I got a nice little $160 gadget, an Audioengine D1 USB DAC/headphone amp. It's just a tiny box with a loudness control and headphone/powered speaker output in the front and a USB input, stereo output jacks on the back. It takes the computer's DAC out of the loop and substitutes its own. I really like this gadget. Using the same headphones the sound coming from the computer is much improved, for iTunes, Cds and everything else. I will have to try some hi-res files; it can handle them too. You probably don't realize how crappy the sound chip and amp combination is on your computer, but this gadget will make that clear. It worked first time I plugged it into my Mac. I just went to Preferences and picked the box rather than the regular sound output. You can either plug the speakers into the D1 or continue to use them plugged into the computer.