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With me the issue is the power brick from the laptop. When the laptop is powered by the brick I hear a LOT of spurious electronic radiation.


I have the same problem with my HP.

A lot of modern notebook power supplies have a 3 wire connection to the notebook - look for a centre pin, outer cylindrical contact and on the inside of the outer contact there's another cylindrical contact. These are +'ve, -'ve and ground (or earth), with the outer contact being the ground. This introduces a mains ground (connected via the power supply) into the notebook.

Hence, ground (or earth) loop. A ground lift on the audio side may resolve this for you, but I'm not sure I'd do a ground lift on the mains connection to the power supply as doing so would defeat the saftey aspect of its presence. Technically speaking, the power supplies are NOT double insulated.

--=-- My credo: If it's worth doing, it's worth overdoing - just ask my missus, she'll tell ya laugh --=--
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