If you've not worked with tubes before you should not even attempt it. The voltages are very dangerous, and one wrong connection will fry the tube. Or you. Probably you first, then the tube. I mean it, these things are hot and hard to get right for the DIY'er as it is. It cannot be made by joining wires. Biasing up a tube circuit is not for the faint of heart, it's not plug and play. I would suggest trying a few simple discrete circuits to get a feel for building point-to-point, and then going for the tubes.
Though you may think that both me and aks were going for your jugular, the fact is that you shouldn't be touching tubes unless you're very, very sure of what you're doing. There are very few DIY'ers around, and it would not be good to have that number reduced by one, due to them trying something they should not have. Not good for the hobby.
As to the circuits, both the posted ones are unsuitable, and the second one is incomplete. If you're looking to 'soften' the sound, try the Pass B1, it's a well-documented SS unity gain buffer projected with tons of support on DIYA. If you still want to push ahead with tubes, try this for size:
Practically, getting linear response from a single active device in one stage is extremely difficult, though a cathode follower built around a ECC83 or 12AX7 (shudder!) should work. This should be pretty easy to locate on Google with just the keywords.
Viren's Lyrita is extremely competitively priced. I don't really see the need to venture into the wild unknown when a known product is available at a price like that. But anyway, you guys know best.
Good Luck. I am not responsible for any injury caused as a result of this post. Have a nice day.