[xtcmojo16]

Hi all, 1st-time poster here. I hope you knowledgeable people can help me

 
Some background info:
I connect my Sennheiser hd25-i headphones through the front panel jack of my PC. I have on-board sound (Conexant HD Audio).
Electromagnetic interference is a known problem when using the front panel of on-board sound but it's never been a big problem for me until recently. Now, whenever I start a game that uses my graphics card (Radeon 7750), I get a horrible, loud buzzing sound. I have run diagnostic tests on the graphics, sound and USB ports to discount the possibility of faulty hardware, so I can only assume that this is due to electromagnetic interference from the graphics card.
 
 
1. I have read that one way to eliminate this kind of interference is to use USB DAC/amps. Is that correct?
2. I have also read that the sound quality can improve upon on-board sound. Is that correct? This review suggests otherwise:
lhttp://www.tomshardware.co.uk/high-end-pc-audio,review-32894-19.html
 
If USB DAC/amps can eliminate this buzzing I am looking for a sub $100 solution (best bang for buck) with a focus on getting a great sound out of my headphones (I may upgrade to HD600 at a later date). I don't care about 3D sound but I dabble with music production software (Reaper) so a clear sound with a flat frequency response is important to me (although I'm not an audiophile, am happy listening to 256kbps MP3s). 
 
Possible candidates are:
- Asus Xonar U3 Mobile USB (very cheap!)
- FiiO E10K
- Encore MDSD (Sonic Unity)
 
 
Any advice/suggestions would be appreciated. Thanks for reading!

 

[PurpleAngel]

FiiO E10K or FiiO Q1 or Schiit Fulla.
All three are USB-DAC-amps
 
Hifimediy sells DAC/headphone amplifiers, but know little about them.

 

[xtcmojo16]

Thanks PurpleAngel.
 
I was leaning heavily towards a Fiio E10k until I saw the Hifimediy product line....
 
Decisions, decisions.....!!!