Manual-
Calibrating Scratch
LIVE
The TTM 57SL interprets the signal on record and communicates with the software. The signal needs to be clear for Scratch
LIVE
to
perform well. This section describes how to calibrate Scratch
LIVE
to optimize reading the control signal from your turntables or CD
players.
For best results, re-calibrate Scratch
LIVE
each time you move or make changes to your DJ equipment. To calibrate Scratch
LIVE
,
go to the
setup
screen by pressing the button at the top of the main screen, to the right of the Scratch
LIVE
logo.
Audio output
By default the output of Scratch
LIVE
is
stereo
. You can also select
mono
output. This setting is saved when you exit Scratch
LIVE
.
Signal threshold
The first step is to set signal threshold. There is always a certain amount of background noise, particularly when using turntables in a
club environment. With a normal turntable setup, this background noise is transmitted through the body of the turntable and platter
to the stylus, and can cause stylus feedback. In Scratch
LIVE
, this can cause the errors on the reading of the position and velocity of
the control record.
Place the needle on the record
with the record stopped
. Click the
estimate
button to measure the background noise and esti-
mate the appropriate threshold. Moving the threshold slider to the left will make Scratch
LIVE
more sensitive to slow record move-
ment, but also more sensitive to background noise.
Tip: If the slider jumps to the far right, then you have a problem with noise in your turntables/CD players/mixer. Check all your
connections and make sure your equipment is well earthed. In some situations you will not be able to improve the signal quality, and
you will have to play on regardless. In this situation, stick to
rel
mode. (See page Manual-19 for details)
Scope view
Once you have set the threshold, start both turntables. You will see green rings appear in the scope view, as shown below.
For optimal performance the inner ring should be as close to circular as possible. Use the scope zoom slider (
1x
to
16x
) to zoom
in or out as necessary. Use the scope
L/R balance
and
P/A balance
controls to adjust the shape of the inner ring.
The number in the top left corner of the scope view gives the current absolute position within the control record or CD. The
number in the top right corner is the current speed in RPM. In the bottom left is the current threshold setting, and the number in
the bottom right shows the percentage of readable signal – this number should be 100% when your system is calibrated properly.
Tip: If you have trouble getting the rings circular, you probably need to clean or change your needles. If the image appears as a
line, then one of the channels of the turntable is not working. See examples of potential problems and fixes on pages Manual-23-24.
