Lanny,
I would say about a 3-4 weeks to break in using all formats whith usually a cd/sa-cd running 24/7 when not actually listening to the player, or using it to watch a flick.
The soundstage grows wider and deeper whith 150-200 hours and the overall sonics remain much like stock whith everything improving somewhat.
The thing whith the sp 1000 is once you start listening to music, you don't want to stop, so I had very little time for it to break in whithout actual use.
Normally, I will listen to a digital source and then let it run 24/7 for 4 days, listen again ect,but the sp 1000 got my toes tapping like they had a mind of there own, right from the get go.
If I had to guess, I would say there is a 10% improvement in sonics across the board after 3-4 weeks.
This is the first digital source I have owned that sounded musical right out of the box besides my Modwright signature 9000 es which was already broken in when I bought it used.
In other words, I did not pay much attention to break in like I normally would as I was enjoying the music too much.
Greg