Re: [ARSCLIST] Longevity

[Jerome Hartke <jhartke@xxxxxxxxxxxx>]

CD and DVD error detection and correction algorithms will "play" discs with
2 mm diameter holes. Some DVD systems require a 6 mm defect before data loss
occurs, and the problem is then loss of servo lock by the read drive. Can
78s do this?

Jerry
Media Sciences, Inc.

> -----Original Message-----
> From: Association for Recorded Sound Discussion List
> [mailto:ARSCLIST@xxxxxxx] On Behalf Of Don Cox
> Sent: Saturday, July 01, 2006 9:23 AM
> To: ARSCLIST@xxxxxxxxxxxxxxxx
> Subject: Re: [ARSCLIST] Longevity
> 
> On 01/07/06, steven c wrote:
> 
> > Steven C. Barr
> > (one wonders what would happen if a CD were to be pressed in
> > shellac...or are the molecules too large to permit that...?)
> 
> I think polycarbonate is tougher and longer-lasting than shellac.
> 
> One reason shellac discs last well is the huge size of the grooves,
> compared to the dents in a digital disc. A scratch of a size that would
> be barely audible on a 78 can stop a CD from tracking.
> 
> It might be worth while to press some 78s in polycarbonate rather than
> vinyl.
> 
> The more information you pack in per square inch, the more easily it is
> damaged. Error correction helps but is not a cure-all.
> 
> Many users treat digital discs very carelessly.
> 
> Regards
> --
> Don Cox
> doncox@xxxxxxxxxxxxxx