South43,
Some of the tube MFG you mentioned are the reason that you don't hear of them. Ei is where the old Telefunken equipment went when they sold the equipment, and most of the tubes used in current production gear from the mid 1980s through 1993~5 (when the war started) came from the Ei factory. Mazda Tubes are very old and most of the "modern" tubes, like the 12AX7, 6DJ8, etc. were never made by Mazda.
Hope this helps your question.
Some of the tube MFG you mentioned are the reason that you don't hear of them. Ei is where the old Telefunken equipment went when they sold the equipment, and most of the tubes used in current production gear from the mid 1980s through 1993~5 (when the war started) came from the Ei factory. Mazda Tubes are very old and most of the "modern" tubes, like the 12AX7, 6DJ8, etc. were never made by Mazda.
Hope this helps your question.