Will a DAC help with this setup?

[spat55]

Atm I have Diamond 9.1s with a Onkyo A-9030 and a SW 150 Sub (Which I haven't used yet) but have a Asus Xonar DG for audio from PC, will a DAC be much better? ATM the audio does seem a bit crackly, or when up higher when nothing is playing I can hear buzzing, more than likely the sound card right?

 

[spat55]

Anybody?

 

[spat55]

Another bump, need to know because I am thinking of sending it back.

 

[americanaudiophile]

An outboard DAC will be better. Most of them connect with USB so the soundcard or mobo doesn't matter. You have many to choose from. Try to find one from a company that has some audiophile credibility such as Cambridge Audio, M2Tech, or Teac Reference.
If the crackling happens during loud parts of the music regardless of how low you have the volume on the Onkyo then you are overloading the input. Turn the volume down on the PC. The buzzing noise may be a ground loop between the PC and Onkyo.
You can solve this by using a ground lifter on the Onkyo if it has a 3 prong AC cord or
an isolating transformer between the Onkyo and PC.
http://www.markertek.com/Audio-Equipment/Audio-Interface/Ground-Lift-Accessories/Calrad-Electronics/10-78-RCA.xhtml
Lots of info on this type of problem here:
http://www.jensen-transformers.com/