My Delta's [older "HDCD" version] display is dim all the time, and is actually preferable to a too-bright display favored by some manufacturers. It can really distract from the listening experience, esp. when you simply want to relax and enjoy the music without being stared down by your rig. Too bad CAL did not incorporate a dimmer in the first place, as did many other manufacturers. I use mine with a Sonic Frontiers jitterbug and Muse dac, and neither seems to impact the display. The fact that it occurs when your dac is on may be of more concern. Any player/transport worth its digits should have separate circuitry for its display, although I'm not sure how CAL set up the Delta. I would think it belongs in this category. If the display is legible and does not mess with the sound, perhaps it is best left alone. If it is bothersome, try a repair via Approved Audio Service 860-567-5801 or Just Service Inc. 773-871-7171. Good luck.