Most likely your amp has bias adjustments for each output tube. Each output tube needs to be in the same socket that it was in when the tech performed the bias adjustment or you have to start all over with bias adjustments.
If the seller took the time to mark each tube for the proper socket before he shipped it, you might be able to move them around to their proper location and be up and running again. If not, and if the tubes were simply shipped independent and without any indication of which socket they go in then the seller didn't take his responsibility of selling serious.
Tubes can vary in how bright they are and still be biased properly. A tube with a filament that extends higher above the plate structure than another will glow brighter. However, if the plates are the least bit orange or red then you have a problem.
If the seller took the time to mark each tube for the proper socket before he shipped it, you might be able to move them around to their proper location and be up and running again. If not, and if the tubes were simply shipped independent and without any indication of which socket they go in then the seller didn't take his responsibility of selling serious.
Tubes can vary in how bright they are and still be biased properly. A tube with a filament that extends higher above the plate structure than another will glow brighter. However, if the plates are the least bit orange or red then you have a problem.