On Wed, 19 Nov 2008 18:11:02 -0500, "Arny Krueger"
wrote:

"Don Pearce" wrote in message
net
Arny Krueger wrote:
"Arny Krueger" wrote in message

"Don Pearce" wrote in message
et
Arny Krueger wrote:

http://delback.co.uk/turntable_tests/
For grins, you might try to extract some frequency
response information from them.

The Linn Sondek in that last link has the most fearsome
wow (about 0.3% RMS) - bad enough to be a real fault, I
think.

Correct that. The predominate jitter frequency seems to
be 0.55 Hz - off-center record.

A test record shouldn't be able to go off-centre. All of
mine are drilled small, and are a very tight fit on the
spindle.

Who says that the hole was necessarily drilled or punched in the right
place?

Where else do we get 0.55 Hz FM from?


Well, that's the wow. The raison d'etre of a test record is that it is
in itself far better than what you are testing. If we can't trust the
makers even to put the hole in the middle we may as well all give up
right now.

d