions asked. The apple discussion boards have many threads about this issue, but one question seems to remain: Does the problem really stem from the power supply, is it the macbook that is causing the problem, or some combination of both? I ask because I can still return it, but I would rather not since I have already donated my old 15" Albook to my brother and I've finally finished getting the Macbook setup to my liking. Has anyone else had and fixed this problem, and if so was it as simple as a new power adapter? Update: I actually got my new one, and while there is still a slight buzz it is significantly better. I compared mine to a friend's setup (he also has a 13" MacBook) and they are comparable in noise emissions. As far as the heat goes it is unquestionably better. I think these machines just draw a lot of power when they are charging and running. Anyone else having visions of the old Pismo chargers?