I have an original 100 watt Lonestar, which I love love love. I never use the 5U4 tube rectifier because I always have the amp in 100w mode, which automatically switches in the solid state rectifiers. In the past month the amp suddenly died at a gig. Apparently my power tubes went to heaven and blew the amp's fuse. I took the amp to the shop and had it checked out; all it needed was a new fuse and a new fleet of power tubes. I didn't replace the rectifier tube because I never have the amp in tube rectifier mode. Two weeks later the fuse blew again. I took it back to the shop and my amp tech informed my it was possibly the rectifier tube, even though it's technically not in the circuit. We bench tested the amp and sure enough, even when the amp is in solid-state rectifier mode, the tube rectifier is still getting several hundred volts. I have a replacement Boogie 5U4 but my tech told me just to use the amp with that socket empty. It seems weird to me to have an empty socket so I'll probably wind up putting a plug-in solid-state rectifier in its place just so it's safe if someone accidentally switches it over to the "tube rectifier" position on the back. Is this an unusual behavior for a modern tube amp? I know the trend in modern amp design is to omit tube rectifiers in favor of more stable / reliable solid state rectifiers. I'm interested in hearing if others have had similar experiences.