Regarding reliably accurate bit-for-bit duplication: 

Optical media are ALWAYS read erroneously to a degree, but most of the
time these errors are correctable (and so are corrected prior to D/A).
Be sure to choose a device which will interpret the data and correct all
correctable errors before burning the "copy". This facility will allow
you to burn copies which have fewer errors than the original. If you
have CD analysing software or hardware you can test this by comparing
original and copy.

We've used standalone Odixion copiers which correct data prior to
burning copies, but I'm told they're no longer produced, unfortunately. 



-----Original Message-----
From: Association for Recorded Sound Discussion List
[mailto:[log in to unmask]] On Behalf Of Grant, Tyra
Sent: 13 October 2009 19:45
To: [log in to unmask]
Subject: [ARSCLIST] DVD/CD duplicators

I could use some help figuring out how to select a new CD/DVD duplicator
to burn reference or access copies of audio, video and text files
(legitimately, from digital content we have created).  I thought this
would be simple---go out and order a new duplicator (and maybe that's
all there is to it---if so, feel free to say so) but I'm seeing there's
a lot I don't know.  


So, here's what I think we want:


-the ability to duplicate CD and DVD reference and access copies (of
audio, video, text--i.e., bits).  Duplicate one at-a-time rather than
multiples---a fairly simple duplicator I'm guessing;


-reliably accurate bit-for-bit duplication.  Are there differences in
duplicators' abilities to do this?  Over time?


-the ability to handle most disc formats---i.e., be as universal as
possible to handle source DVDs, CDs, CDR, CDRW.  Does this request make
sense and, if yes, is it a reasonable request---any compromises involved


-We mainly use PCs but would like MAC platform compatibility also. Is
this possible or are we talking compromises and possibly should plan for
MAC or PC dedicated burners?



-Is there anything in particular to recommend purchasing a standalone
vs. computer-linked duplicator?  Are there standalone burners that can
also link-up with a computer?


-Do all duplicators write to disc the same way?  If not, are there
differences that make a difference?  Is bit rot a factor with DVDs or
CDs?  If yes, is there a useful and affordable way to measure the rate
of bit rot or is this foolishness?


-Should we be writing to one format---i.e., DVDs?---regardless of the
source format?  (Revealing my lack of background but I need to learn so
better to ask.)


-What about lightscribe?  This could be useful but could affect disc
longevity.  What does this do to the disc? Is it considered harmless or
not or don't we know?     


-Are there better duplicators or manufacturers? best DVD drives for
duplicators?  Not sure how to ask this.


-Anything additional I should be asking?  


I'll appreciate whatever information, advice or recommendations are


Tyra Grant


Head, Preservation Department

University of Kansas Libraries

Phone: 785-864-8951