Inner or outer tubes? Einstein 100w

[otot]

Hi! I have a simple question, I have some troubles with my 100w Einstein. One or two of my powertubes does not work, El 34. I have bought SED 6550 but what means inner or outer tubes, there ar four in row. Let`s call them 1 2 3 and 4. Is 1 and 4 the outer, 2 and 3 the inner powertubes? Pleas help me

 

[Peter Diezel]

Yup ...... 1 and 4 outer, 2 and 3 inner tubes.