Laser Turntables

["George Brock-Nannestad" <gbn.av@xxxxxxxx>]

Hello, in particular to David A.Day,

Re: 13 January 2000 query.

there is no other laser turntable around that functions along the 
principle of the ELP (previously known as FINIAL). The turntable is 
excellent for all opaque record materials including shellac records, 
prvovided they have a approximately a 90 degree groove profile - 
this would cover all mechanical records made after ca. 1950. 
Laquers (acetates to some of you) fare less well because they are 
really quite transparent.

The advantage of this turntable is that there is no wear on the 
record. Special problems may need special turntables, such as the 
one from École Polytechnique de Lausanne which uses a trailing 
optical fibre as the stylus but which creates inherent distortions. 
However it may be either that or no reproduction at all from crazed 
laquer records.

Many tracking problems may be solved by half-speed replay and 
"ordinary" pick-ups (but then the archive world is not ordinary). Half-
speed may be difficult to achieve, but 33 1/3 from a 78 or 80 rpm 
record is equally good, only you need to change the speed back to 
the correct speed by some means, such as going via a PC.

Best regards,


George Brock-Nannestad 
(experienced in Audio Preservation, but a neophyte on this list)
Preservation Tactics (my consultancy)