Thanks for all the inputs. I guess I'll be keeping the Tekton Lore speakers for a while as I'm so addicted to the sweet sound of the 300B tubes. In fact, I just ordered a pair of Shuguang Treasure 300B-Z tubes for the Yaqin.
for Franz456: I also had the Yaqin MS-20L with Gold Lion KT-88 tubes, wonderful mid but the bass wasn't as round and tight as the MS-300C so I would recommend the MC-300C over. 9.5W SET is just as strong as 50W push-pull so don't let the low-wattage fool you. But again, both was driving the Tekton Lore which are very sensitive (rated 95-98dB).
for Franz456: I also had the Yaqin MS-20L with Gold Lion KT-88 tubes, wonderful mid but the bass wasn't as round and tight as the MS-300C so I would recommend the MC-300C over. 9.5W SET is just as strong as 50W push-pull so don't let the low-wattage fool you. But again, both was driving the Tekton Lore which are very sensitive (rated 95-98dB).