tube mounting inside sockets question

Hi, I just changed power tubes on my Herbert, is it normal some socket need more attention when fitting in a tube inside? One of them had like a instability feeling like the plate wasn't 100% flat , so I had to double check the tube was correctly inserted-pushed down and totally flat to the socket in contact. The other five were perfect.
(Of course I put them in the correct position, aligned and inserted in the circular fashion).
Clamps are there for that reason and to keep tubes firm and stable I suppose, anyway...
Thanx

If you swapped out your power tubes with new JJs it's not uncommon for the base socket pins to be slightly less in diameter than for instance a Ruby EL34. In this case identify which power tube socket seems a little loose, then simply remove Herbert from it's chassis. Then with a very small jeweler’s flat head or a small awl gently tighten (close) the individual "internal" socket clamps.

These are of course not the external power tube clamps grasping the power tube on your Herbert (which in my opinion do nothing).

Also, you always want to line up the power tube "guide pin" at the base of the power tube to the socket. There's no inserting of the power tube in a circular fashion, it's planted to the power tube socket base straight down.

Another side note: I would also recommend that any time you are replacing power tubes in any guitar tube amplifier that you apply a spritz of DeoxIT to the power tube pins and work the power tube in and out of the base socket 2 to 3 times. This will help to eliminate any unwanted static noise. It's also not a bad idea to do this to your preamp tubes too.

yes the guide pin is aligned of course, i don't want to light my Herbert and house on fire i get what you mean, i don't know if is because of the internal pins on the socket in my case, btw it also may be. This is the 1st power tube changes so pins shouldn't be that loose...
i didn't try another tube there to see if it was a kind of different spacing issue from the previous one, or the internal clamps on the socket. i'll check that next tube change thanx