The DAC (Digital/Analog Conversion) component isn't going to make any audible difference. The 32 ohm DT770s still aren't super efficient (impedance alone means nothing) and I have found some devices that can not drive them to adequate listening levels. If you find yourself turning all your digital volumes up most of the way for sensible levels, an external amp or DAC/Amp combo might yield benefits. The big win would be the convenience of an analog volume knob and jack on top of your desk.