[78-L] One or three holes?

[Robert M. Bratcher Jr.]

I saw a few 7" Audiodiscs with no label on them several years ago & all had the proper 45 rpm center hole.


From: David Lennick <dlennick at sympatico.ca>
>To: 78-L Mail List <78-l at klickitat.78online.com>
>Sent: Thursday, June 30, 2011 2:26 PM
>Subject: Re: [78-L] One or three holes?
>
>By the way, there WERE 7-inch lacquer blanks made by Soundcraft with a 
>punchable center hole for the 45 spindle..found an ad for them in a 1953 High 
>Fiddledeedee.
>
>dl
>
>On 6/30/2011 3:17 PM, Martin Fisher wrote:
>> Three holed urban legend.  These are erroneously referred to as "punch
>> marks" by misinformed Elvis devotees who believe the pressing machine made
>> them while extracting the finished 45 rpm records!
>>
>> Tee hee
>>
>> MF
>>
>> -----Original Message-----
>> From: 78-l-bounces at klickitat.78online.com
>> [mailto:78-l-bounces at klickitat.78online.com] On Behalf Of Milan P
>> Milovanovic
>> Sent: Thursday, June 30, 2011 2:08 PM
>> To: 78-L Mail List
>> Subject: Re: [78-L] One or three holes?
>>
>> 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!)
>>>
>