In article ,
Don Pearce wrote:
On Thu, 12 Mar 2015 12:14:10 +0000 (GMT), Jim Lesurf
wrote:

Just to let people know I've done some tidying and added a page to the
Audiomisc site.

http://www.audiomisc.co.uk/HFN/LPqua...denWonder.html

The new page looks at the changes in quality of LPs over the years.

All being well I plan to add another page or two soon on other topics.

Cheers,

Jim

A couple of things come to mind. At some point the vinyl got a lot
thinner - presumably a cost saving measure - and flatness suffered. A
particular kind of unflatness back then was the double "thumb and
finger grip" warp in the edge caused by manual removal from the press
while the plastic was still a bit too warm.

I suspect that along with that they also pressed the groove less deep into
the vinyl. Thus allowing shallower surface scratches to cause audible
clicks. Deeper grooves keep the points of stylus contact lower, away from
the surface. But take longer and need more vinyl. So cost more.

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
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