Not sure about other DACs, but the DACmagic has both a USB input and TOSlink and coaxial digital inputs, switchable on the front panel. That at least provides the option of comparing the sound you get from a CD transport with what you get from USB.
If you haven't already, check out the Headroom website (www.headphone.com) for lots of great info on headphones and amps. In-ear 'phones like the Eytomic are great if you expect noisy surroundings, which seems pretty likely.
If you haven't already, check out the Headroom website (www.headphone.com) for lots of great info on headphones and amps. In-ear 'phones like the Eytomic are great if you expect noisy surroundings, which seems pretty likely.