One central thought at the British Library National Sound Archive is to have
at least two copies of recordings. One is the 'archive copy'. This may be
the original recording or it may be a copy (or clone) of the original and is
as faithful to the original as is practical. The other version(s) is the
'playback copy' made for access or for conservation reasons. This version
may have been 'adulterated' with CEDAR, filtration and equalisation, editing
etc. In some cases the playback copy is identical to the original.
Sometimes there is no need to make a playback copy (we may have, for
instance, two copies of a published compact disc). Sometimes there are more
than one versions of a playback copy, perhaps reflecting 'layered'
techniques or improving technology. The transfer engineer making the
playback copy is required to document the process gone through to arrive at
the copy and this sound will embody the experience (both technical and
cultural) of the engineer. In any case, we always have the archive copy to
make other playback copies if required. It is worth noting that some of our
listeners and customers prefer the original sound (as Peter Copeland, my
predecessor, puts it "warts and all").