Dallas Hinton:

> AS> The disk can also be made of shellac, which, although
> AS> noisier, has its advantages.
>
> It could also be made of platinum which was used when pressing
> records, but both types are very rare these days!

For aught I know, recording was made by a lathe, originally driven
directly by the acoustic signal, and later by an electric amplifier.
One or more metal "matrices" were made from this disk by the
process of galvanoplastics. These matrices were then used in
"printing" shellac and vinyl disks. Unlike magnetic tape, these
disks do not deteriorate over time (but because of wear) and
usually contain a more direct and transparent presentation of the
sound that was heard in the studio, because tapes were often heavily
abused during mastering and mixing.

I never knew whether those platinum disks, awarded to musicians,
were really playable on the turn-table. If they are, it is new
source for the remasterers of old records: bettern than both
deteriorated tape and worn-out vinyl...

The movie "Two sisters from Boston" has a good enactment of the
natural recording process, but somebody has removed it from Youtube.

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