Vinyl-Tech

NEW! A section devoted to the technology of vintage vinyl record manufacture, starting with a key article which for me first gave the lowdown on acetates, mothers, stampers, stamper-wear, and pressing volumes.

Secrets from the groove Pt 2
Hi Fi News, July 2010 , writer Barry Fox (added to LJC April 11, 2015, scans to read at full screen)

Key points:

  • Number of mothers and stampers from one acetate master
  • Stampers progressively wear out

“A stamper starts wearing out from the very first LP pressed. As the ridge tip gets blunter, the pressed groove shallows …”

  • Maximum records that can be pressed from one stamper

 “3,000 to 6,000  according to industry estimates”

 

  • Usually the first pressings would be best
  • Importance of drying labels before manufacture
  • Importance of cooling after pressing, and time to bagging
  • Vinyl purity and use of recycled vinyl – they knew
  • Vinyl sounds much better than CD (OK I made that up, the article doesn’t say that. It’s hifi mag. Every reader already knows that)

HiFiNews July2010 p1HiFiNews July2010 p2HiFiNews July2010 p3

HiFiNews July2010 p4

 

5 thoughts on “Vinyl-Tech”

  1. “A stamper starts wearing out from the very first LP pressed. As the ridge tip gets blunter, the pressed groove shallows …”

    Thanks for putting this in italics, LJC. We really didn’t know that.
    So, unfortunately, even the first LP pressed from a stamper is not really perfect, it’s faulty in a way, right?

    But still there is one thing that is less faulty even than the first LP pressed. It’s called a master tape. (Some people, admittedly, don’t like its sound because it’s so lifeless and “sterile”.)

    In the far future, people will find ways to preserve the sound of master tapes and make copies without having to use stampers. And those copies will all be perfect images of the master tape, to a degree that no one, NO ONE will be able to tell the difference.

    Hold it, folks, you’re trying to tell me that this kind of technology has been around for over thirty years? You’re kidding.

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    • The article is what in courtroom dramas used to be called People’s Exhibit #.

      Not to say I do or don’t agree with it or indeed some of it, but it’s the author’s notes, made on a tour of pressing facilities in the ’70s. Something difficult to reproduce or verify today, as these plants are mostly gone and the people who worked in them mostly pushing up daisies.

      This was the first article I read that put numbers on things, an engineering trait I rather like, rather than the “theory” of matters. Even if the numbers are wrong, they are at least a start point from which to find better numbers.

      When Scotty says the Dilithium Crystals are exhausted, no more warp power until they are replaced by new ones, you had better believe it. It’s the engineers job to know.

      Scotty

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