Problems with audio.

Ever since I build my PC a couple of months ago I have been having problems with my sound. The first problem I encountered was that I was unable to play sounds through my audiojack plugin. The Realtek Digital output over at Control Panel -> Sound does show activity however no sound is coming from my speakers.

As a solution I bought a usb headset, which manages to play the sound perfectly fine. However when I use the microphone part of the headset the sound I produce sounds very choppy. When I use the microphone on my older laptop the sound is fine, thus it is definitely a problem with my PC and not my headset.

I have tried to deinstall and reinstall my drivers a couple of times, but to no avail. The motherboard im using is an Asrock 970 Extreme4. My brother has the same build as me and has similar problems with audio jacks but no problems with his usb microphone. Help is very much appreciated.