Headphone:
Amplifier:
Soundcard:
USB or 1/8":
The static you hear is likely a ground issue though. More often than not, if you're using 3.5mm (1/8"), the problem is the cable itself. A lot of the times, 3 poles doesn't work, or 4 poles doesn't work, the difference inside the plug could literally be 1mm, and that could be what's causing it. Try using 3 pole 3.5mm and then a 4 pole 3.5mm cable.