Cable burn in

Only mechanical things need a bit of run-in - speakers and phono cartridges.

Electronic gear also needs to burn in before it stabilizes. Amps, Preamps, tubes, CD players, anything that builds heat. 

Some tracks sounded almost muddy. The sparkle was diminished in an obvious way. I am guessing that once burn is complete the sound will settle happily in the middle somewhere. Is that a reasonable assumption?

That has not been my experience with cable burn-in.  Once they go in a certain direction they do not tend to go back from where they came.  Just my experience FWIW, but you seem to have good ears so just trust them because, in the end, that’s all that matters.  DH Labs would be a good cable to try if the Blue Jeans don’t settle in to your tastes as they tend to sound neutral with good detail and without breaking the bank.  Best of luck. 

@soix 

+1

There is no definitive answer to what would be best in your system… it is dependent on your whole system, venue, and your values. I can attest to the fact that cables, interconnects and power cords can make a very substantial difference. 
 

I also cannot be sure what different brands will sound like in your system, but I will say Blue Jeans are at the very budget end, I tried a couple pair just for fun and they compared well with what comes free with low fi electronics and I have used DHLabs as my default interconnect to start with. DHLabs has always performed well for the price and is appropriate in price for your system. 
 

A very general rule of thumb is about 10% or so on interconnects. Widely different % work for different people. But just for your interest. 
 

A well constructed power cord designed for both shielding and high current is likely to improve the sound of your DSM… I would look carefully at AudioQuest. 

  I’ve experienced cable burn/ break in time varies depending on the particular cable. The Morrow IC’s I have took 400 hrs, which is significantly longer than most. And as much as I respect others opinions , I’ve had significant changes in SQ by swapping cables, most effective being IC’s. Saying it doesn’t make a difference is like saying “ tube rolling doesn’t change anything “. I have changed cables and power conditioning methods and had zero improvement, but I’ve also had improvement too. So for me , I try it and see what happens, and I encourage others to experiment. And I also understand the concept of diminishing returns. Eeyore won’t even try , an audiophile will take the risk, Now go raid the honey jar . Enjoy the journey, Mike B. 

Hey chiadrum I have a Cary DMS-600 I bought used as a trade-in from Cary and am enjoying it immensely.  I asked Cary if it was a truly balanced circuit (conforms to AES-48 standard) via XLR's and they said yes (?).  I run the Cary direct into balanced Atma-Sphere class D monos via Mogami Neglex Studio Gold XLR's I bought from Sweetwater Music for about $120 pair.  At some point I may try something better just to compare but doubt they can be topped much in a truly balanced circuit from what I've researched.  Cheers and enjoy!