Burn-in time for a Shuguang 845B tube?

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.

Sorry to hear that! In my case the originals tubes are Sino 845 and the replacements are Shuguang 845B (I guess Shuguang makes them for Sino). So far the difference is notable in all regards: soundstage, bass, definition, etc. I hope that as time goes by the tubes will improve a little more.