[ARSCLIST] Archiving CLV versus CAV transfer

[Eric Jacobs <ericj@xxxxxxxxxxxxxxxxxxx>]

Here's a question for those of you who deal with CLV (constant linear
velocity) groove recordings such as Gray Audograph or Memovox.  When making
a digital transfer of these CLV recordings using a conventional CAV
(constant angular velocity) turntable, which file transfer do you archive?

Do you archive the raw CAV transfer?  This CAV version is nearly
unintelligible as the pitch changes dramatically from start to finish.

Do you archive the processed (re-pitched CAV-to-CLV conversion) file?  The
re-pitched (but pre-EQ) file is intelligible.

>From a purist point of view, archiving the raw CAV transfer would seem best
on the face of things.

However, knowledge of the original machines is required to make the
CAV-to-CLV conversion.  If hum or other known constant FM or AM signal is
not present or easily identified on the disk, re-pitching becomes a guessing
game without knowing the speeds of the original recording machine as well as
the lead-in and lead-out groove radii.  So it would seem that it might be
better to make the CAV-to-CLV conversion (flat transfer, no EQ) and archive
that file while that knowledge and data is available.

If cost and disk space were not an issue, one could store both the raw CAV
transfer, as well as the CAV-to-CLV converted transfer.  But if cost and
space are an issue, which transfer would you preserve?

Eric Jacobs
The Audio Archive