> from an engineering standpoint Yes. The class-D amp I got for $20 runs circles around anything that can be done in tube technology, just in terms of fidelit

> from an engineering standpoint Yes. The class-D amp I got for $20 runs circles around anything that can be done in tube technology, just in terms of fidelity. But a musical instrument is not viewed purely from an engineering standpoint. Using your piano example, the material you build the piano frame out of affects its resonance. Early pianos, not steel-framed, sound different. Even if we can capture this with a synth some day, the art of piano-making, the tools, physically making the musical instrument, will be an art and science worth preserving and practicing. Same is true for the electric guitar. And so part of that art and science, will involve tube amplifiers. Just as the study and making of pianos, involves the study and making of making wood vs. bronze vs. iron vs. steel frames. Even if most of us piano players just play on an electronic keyboard most of the time.