Hi Guys;
I've had the same problem for ages. upgraded shedloads of hardware and went through 3 versions of windows.
after so much fiddling;
it turned out to be the onboard sound hardware. AC97/realtek HD audio. I disabled it in setup and I havent had a single stutter since. I have some old wireless headphones with a usb soundcard and they work fine, with no stuttering.
hope this works for you. I tried all the other solutions out there and none worked. overclocking, voltage ramping, new hdds etc etc.