Burn-in time for a Shuguang 845B tube?


About how many hours does it take to burn-in a Shuguang 845B tube? Can I expect a big change in sound as time goes by? Right now I have logged about 30 hours on a pair of 845s and the sound is still rough in the edges but I like more thant the regulars 845 (not B o C). The tubes are installed on a Bel canto SETi40. Thanks in advance for your comments.
tiofelon
Well I just past the 50 hr mark and the sound started to open up, the rought edges are (almost) gone, but I think the biggest improvement is in the soundstage area! The music is wide, tall and deep as it suppose to be! I guess a few more hours should bring more detail and smooth the music a little bit. Thank you all for your comments!
I can tell you that my Shuguang 845T's took about 75 hours before they started to open up. By 100 hours they had stopped improving.

I remember when I first dropped them in to the amp. They sounded horrible, and I thought that I had made a serious mistake. They were closed in, sounded muffled, and had poor dynamics and no sparkle. Now they are the opposite - open sounding, dynamic, great sense of scale, and pleasant to listen to.

Keep the faith :) And good luck!
Amfibius,

Besides the Shuguang 845 T tubes do you any experience with some others 845 tubes burn in time?
Yeah, the original 845's that came with my amp. But that's not really relevant because the whole amp was burning in at the time.
My experience has been that the graphite plate 845 take less time to burn in than metal plate 845.