Oh, it absolutely can. The target market for tubes isn't people who do double blind tests, though.

They want tubes and the tube sound, not just the sound. I can understand, it's a matter if authenticity rather than practicality. Just like a kit car replica versus an original car. The original will always be more authentic, and there will be some who care more than others.

Indistinguishable is a mighty strong word. We haven't completely mastered digital audio and to think we have is foolish (I do DSP for digital audio for a living, I'm Chris from Airwindows)

Also, a tube has absolutely no latency.

> a tube has absolutely no latency

I think that's the primary key here. We can decently emulate a tube amp in software even (and that can improve indefinitely as our knowledge improves), but we'll never create drop-in circuit element emulators either in silicon or software without adding latency.

As far as guitar tube amps go - check out a Kemper Profiler or Fractal Audio system, it's pretty much there. That said, I'd take the pure simplicity of a nice tube amp any day.