Interconnect Break In?

I also think it's your ears and brain that are "breaking in " when you make a change

It’s never without you adjusting to new sound but it’s not the only component involved here. Allowing the cable to settle is also important  

Try making a change, listen for an hour then let it all play and come back the next day. Evaluate. Then leave it playing for a week before you listen again. If you’re capable of hearing the difference between the cables you will most likely hear the difference between the initial listen and when the cable had settled.

Even a used cable that’s been out of the system for some time needs a few hours of play time to settle. 
 

Rule is though, if you absolutely hate the sound with the new cable right out of the gate, no amount of break in will fix that. 

My experience is that it takes a minimum of three days for any cable change to settle in to the system and show it’s true character. Whether it is my brain or the cable I do not know, but it seems pretty consistent. 

Was looking at cabels the other day a major manufacture stated it takes 100 hours.maybe they got tired of returns and the cabel did change or the brain adapted.thats why some manufactures cryo thier cabels putting the atoms back in thier lattus structure so less change. Atoms do move around unless - 273 degree kelvin.then it stops and so do i.ebjoy the music and the hunt

I agree the preamp does not need to be on.