The Friar, in the process of snickering at those folks who will pay four digits for very early record pressings, issues the following explanation of the record-making process, mechanical division:
Sound in vinyl records is encoded in the grooves, which are played when the turntable needle moves over them at the proper speed. The grooves are pressed or stamped into blank vinyl discs, and like all mechanical systems the stampers were subject to wearing out. Records pressed earlier in a stamping run were more likely to have grooves that are cleaner and more accurately reproduce the full range of the sound.
Ideally, the cutting speed and the playback speed should be identical, except when they’re not:
Mobile Fidelity Sound Labs stepped in to fill the audiophile niche market. Their Half Speed Masters were special pressings of the albums. They (smartly) realized that not all audiophiles were classical music buffs, and that the rock generation was beginning to come into its own, with big bucks to spend. Mobile Fidelity Sound Labs had made superior quality pressings of albums by using thick, virgin vinyl, and by locating low-generation copies of the master tapes and using those as a source for their albums. The term “half-speed” refers to slowing the cutting lathe to half-speed while cutting the album stamper, resulting in a more accurate and deeply etched groove that held low tones better.
Yep. Those platters were cut at 162/3 rpm, to be played back at 331/3. The short-lived CD-4 quadraphonic LPs were cut at even lower speeds, in an effort to get a 45-kHz signal onto the vinyl.
Still, all these “improvements” aren’t always obvious to the ear, either mine or the Friar’s:
Too many loud concerts have helped my ears have trouble distinguishing all of the Vitally! Important! Distinctions! that are supposed to be in all of this stuff. Those distinctions themselves may be a whole lot of suggestion bias: When you’re told a particular copy of a record sounds much much better than what you’ve been listening to and you agree to part with a few Ben Franklins in order to acquire it, the chances are pretty good that you’re going to believe it sounds better. Sure, a good LP sounds better than an MP3 file, but 1) almost everything does and 2) the idea that there is an experience of listening to some record that’s “worth” four figures is a product of a mindset that is so far removed from the everyday reality most people live in that it ought to draw its own “Occupy” protest.
Had I a bunch of thousand-dollar records, I probably wouldn’t play them at all, lest I reduce their value. Then again, I have always had the most middling of hi-fi systems, to the extent that those systems had any fi at all.