I've never had any buzzing or noise coming from the spring tube retainers. The other option is to try and tighten your pin slots in the socket themselves. You can actually buy a tool for doing it, but I use a jewellers screwdriver and gently slide it down beside the pin slot and push it tighter together. It works good and tightens up the hold on the tube itself.
Wild Bill is right, don't bend the pin on an octal style power tube (6l6, el34 etc) as you will probably end up with a broken pin and or tube base.
