Whether there’s any physical burn in is debated (IMO, any such effect will be minimal, if any). No one has good data on that from proper testing.
Your ears/brain may adjust to the sound over the course of dozens of hours, making it seem better over time. In that regard, other psychological factors can also substantially influence your perception of the sound. Give it some time.
The DAC/amp should make minimal difference, unless you’re using a unit which colors the sound or an underpowered amp.
The recording quality makes a huge difference. Some recordings will sound like crap on any system, others will make the Clear shine.