The stock tubes in the MS-22B are not bad at all. They are latest generation Shuguang, and they sound quite good.
I have tried a lot of tubes in it. The TAD 7025S is a great tube, but i don`t like it in Yaqin, for some reason. My preferred is the ordinary TAD 7025, which are selected JJ`s. A clean clear tube, with just a hint of warmth to it.
OT: That said, i am not too impressed with the MS-22B. It sounds nice, and is worth the money, but not much more (IMO off course).
Amp: Pass Labs INT30a. Digital: Yamaha CD-S1000, Streaming: Chromecast Audio, M2Tech Young. Analog: Rega RP3/Elys 2. Speakers: Dynaudio Excite X32 and JBL Studio 290. Cables: VDH First Ultimate, VDH First Metalscreen and Xindak FS-0.5.