- Aug 8, 2010
The 6J5G (ST Coke bottle shape) tubes appeared first in 1936.I have the Tung-Sol 6j5g (vt-94 a - (coca bottle and black base) and the Tung-Sol 6j5gt (vt-94-D - metal base).
To my ears, the Tung-Sol vt94-d sounds considerably better.
I believe they are older.
The 6J5GT (straight glass) appeared first in 1938.