Digital quality has already surpassed analog at one quarter of the cost.
One does not need to know the technology to know this is not true. The reason is simple: the period of least vinyl production was 1992-1993, which to be clear was about 27 years ago! Vinyl has been on the increase in sales ever since and the only thing limiting it that long ago was the record labels themselves.
So you have to ask- why is this format still around?? Usually when the prior art is surpassed by the new technology, the prior art is relegated to dust bins and museums (think about side-valve engines and you get my point). I know a lot of people that did get rid of their analog library and have since regretted it. The only real answer here is that people still want vinyl even though digital is ubiquitous and accessible. About all you can say about that is there is something about the LP that people like enough to keep it around and when you ask people why (and I'm talking about kids and non-audiophiles) they often point to the sound- metal heads like the superior way that the LP does the cymbals when played at ear-splitting volumes; the CD is too 'crisp' and so on.
Now I have some ideas about why vinyl might sound better- our mastering lathe has an older Westerex cutter head, and its got no problem going out to 40KHz, which is a bit of a trick for digital. In additional almost any phono section has bandwidth that high, and so do most cartridges. When we test our system, we cut a 30KHz tone and play it back on an older Technics SL1200 I got on Craigslist, equipped with a Grado Gold, and played through an older Japanese MM phono section- and there is our 30KHz tone (we do this so that we can be sure our cut can be played by an ordinary turntable). In addition, once the cutter is set up right, it can cut grooves so quiet that it does not matter what electronics you have- they will be the noise floor. The surface noise comes in during the pressing process.
I've also found that most people that prefer digital are turned off by the ticks and pops of vinyl. But in my design work of phono preamps of the last 40 years, I've found that phono preamps can generate ticks and pops that sound for all the world as if they are on the LP surface. These can be caused if the phono section has poor high frequency overload margins and stability issues related to the simple fact that cartridges are inductors. If you are able to recognize these facts as a designer, you can make a phono preamp that exhibits less ticks and pops. I'm very used to hearing entire LP sides with no ticks or pops whatsoever. Now there are a number of phono sections in high end that have proper stability in this regard, but what I've found is that if you grew up using inexpensive phono preamps made in Japan for MM cartridges, the probability is very high that you think that ticks and pops are endemic with LPs.
