You are, in fact, dragging a rock through a groove made of plastic with
force equal to hundreds of psi. The rocks wear out. I'm pretty sure the
plastic does too.
This is a common strawman. There's no rock.
And this is kinda why I don't take vinyl fans
too seriously. It's common knowledge vinyl is worth about 50 plays
before it's lost noticable quality.
I would not call that common knowledge. I have LPs I liked so much that I played them every day for a year (Michael Oldfield's Songs of Distant Earth) and they still play fine. Still good too 25 years on... (that LP came out in 1993, the year of least vinyl production; A friend of mine and I imported all the original copies of this LP into the US 25 years ago)..
And then there's the obscene
expense in just competently playing the things, as you pointed out.
What's a halfway decent DAC cost? A few hundred bucks? A couple Grand
for a really nice one? For distortion and dynamics that absolutely
destroy vinyl.
The digital industry does not like to talk about aliasing, but it is a form of distortion and is in the recording- no matter how good your playback is, the digital playback tends to be brighter than real life since the ear converts that distortion (known in the analog world as *inharmonic distortion* and is a form of IMD) into tonality- in this case the brightness for which digital is known.
As for tubes...
They're material and labor
intensive to make. Nobody would have developed the technology if
something smaller, cheaper, and more efficient had come along
first.nobody is developing vinyl or tape anymore. And why? Because
digital is better. When superior things are born, inferior things die.
Like punch cards. Like floppy disks. Like horse and carriage. Like
typeset. Nobody will ever again develop a new kind of tube, except Korg
for whatever reason. Those are kinda cool. I might like to build a
pre-amp with some of those.
Henry T Moray developed the first germanium transistors in the 1920s which he later patented. IIRC one of the people that worked with him later developed the transistor at Bell Labs. Lilienfeld patented something very much like the FET in 1930. The problem with your statement above is this: Tubes were declared 'obsolete' in the 1960s. Its now 2018; tubes have been 'obsolete' now for longer than when they were the only game in town, thus debunking your claim above, since apparently they must not be 'inferior'. You don't have to know anything about engineering to understand this- its purely economic. If tubes were really inferior, they'd be gone, but the marketplace keeps them around. The market doesn't keep flathead engines around, doesn't keep punchcards and so on. Those are actually real examples of obsolete tech.
Vinyl is still being developed. Acoustic Sounds, a well-known high end audio LP producer in Salinas KS, has a pressing plant called QRP. QRP modified their pressing machines so they don't vibrate during the cooling process of the vinyl. The result is dead silent grooves. We've done some projects through them, but first you have to know one more thing:
If the cutter stylus is set right and at the right temperature, the groove that it cuts in the lacquer is so quiet that no matter what your playback electronics are, they represent the noise floor. IOW, in playing back a lathe cut, the lacquer is considerably lower noise than the best electronics.
Now the QRP pressings are so quiet that they often share this quality with lacquers. They've pushed the noise floor down by a good 10-20 db! I'm not sure how far, since the best we've been able to get our of our playback is -85 db and the QRP tests we've gotten back are quieter than that. So I'm just letting you know that your -70s figure that you've mentioned is a bit out of date.
