"David Nebenzahl" wrote in message
s.com...
On 2/4/2009 10:49 AM John Williamson spake thus:


I've heard it a number of times over the years on first play of a vinyl
record, on both 33 and 45 rpm discs, and the pre-echo has always been
*exactly* one revolution ahead of the peak, both on the lead-in and
between tracks or in quiet passages. I'd put it down as an artifact of
either the material of the master deforming slightly while being cut, or
distortion of the plastic while the hot record was cooling after coming
out of the mould. Unless, of course, the feed reel on the tape deck being
used just happened to rotate at the same speed as the turntable.

The latter is much more likely. Can't see how the vinyl could deform that
much and still retain an accurate image from the mold.


I've met that as well, pre-echo exactly one revolution of the disc ahead. It
would seem to be a remarkable co-incidence if all tape spools revolve at
exactly 33 1/3rd rpm! I'm not sure that the fact that you don't understand
the process is important.

David.