"The unit sounds best when not using an external dac, most of the time, because there is no need for the added cables, complexity and longer signal paths."
>>>>I totally concur. In my particular case I’ve been able to eliminate the external DAC, AC power and AC Ground, power cords, interconnects, transformers, big honking capacitors, speaker cables, fuses. All of which obviously introduce noise and distortion to the sound. Also eliminated in one swell foop with small portable battery powered headphone system are requirements for the usual room acoustics devices, only the ones that operate outside the conventional modes are needed. You know....
These rather severe measures allow me to get down to the real nitty gritty.