I have received a pair of Shugang Black Treasures and put them in the LS100. Below is the email I just sent to Dan Wright and Grant Fidelity...
I received the Shuguang CV181-Z (6SN7) Treasures and a NOS 5AR4 and burned them in for a few hours yesterday. Even though the LS100 and the tubes have only a few hours on them, I was quite unprepared for the sounds I heard during my first listening session. For the first time in my audio life my speakers literally disappeared, and the imaging filling my room was almost palpable...very 3-D indeed, to the point of being almost scary-real. I sat in wonderment; left wanting for nothing with the music being produced with such crystal clarity and startling precision from top to bottom. I can only anticipate what further improvements may happen as both the preamp and tubes continue to settle in together.
To be brief, my searching for the next best preamp is over, as is my searching for the next best tubes to put in that preamp. This combination has taken my humble audio system from good to "wow"!
Thank you Dan for designing such a wonderful preamp at such a fair price, and thanks also to Shuguang for producing a pair of tubes that have taken that preamp way over the top in audio quality. Job well done!