How long did your Shanling ET3 transport break-in take?
I don't feel qualified to respond to this. I don't pay much attention to break in times. I just listen to music. I can't say with any authority that it sounds better now than the day I got it. And, when I got it I had a Chord Hugo TT2 and during the first month I switched to the Holo Audio Spring 3 KTE. So, I'm not sure where the sound changed and why. When I tried USB output I did not like it. I also tried Toslink and that was better. But when I went to I2S with a $5 hdmi cable I felt it sounded best.