Date: Mon, 22 Jun 2009 11:23:26 -0700
From: Michael Biel <mbiel@xxxxxxxxx>
Subject: Re: (Fwd) [ARSCLIST] Fwd: Recording Speed
I understand what George is saying partially because I've seen him
do it
and I am lucky enough to have one of his calibration discs. In case
Doug and others still do not understand it, Doug's snip cut out the
important info and left in material that has no meaning without the
snipped part. =20
In 1982 George commissioned a 7-inch pressing made of a 450 Hz.
tone cut
at 45.0 RPM. That disc can be played at any RPM and a frequency
counter
will show a reading that is 10 times that RPM. (Play it at 73.7 RPM
and
it shows 737.0 Hz. 78.26 shows 782.6 Hz. Etc.) If you have a
frequency
counter handy, you can find what rotational speed you are using. BUT,
if you include a few seconds of that calibration disc played on the
same
turntable at the time of your transfer of the record you are
working on,
then later on that frequency can be read with a counter and at any
time
you can establish the rotational speed you used. It's like an audible
strobe disc that has the unique ability to be recorded, and it is as
accurate as your frequency counter is. Sure, you could use a normal
test disc of, say, a 1000 Hz. tone, but George's disc is more directly
readable without using math to have to determine percentage of 1000
Hz.
whatever tone you used.
Mike Biel mbiel@xxxxxxxxx =20