Unclear, although the headphone output might be among other things lower in level. Now, I certainly use the digital output from the USB port of my computer when listening to music sources, but it has nothing to do with the quality of the computer DAC. A cleaner signal results when the output is digital rather than having been converted to analog and subjected to the noisy environment in a computer. The DAC chip in the Xitel HiFi Link which takes the USB output and converts it is a basic quality chip which I'm certain would cost less than a dollar each in manufacturer quantities.
