Nice! I also have one of these amps and it started me into tube rolling, Your fav is probably very similar to what my favorites are as well... Let's compare.
shuguang treasure kt88-z black bottle x 4
Shuguang Solid Smooth plate gekt88
rca vt231 grey bottles x 2 in v1 and v4
RCA 6sn7gt black plate bottom getter same spots
brimar 6sn7gty/cv1988 black bottle brown base x 2 in v2 and v3
Tung-sol 6sn7gt (Mouse Ears, more on the smooth, well rounded imaging and ambiance with excellent detail and focused midrange...)
telefunken 12ax7 smooth plates x 2
Sylvania 5751 grey-plates 80's... beat the telefunken and the sylvania 5751 black plates, rca's mullards etc, I highly recomend trying these ones out, they may give you the bass you're looking for and are still a very tight resposive tube like the telefunken...
Anyway havn't rolled in this amp since I came up with this combo as well years ago...