Cable burn in

Only mechanical things need a bit of run-in - speakers and phono cartridges. The rest no! Certainly not wire! Wire is the biggest rip-off going - and makes the most profit. No wonder it is so highly touted by the various cable companies. They want the unwary consumer to believe that there is an ever-upward (and increasingly expensive) path towards cable nirvana! Nonsense! In a blind listening test a cheap interconnect/speaker wire/ power cord cannot be told apart. Those that claim to hear differences are affected by confirmation and sighted biases. So don't waste your money on boutique cables. Stick to Monoprice and you will be fine!

It would be a wonderful world if changing a piece of wire produced an improvement. Alas, that is not Reality!

Harshness isn’t in cables. Good cables can reveal harshness but don’t go back to bad calbles to mask it. Fix the source. You didn’t mention your DAC.

Also your tolerance for harshness can change. I fought harshness for a while with an amp. Sometimes it would disappear and life would be great. But it would come back.

Internet radio may be low res and thus you get rid of harshness.

So I’ll say harshness is a sign of progress toward a resolving system.

One thing you can investigaate is can you turn down the output voltage on your dac. Some good dacs have this feature.

Jerry

Every new cable I ever bought needed time to break in.
Usually between 100-200hrs is enough to get an idea of what it will sound like and most will settle at around 200hr mark.
Used cables that were out of the system for few days take between few to 24 hrs to settle.
That’s been my experience.

BlueJeans are very decent cables but they’re obviously not end game.

In addition to upgrading your interconnects, look into improving the power cord for the Cary. 

My DAC was mentioned. The Cary Audio DMS-650. It does have an output volume feature, I can play with that. Doing a direct A/B swap, the difference is not at all small. Other people have concurred. In my mind, and maybe that is the key, it makes perfect sense that various material choices, shielding, insulation and other design elements could certainly make a difference. Why burn in does not apply also does not make sense to me. Metallic elements are in play, the same as amps and speakers. Louis Armstrong singing Ssss's went from unbearable to not an issue. Granted there are many questionable things going on in my mind, but I doubt that such a stark difference in tonality is one of them. I would imagine that it is possible that high quality-ow dollar vs high quality- high dollar would be negligible. But the notion that there is no difference at all, especially since I initially went in with the "I'm NOT spending big on cables"  mindset is a tough pill to swallow. I am talking about spending hundreds, not thousands. I carefully chose my components under the bang for buck mantra. In summary, I guess that I'll just ask what the believers think about burn in. No need for the "you are a looney tune" crowd to keep chiming in. There is enough of that going on in the world regarding many other contentious topics.Thanks.