I don't intend to start a debate but in my (upgrade) experience, if a new piece of equipment did not sound better than the one it replaced right out of the box, it never improved enough to justify the upgrade no matter how long it was played. Cables were exceptions. Warm up is also a completely different story.
Equipment break in question
To break in a piece of equipment such as a DAC, do you need to turn on your amp and actually play music through your speakers? Does it work to just play a disc silently without using the amp and speakers? What about just turning on a component such as a DAC and leaving it on without playing anything?