Perfect.  I think I'll go with the E10K then.  Thanks for your help!

    Thanks for the info.  The HD558s are relatively low impedance (at 50ohms), so it sounds like the DAC/amp might be the way to go.  I don't really mind having to unplug my headphones as I play to store them elsewhere anyway. 

  Understood.  While my PC is going to be the main outlet, I plan on using the headphones on multiple devices so this is definitely a factor in my decision.    Out of these two options would you say one is better than the other in terms of sound quality?  Or because of my admittedly entry...

These are both good advice, thank you! I'm going to do more research and decide between them.

I currently have the Dayton B652 and LP2020A+ speaker setup for my computer.  These are great for me (for now) and I still want to be able to use them for listening while not sitting at my desk.  I also have been wanting a pair of good headphones for both gaming and listening to music.    I am...