[NB-SK]

I'm not expert, but I would space out the connectors a bit by slightly bending them. That should solve the problem.

 

[NB-SK]

The other guys are right: while bending the pins on smaller tubes like the 12ax7 is doable, it could damage a power tube.

Go for the spring retainers for a more permanent fix. The ones I've seen are mounted by using the same screws that hold the sockets.

If the springs are too long and/or the cap is too large on the power tube retainers, just bend the tongues on the caps so that it fits snuggly against the tubes to reduce the rattle. Don't know if there is a better solution, but this is what I did when I went from a large power tube to a smaller one on my 20watt amp.

 

[NB-SK]

This is how it is done and is usual but BE SURE the caps are discharged. Use a meter.
The tubes pins should be as straight and perpendicular as possible and there is a special socket for repairing ones whose spacing is out of whack.
You might keep a new regular socket around just for this purpose since those special ones are hard to find.
The reason being that it can make them hard to put in, it causes the spacing to be off, which is why the socket became loose in the first place.
You can also do it by eye (9 pin mini's only)but dont bend the tubes pins too much they break very easily.
If the octal tubes pins are bent. Dont chance it, leave them, they are hollow.


PS If you can hear the retainersprings rattling in there your not playing the amp correctly...TURN IT UP!... )

Of course, but by rattle, I meant when you touch the tubes. It would think it's safer to have the retainer properly fitted than not.

 

[NB-SK]

Change the tube sockets!You are wasting your time trying to re-tension the pins and fender's are notorious for poor contact in this area.Do not use ceramic tube sockets,as they are poor quality unless you get the new style fender ones used in some new model production amps.They have a 'memory' on the pins and will last longer than the originals.Tube retainers are a band-aid at best.Ask any tech who has tracked down crackles and low output power on an old fender amp.
I use Belton tube sockets with tremendous success.If you cheap out and get lazy,you will reap the penalty.Do the job once.

www.claramps.com

Good advice.
It's easier said than done, but it should certainly be considered. Get it done by an amp tech unless you know your way around an electrical circuit.