Saki,
I used the Shuguang Black Treasure 6CA7 in my Primaluna Dialogue One. It sounds to me to combine the best attributes of my NOS Reflector 6n3ce (6L6) and my NOS RFT Siemens EL34. Better detail and air, yet full, a drop of warmth, increase of quality bass. Generally all around better in my system. The Simens are also good performers. You might also like the Bugle Boy 12au7s in combo with Sylvania 5751 3 Mica Black Plates in the Primaluna. I know I like them a lot.
I used the Shuguang Black Treasure 6CA7 in my Primaluna Dialogue One. It sounds to me to combine the best attributes of my NOS Reflector 6n3ce (6L6) and my NOS RFT Siemens EL34. Better detail and air, yet full, a drop of warmth, increase of quality bass. Generally all around better in my system. The Simens are also good performers. You might also like the Bugle Boy 12au7s in combo with Sylvania 5751 3 Mica Black Plates in the Primaluna. I know I like them a lot.