DigiDesign SYNC HD Manual page 45

LTC and Clock Reference
LTC can provide both positional and clock in-
formation in the same time code signal. LTC can
be recorded onto and played back from an ana-
log track, or a VTR audio, address or cue track.
LTC cannot be read when the reference deck is
stopped, or playing back at slow or fast wind
speeds (roughly 10x playback speed). Pro Tools
will not lock until the LTC signal is close to play-
back speed.
While resolving to LTC as clock reference, the
SYNC peripheral provides five options to opti-
mize your system for different types of tasks.
This lets you choose between faster response (for
when fast lock-up time is critical), or highest
sound quality (during critical laybacks, for ex-
ample).
LTC Servo Gain
The Session Setup window provides a submenu
for LTC Clock Reference choices. The five
choices provide different servo gain settings to
reduce the effects of jitter when locking to linear
time code.
In Standalone mode, these settings are also
available from the front panel and from the
SYNC Setup software utility.
Clock Reference LTC options in Session Setup
Servo Gain settings include the following:
LTC 0 (fastest) Allows the quickest resolving to
incoming LTC, but with greater jitter. This is the
default setting, and should be used when fast
lock ups are critical.
LTC 1 Provides an intermediate fast setting.
LTC 2 (average) Offers a compromise of lock up
time and jitter quality.
LTC 3 Provides an intermediate slow setting.
LTC 4 (smoothest) Offers the lowest jitter from
LTC resolve, but can take six to ten seconds to
achieve full resolve. This setting is most appro-
priate when loading audio from an analog mas-
ter, where reducing or eliminating jitter is more
important than lock speed. When using this set-
ting, be sure to allow adequate pre-roll before
punching in.
To resolve a SYNC peripheral to Linear Time Code;
From Pro Tools:
In the Sync Setup section of the Session Setup
window, choose an LTC and Servo Gain setting
from the Clock Reference pop-up menu.
From the front panel:
Press the Clock Reference switch to select LTC.
1
Set the LTC Servo Gain from the front panel.
2
See "Servo Gain" on page 63.
From the SYNC Setup software utility
(Windows only):
Select Linear Timecode (LTC) from the SYNC
1
Setup Clock Ref pop-up menu.
Choose a value from the SYNC Setup LTC
2
Servo Gain Offset pop-up menu.
Chapter 4: Using SYNC Peripherals 39