Paul,
Good review thanks!
I will look up my Tungsram tubes and try out.......
I think your Tungsram tubes is good because well-matched...
The last time i found Tungsram and Telefunken in my AC50
I replaced Tungsram --> old (not very old) Ruby tubes

hmmm Each tubes sound good.
Maybe Tungsram better for Marshall

I never put Tungsram in my Marshall......... i will try out
Sub