[78-L] VARIABLE MICROGRADE 78

[David Lennick]

Did Columbia (pre-CBS) use what certainly looks like variable pitch on some 
records in 1938, or did they just have a faulty cutter? There are definite 
variations in the separation visible on some of the Orson Welles and Maurice 
Evans Shakespeare recordings (possibly some others), but you'd think this would 
require a dubbing source, to provide advance knowledge of when to apply it, and 
their recordings were still direct-to-disc at that time.

dl

On 5/6/2013 11:03 PM, Kristjan Saag wrote:
> Yes, I just saw that Joe S. already pointed this out a few days ago
> (about the pitch).
> Kristjan
>
> On 2013-05-07 03:51, Michael Biel wrote:
>> From: Kristjan Saag<saag at telia.com>
>>> The Variable Micrograde method, patented by Deutsche Grammophon in
>>> 1946, had nothing to do with variable pitch. It was the cutting
>>> speed that was varied, producing variable distance between grooves.
>>
>> There are Language problems here.  In Technical English, "Variable
>> Pitch" DOES mean variation in the distance between the grooving with
>> changes in lines-per-inch. "Cutting Speed" as you use it in this
>> circumstance would mean the variation in the rotational speed of the
>> feedscrew moving the cutter head forward.  When it turns faster the
>> grooving gets spaced wider apart, slower moves them closer together.  In
>> all instances the rotational speed of the DISC remains constant!!  Both
>> terms are leading towards the same result.
>>
>> Mike Biel  mbiel at mbiel.com
>>