LP acetate

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I'm told about a demo disk from 1963 that is not an "acetate" but a "vinyl
LP" (made independently for Columbia Records). There is little chance that
hundreds of this disk were made as in a typical 'pressing'.

He has handled many acetates so I guess he means it is on some black
semi-flexible plastic. I suppose it was cut directly on some kind of disk
not an acetate, but I'm guessing. Does anyone have a better guess what this
may be and what it is called?

[Adrian Tuddenham[_2_]]

> wrote:

> I'm told about a demo disk from 1963 that is not an "acetate" but a "vinyl
> LP" (made independently for Columbia Records). There is little chance that
> hundreds of this disk were made as in a typical 'pressing'.
>
> He has handled many acetates so I guess he means it is on some black
> semi-flexible plastic. I suppose it was cut directly on some kind of disk
> not an acetate, but I'm guessing. Does anyone have a better guess what this
> may be and what it is called?

Look at the edge of the centre hole, if the disc is nitrate-on-aluminium
(which is what many people incorrectly describe as 'Acetate') the edge
of the aluminium base material will usually be visible as a silvery
reflection. If there is an extra drive hole, that is a direct-cut disc
and not a pressing of any kind.

From the 1930s to the 1950s, other base materials such as glass were
occasionally used, but by the 1960s aluminium was the norm. In the
1960s, the coating material was usually nitrate lacquer (acetate was
impossible to cut without tearing, although it could be embossed in some
specialised recording systems) - be careful, nitrate is flammable.

If only a few copies were needed , the original disc would be processed
to give a metal 'master' and this would be used as a stamper to directly
press the required small number of copies. That was known as
'half-processing'; if many more copies were wanted, the full process of
Master-Mothers-Stampers-Pressings would be used so that the Master did
not become worn out.

Half-processed or full-proceed copies may show processing codes of
letters and numbers in the run-out area. If you understand the
individual company's coding system, you may be able to work out whether
full or half processing was used for that disc. Pressed discs never
have an extra drive hole, but there may be marks which show where
unwanted drive holes were stopped up before processing.

There were embossed recordings made in the 1960s, but they were usually
recorded in booths at railway stations or large department stores. I
have not heard of studio recordings made that way and the quality was
usually pretty dire. Those discs are often a sandwich of two softer
plastic layers on a harder plastic core; the core material is sometimes
coloured white and is visible at the centre hole.

Hope that helps.

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

[Scott Dorsey]

> wrote:
>I'm told about a demo disk from 1963 that is not an "acetate" but a "vinyl
>LP" (made independently for Columbia Records). There is little chance that
>hundreds of this disk were made as in a typical 'pressing'.

You can run a pressing run of ten discs. It's not really very cost-effective,
but folks will do it.

I don't know what the numbers were like in 1963, but today it's basically
around $250 plus the cost of having the lacquer cut to have a run of ten
discs with generic labels. They will be noisier than a run of a thousand
since the press may not be quite equalized in temperature on a short run.

>He has handled many acetates so I guess he means it is on some black
>semi-flexible plastic. I suppose it was cut directly on some kind of disk
>not an acetate, but I'm guessing. Does anyone have a better guess what this
>may be and what it is called?

It could well just be a normal test pressing. If there's no aluminum ring
on the outside, and it feels like a normal LP, that's probably what it is.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

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(Adrian Tuddenham) wrote:
(Scott Dorsey) wrote:


Wow! Big thanks to you for the swift and knowledgeable replies.
You've told me all I need to know.

I wish you a exciting and rewarding day.

/Dean