@no_regrets many "experts" (e.g. professional audiophile reviewers; electronic engineers; neuroscientists; etc.) would argue that break-in or burn-in time for various audiophile sound system components is a myth. Of course, there are some who argue that some amount of burn-in time for some components actually does benefit their performance or sound fidelity. Still others argue that what is happening when someone thinks they hear a benefit of burn-in time for some components is that their ears or, more precisely, the auditory cortex of the brain becoming accustomed to the new sound signature, vis-a-vis the acoustical characteristics of the home or sound room.
In my experience, over the last 5 or 6 decades, I've found that electronic components like amps, DACs and CD players require virtually no or negligible periods of burn-in or break-in time. Although I've never owned or lived with one, I have no trouble believing that very large or very powerful amps need or benefit from warm-up time. However, I have difficulty believing their sound fidelity would improve or benefit from a certain amount of burn-in or break-in time. The non-exotic turntables and cartridges I've owned, similarly, did not seem to need any burn-in time to speak of. However, the TT I have now definitely did benefit from a couple hours of spin time in order for the motor spindle and bearings to become properly lubricated. As for the speakers I've owned and enjoyed over these many years, I think I've noticed very small improvements in some of them (more high-end or expensive ones) after a certain amount of burn-in time. However, a somewhat famous professional audiophile component reviewer who shall remain nameless told me this was all in my head (i.e. auditory cortex). The salesperson who sold me the pair I have now advised they would need approximately 90 hours of burn-in time to reach their full potential. A professional reviewer told me they would need closer to 100 hours and yet another wrote in his review of them that they fully blossomed after approximately 110 hours. Since I had a 30 day return policy from the shop that I purchased them from, I decided to listen very critically and keep a log after I brought them home. Auditory Cortex notwithstanding, it certainly did seem, to me, that there were small improvements over time, mostly in bass response, to a lesser degree in high frequencies and negligibly so in midrange after somewhere around 60 hours.
So, as in all things, let conscious be your guide! However, that being said, I think running your CD player & DAC 24/7 is accomplishing nothing other than wearing out those components.
