[78-L] Record playing speed ^

[Michael Biel]

At 09:32 AM 12/3/2008, P G C wrote:


>> And is 160 rpm the standard speed for cylinders?
>>     
>
>   
Robert M. Bratcher Jr. wrote:
> Yes I suppose so but why did they go so fast instead of something like 80 rpm?
>
>   

In order to get enough surface speed on the small diameter cylinders 
they had to go faster.  Consider its size compared with the normal 
innermost groove on a disc.  The smaller cylinder at 160 just about 
equals the surface speed of the larger diameter of the disc's final 
grooving at half the rotational speed of 80 or 78.  The smaller size of 
the sapphire stylus on the cylinder also helps raise the upper frequency 
response possible, which helps because its surface speed is much lower 
than a disc at the outer edge or even the middle area of the disc.  The 
Concert and Salon cylinders had higher surface speed because their 
diameters were larger, but sometimes these ran at 120 or 144 instead of 
160.  These were the speeds that were also used on regular cylinders in 
the 1890s.  Dictating machines usually ran at 80 or 90 throughout their 
history.  They were also grooved differently than regular cylinders 
which were 100 per inch for 2-minute, and 200 for 4 minute.  Dictating 
machines were 150.
>>
>>
>> Ok there were 80, 78, 33 1/3 then 45 and even 16 rpm (my aunt had one of
>> these).
>>
>>     
Even these are not all of the standard speeds.  The earlier Berliners 
from 1890-92 or so ran around 90, especially the  5-inchers.  Then they 
ran around 70 or 72 in the early 7-inch days around 1892 to 94.  Since 
the machines were all hand-driven  you played them where they sounded OK 
(if they ever could).   The 14-inch Victor Special DeLuxe discs were 
labeled to run at 60 RPM.  The early center-start Pathe discs ran at 
90.  The GIANT 20-inch Pathe discs ran at 120 RPM.  Seeing one of those 
babies spin is amazing.  On the slow side, in addition to 16 2/3, there 
also was 8 1/3 which was used for Sound-Sheet magazines for the blind.  
16 2/3 was the usual speed for regular vinyl talking books for the 
blind, and also some 7-inch talking books that were sold to the public.  
Vox also used that speed for a short-lived series of music XLPs in 
1958.  In the 1930s, while the American talking books ran at 33 1/3 
using the RCA Program Transcription grooving until microgroove came 
along in 1948, in England there was another speed in the 40s, I 
believe.  I have a player for the blind with a Thorens motor that has 
that speed marked in addition to 33. 
>> But, is there a standard spining speed on a CD? (what does it mean 1X, 2X,
>> 16X, etc. in the CD-ROMS?)
>>
>>     
As partially mentioned in other posts, the CD and DVD are 
constant-linear-speed discs that start with faster rotation at the 
center and slow down as it goes towards the outer edge.  It's around 600 
to 200.   But recording machines and some players will over-scan and go 
faster, sometimes speeding up and slowing down while it reads or 
writes.  The Gray Autograph dictating machine and a broadcast logging 
machine in the 1940s, as well as the World record in England in the 
1920s were also constant-linear-speed records that varied rotational 
speed as the grooving diameter changed. 


Mike Biel  mbiel at mbiel.com