Right now its not too much of an issue, but even in high end remains the simple question of what if a solid state amp comes along and sounds better than the tube competition?
Thank you. This helps me see there are two distinct rationales for developing new types of amplifier -- one is the possible tube shortages and the other is the potential for amplifiers that are more energy efficient, easier to maintain, and perhaps more amenable to a wider set of speakers while sounding as good. I suppose the "as good" part will have to include "as good and tube-like" for those of us that like tubes, but I suppose there can be a lot of ways to accomplish that. My Pass XA-25 already proves it's possible.

