I got anew phone recently, because my contract ended and I switched from provider.
This phone, another nokia, came with yet another smaller AC adaptor. So now I have 3 different type of adaptors, all working on my phone:
On the right: The old one, the weight suggests that it has a transformer inside (right word?).
In the middle: This one came with my E40, it feels (and sounds like) a switched power supply.
on the left: The latest with my new phone. (also switched).
While the middle and the left one are obviously superior. They weigh less and most likely have higher efficiency, I cannot use them. Like most switched power supply, the switching is audable.
While the middle one is doable, the newest (left) makes so much noise it annoys me even when I have music playing and my computer is running.
This is not a nokia problem at all, I am having the same issue with my DEC phone AC adaptor, universal laptop adaptor, acer netbook adaptor, etc. I know most people have ruin there hearing (in ear headphones, so loud the whole train compartment can enjoy the music (don’t tell STEMRA!!!)), but it annoys me terrible (and I have damaged my ears aswell) .