M17x R1 recording hum/buzz

Hey forum, I've recently decided to make a song, which i record into the computer using the mic jack connected to my amp via a 9mm cable.
Theres only one problem.. I have a really bad buzz / hum that is present. It makes everything sound yuck and cheap.
Is there anyway to get rid of this? par using another computer?
my countries voltage is 240V, which I hear is part of it.
turning off the 260m's does not eliminate this noise.
Nor does disconnecting from the wall.

 

The mic in the M17X R2 is bad for professional usage. I use a Logitech Desktop Microphone and my voice sounds crystal clear.

 

Well, I think his problem is related to directly plugging in the 9mm cable from his amp's output into the microphone-in port of the laptop.

Munkeynz, perhaps your gain or input settings are too high. I don't know if I'm getting my terminologies right, but I hope you get the idea. I used to have that issue when the mic-in on the computer's end was too high.

In Windows 7/Vista, there's a way to change the level of the Microphone Array and Microphone Boost. Try to experiment with those two level-bars and see if you can achieve some improvement.