For those owning the DS DAC Mk I (not sure about Mk II) reboot it from time to time, it can get stuck soundwise.
Take care that you didn’t change anything of or near your setup since the last good day.
Then there are bad ear or bad mood days, just as you sometimes don’t like your best whisky or are not in the mood to watch a great film.
Then there are bad power supply days for some, but this usually isn’t so much a question of magic or not (but it certainly can still cause worse sound). In my experience, regenerators if needed, can help a lot, but in such cases help basic technical sound characteristics like grip, dynamics, focus, soundstage, but not really so much the aspects of magic, airy, natural, realistic, organic sound.
The latter (the general quality of equipment ignored for a moment) in my experience is a matter of proper speaker placement, room situation and especially bass/sub setup. Things which usually don’t change.
What I can tell you is, although I don’t have more HF polluters than anyone else, I use several bigger and smaller active devices with small antennas for room and equipment related HF, RF and EMI cancelling, which make a total of 14 antennas in or near the equipment, speakers and room. Doesn’t look weird, most can hardly be seen, but when I remove them, the magic described above collapses from realism to hifi for me. This is still what most everyone else would listen to, but you can’t, if you heard the status before. The only sound coming close I heard anywhere at shows and similar is from the best horns with tube amps using double coke can like tubes and the like (which unfortunately don’t have the power and bass I like).
What I want to say is that the main destroyer of magic, realistic sound seems to be noise of any kind in equipment and room. You get more resolution, the less noise you have. Part of it is addressed by equipment design but more of it by other elimination efforts only. So if you have differences in your listening pleasure , it might not just be your mood or power cirquit, but maybe your different HF load situation, which can come from a ton of active or snoozing electrical stuff in your house, but also mobile’s, WiFi’s, microwave or some other environmental radiation.
Some will think about this as others years ago about cabling…I know .