Actually tubes produce much more linear power and amplification than most solid state amplifiers are capable of.
Hi there
When it comes to AUDIO we have to remember that our ears hear ANALOG so any sort of high quality ANALOG device will in theory blow away digital components. A digital sound source needs first a DAC (Digital Analog converter) to convert the Analog sound source to digital and then another DAC to convert the digital signal back into analog for the ear to hear it.
DAC's work using a mathematical principle known as Fourier analysis which means you treat everything as parts of SINE WAVES. The DAC takes a small sample from say the analog signal and tries to break it up into a digital set of 1's and 0's. To convert back again it's done in reverse.
The quality of the DAC's plays an important part in any decent digital sound system (as obviously the speakers etc). So even before comparing Analog vs digital sound amplifiers you have potential losses and distortion that can be caused by the DAC's. Also an analog system has an infinite set of gradations -- for example if there are any digital photographers out there you know how hard it is to get a really stunning Black and White print -- there are an infinite number of gradations in the grey scale which can't be reproduced on a purely digital format - usually the digital format takes say 16 / 32 bits at the most. For colour this works as the eye isn't that sensitive - but it fails miserably on black and white !!!.
The Analog amplifiers aren't old wives tales - they can easily outperform any digital component. Vinyl is different though in the sense that there's FRICTION involved and it's very hard to re-produce accurately a mechanical representation of sound without introducing noise and other errors - although modern equipment is very good indeed.
Most computer sound systems are absolutely APPALLING - but probably fine for things like game playing and watching the odd DVD with loads of bangs and shootings etc.
But listen to some high quality LOSSLESS classical music for example on things like Mission reference studio speakers -- You'll never even want to LOOK at a pair of bud earphones again.
As far as CRT's are concerned - apart from energy and environmental concerns they were always subject to flickering - due to the way the scanning process worked. They were hideous as well once you started getting sized beyond about 14 inches. I'm not sorry in any way whatsoever that those things have GONE. RIP CRT is what I say and good riddance to them.
Cheers
jimbo