Does anybody know the best tubes to get for an Ampeg SVT 2 Pro? I'm in search of new power tubes for my amp and I'm not sure what the best option is for me. I've never owned a tube amp until the last few months and it is making some really weird noises which lead me to believe my power tubes (maybe more) are spent. If anybody has any insight on this I'd really appreciate it. Does Ampeg recommend Sovtek or Electro Harmonix or what?