Two other items I found needed break-in: my Sony 940C 75" TV and my KitchenAid 29 cuft. frig. The TV had a overly sharp looking picture. After 30 days, the image smoothed out. Then I calibrated it. The frig was worse as it made many noises, shooshing, creaking, whirring, etc. noises. After 6 months, a long time, it became nearly silent (4 years later, same). I attributed that to compressors, motors, etc. breaking in.
I am a cable beta tester for a manufacturer. I can never tell if a cable is worthy until after it breaks in for at least 24 hours. Most of the cables sound good but have affectations which limit my enjoyment using them at the beginning. After 24 hour burn-in at 1.5 to 2 volts for ICs, a frig use for IEC / A/C cables and unknown voltage/current for speaker cables just through use, I get a definitive result, better, about the same or worse than the existing design.
I am a cable beta tester for a manufacturer. I can never tell if a cable is worthy until after it breaks in for at least 24 hours. Most of the cables sound good but have affectations which limit my enjoyment using them at the beginning. After 24 hour burn-in at 1.5 to 2 volts for ICs, a frig use for IEC / A/C cables and unknown voltage/current for speaker cables just through use, I get a definitive result, better, about the same or worse than the existing design.