Vinyl record grooves under an electron microscope | Hacker News Reader

Vinyl record grooves under an electron microscope

synthgear.com

37 pointssoundsop8 comments

Many years ago I ran a record label, and as part of the process of manufacturing I took the source DAT tapes to a cutting studio, where an engineer cut the "lacquer", which is a one-off, soft wax version of what will later be pressed into hundreds of records.

After he had finished mixing the record and used a lathe to cut the lacquer, he showed me the grooves which has been cut using a microscope attached to the lathe. Not quite as much detail as the photos above, but more than enough to see clearly how the shape of the grooves creates the resultant waveform.

Really, really incredible feeling.

Vinyl records are, without a doubt, one of my favourite pieces of music technology.

I hue shifted the 3D one for blue/brown lenses incase anyone's interested.

http://i47.tinypic.com/2hr25go.jpg

Also, original link http://www.optics.rochester.edu/workgroups/cml/opt307/spr05/...

Free upvote to the first person who writes a program to play the waveforms directly from the scanned images... ;)

A modification to the process described at http://www.phys.huji.ac.il/~springer/DigitalNeedle/ could do it, but you'd get like a fraction of a second of decoded audio from the images on that page, so not that interesting.

Is the sound created by the change in the depth or the shape of the groove?

Shape of the grove. The needle is vibrated from side to side.

Both!

http://en.wikipedia.org/wiki/Gramophone_record#Stereo_sound

While the stylus moves horizontally when reproducing a monophonic disk recording, on stereo records the stylus moves vertically as well as horizontally. In fact, prior to the full development of the 45/45 system, the first stereo cutting heads were made by bolting together one lateral cut head and one vertical cut head sharing a common stylus holder. Feeding the driving coils with suitably phased material achieved the 45/45 groove.

I always wondered how stereo was achieved. God bless Wikipedia!

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