Yes, they are close together and can be a tight fit with more "stout" tubes. There are solutions to this, however....
The Sophia Blue 6SN7's will fit, but they touch. Also, IMO, they're very "meh" tubes - there are other much better options out there.
@Deyan does make what I called "offset" adapters for the Woo WA5-LE. I had him make a pair for me specifically for testing some fat-boy tubes that would otherwise not fit:
I can highly recommend his work when it comes to adapters. They're not as pretty as Woo's, but they serve a different purpose.