Hi Need advice please. I have a pair of AWV Radiotron 6SN7GT tubes Made in Australia one of which has a small crack in the base. I have come accross another for sale which is also a AWV Radiotron 6SN7GT. It has identically the same getters micas and plates etc but has different markings. Both tubes have a 1/4 inscribed on the black bases but where they differ is that one is slightly rounder on the top of the glass and one has inscribed on the base B7 the other V8 inscribed. Will they be sonically the same ? Any idea what years they would have been manufactured ? Thanks Barry
Don't worry too much about the crack in the base as long as the tube is functioning properly. If the tube mechanism is sealed in its vacuum inside the glass, it won't affect anything, and should perform fine. Just handle it more carefully.