Shuguang black treasure 2a3-z...

I have been running a set of sovtek 2a3's on my wright sound 3.5 monos. The sound was instanly better on my klipschorns than the KT88 on another amp I was running. Only issue I had was the lean bass. So, I dove into the deep end of cost and these beauties just came in today. They have been running for about half an hour now. In a word... WOW!!! My bass is astounding. ALmost as good as the KT88. Was worth every penny and just wanted to share as there isn't much out there on these magnificent tubes.
I agree with you , I`m using the 300b version of the treasure series and it`s a wonderful sounding tube. The musical flow and realism is quite special. There`s a current review of this tube on the 6 moons site. I`ve had mine for 9 months and could`nt be happier.
I've tried Sovtek and EH 2A3 tubes in the past, and both were incredibly disappointing, sounding just as you had described.

I would expect the Black Treasure tubes to improve a whole lot from what you heard after 30 minutes. Usually, a tube really comes into its own somewhere in the 50 - 100 hour range, but other threads on these tubes seem to mention 300 hours.

For those who are not able to swing for such an expensive tube, I've found the Shuguang 2A3B to offer much improved sound at a lower cost over the Russian variants. The Shuguang 2A3C, though a bit more than the 2A3B also is a great choice, and justifies its increased price.