Never heard of a Siemens 7308 gold pin/Bugle Boy. Amperex makes Bugle Boys and has the BB logo. Also, there is no 7308, only 6922 and 6DJ8.
Siemens makes excellent tubes. Does yours have the BB logo of a whistling tube?
Good source...
http://www.audiotubes.com/6dj8.htm
Siemens makes excellent tubes. Does yours have the BB logo of a whistling tube?
Good source...
http://www.audiotubes.com/6dj8.htm