[78-L] One or three holes?

[Milan P Milovanovic]

Thank you so much for explanation!

Best wishes,

Milan


----- Original Message ----- 
From: "Graham Newton" <gn at audio-restoration.com>
To: "78-L Mail List" <78-l at klickitat.78online.com>
Sent: Thursday, June 30, 2011 1:51 AM
Subject: Re: [78-L] One or three holes?


> Milan P Milovanovic wrote:
>
>> not so while ago, the discussion about details of lathes raised. I came
>> across this record sample
>
>> http://youtu.be/tc2FrjRa9Os
>>
>> It is clearly visible only one hole mark besides spindle. I always
>> thought that one additional hole on lacquer was reserved for amateurish
>> type media and three additional holes for professional blank samples.
>>
>> Someone knows what's in case here? Why is there only one? Could it be
>> possible that recording engineers used semi pro or amateur recording
>> blanks?
>
> It depends on the type and design of the recording lathe.  The extra hole 
> or
> three holes are drive holes to engage with a single (usually spring 
> loaded) pin
> to prevent the lacquer disc from slipping as it is being cut for the 
> master.
> Why some lacquers were supplied with three holes is a mystery, since I 
> never
> encountered anything where more than one hole was needed.
>
> All home use disc cutting machines used discs with at least one drive 
> hole.
>
> Many professional mastering lathes like Scully and Neumann used lacquers 
> with
> no drive holes, only the center pin, and it was hollow to allow vacuum to 
> be
> conducted under the turntable platter to hold the lacquer flat while it 
> was
> being cut.
>
> Lathes like Presto, RCA Victor and others found in broadcast studios 
> mostly
> used lacquers with the drive hole since it was much cheaper to make a
> non-suction-hold-down turntable.
>
>
>
>
> ... Graham Newton (RCA Victor disc mastering engineer in a former life!)
>
> -- 
> Audio Restoration by Graham Newton, http://www.audio-restoration.com
> World class professional services applied to tape or phonograph records 
> for
> consumers and re-releases, featuring CEDAR's CAMBRIDGE processes.
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