This is a known issue using some interfaces the Laptops power
supply (beyond our control) uses a 3 pin plug. The Laptop only takes 2 conductors meaning the ground is drained through the unit itself the noise is picked up through interfaces manufactures that do not provide a solution
for this and there are a number of them. The easy solution the one we have taken for the M-Boxes that works with lots of other interfaces is to get a
power chord that can adapt form three pins to two pins eliminating the ground also a ground lifting device could be used I just bought a cheap extension chord that allow a 3 pin to be plugged into a 2 pin.
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