I own a cherry '67 super reverb. I am the third owner. The second owner has had the amp since '72. It is loaded with mullards and ge's. I believe they as old as the amp, but possibly a bit newer, not much. Here is my problem. I own two super reverbs. The '67 is much quieter than my other('66). The 66 has newer tubes, it is much louder, but not as articulate and sweet sounding. So, what do I need to replace, in order to get my amp singing at a higher wattage? I don't want to dump tubes that are vintage and great, unless I need to. Power tubes? Preamp tubes? Rectifier? All of them? Help, I need it. Thanks in advance.