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Re: [ARSCLIST] Can 78s sound better than LPs?



----- Original Message ----- 
From: "Richard L. Hess" <arclists@xxxxxxxxxxxxxxx>
> At 07:41 PM 8/27/2006, steven c wrote:
> >Any analog system (at least until when/if laser/optic players are
perfected)
> >will produce at least SOME noise when a recording is played...shellac
more
> >so because of the coarser "filler" included in the compound from which
the
> >records are made. In any case, as long as there is physical contact
> >between the playing device (usually "stylus") and the sound source,
> >there will be friction which in turn generates "noise." OTOH, photons
> >bouncing off of CD surfaces apparently don't generate any (audible?)
> >noise. One wonders, though, if these photons can, in theory, knock
> >molecules from the plastic surfaces (in which case, CD's might show
> >wear after a gazillion or so plays...?). The problem is, though, that
> >as each reduction in the physical size of the "stored information"
> >took place, the amount of damage needed to render the "record"
> >unplayable also became closer to invisibility!
> >(Side question...could a magnetic tape become useless if enough
> >oxide was removed from the layer thereof?)
>
> Steven,
>
> The difference between analog and digital is that until the noise
> gets to the point where there is an ambiguity in the numbers, the
> digital recording won't degrade. In analog, you're pulling the signal
> off the disc and amplifying it, noise and all.
>
> In the CD case, you're reading numbers. As long as you can accurately
> read the 44,100 numbers per second per channel then there will be no
> audible difference. There are error correction and error concealment
> algorithms to help you read the numbers accurately. This is why
> failure in digital is sometimes described as a "cliff effect".  For
> example, in digital video, this is a common design detail that must
> be addressed. Cable length is critical. At some point, if you add ten
> feet of cable, the line receiver will no longer deliver an error free
> interpretation of the code and you'll get a really bad signal. Until
> this cliff is reached, there is no degradation of the signal. The CD
> would work the same way.
>
> Magnetic tape can fail by losing its oxide. Oxideless base film is
> useful if  you need to tie up presents.
>
So, this reverts back to my original "I wonder"...if something is
bombarded with photons for a long-enough period, will it eventually
lose enough atomic/subatomic particles to alter its "shape?" Note
that this is a "nano-version" of record wear, where the stylus
removes some of the material of which the "record" is made each
time it is played!

The technical version of the question amounts to: "Object X is made
of <VERY large number> of atoms...how many of these atoms, or their
components, can be removed before there is a noticeable difference?!"

Either way, it's going to take a LONG time to prove/disprove...

Steven C. Barr
(Thanxes for answering my tape question...which, on more serious
thought, would refer to "sticky shed"...!)


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