Mark IV noob tube question

[weemies]

I just received my MkIV. There is no preamp tube in the V1 shielded socket (on the right in the pic). I'm guessing that is a problem... The other 4 preamp tubes are there, and power tubes as well (which are missing from this pic, because I removed them).

The seller did include two extra power tubes and two 12ax7 preamp tubes, but I can't fit a preamp tube into the socket. Do I need to put the tube in there?

 

[Living_justice]

hell yes you need a preamp in there, why cant you put one in there?, just remove the shield cover, push up and turn and pull down should move.

 

[weemies]

Ok, nevermind, I removed the head from the chassis, and the tube is already in there, it's just not visible from the back of the head.