[Arran]

Mike;
  I've been looking into the Chinese radio industry, at least from the tube era, and it seems that they either used North American style tube types or Soviet tube types. What I don't remember is whether they used Cyrillic letters on some of the Soviet types or all. The tube shown looks like it has a number 75 on it as well, maybe a manufacturing date like 1975, followed by XI, 11th month maybe? An interesting arrangement of the two triodes, cathode follower I think. Is that a 6SN7 or a 6SL7?
Regards
Arran