Headphone volume aside, the DACs in computer soundcards and laptops can be quite variable in quality, so it's worth considering an external DAC. I know people in this forum like to bang on about DACs being a "mature technology", but that's only relevant if that technology is implemented in the device in question.

Raspberry Pi running Squeezelite->IQAudio Pi-DAC->NAD C320BEE amp->Usher S-520 bookshelf speakers