Specifications

SYNC I/O Guide42
SYNC I/O will only output rates within the lim-
its of the current sample rate. If a varispeed
value results in an output frequency (sample
rate) that is below or above the limits for the
current sample rate, the frequency display turns
red.
3 Click Set.
Using Pitch Memory
Pitch Memory holds the output sample rate
steady even when the Clock Reference is un-
available or has gone out of lock range.
◆ When Pitch Memory is not enabled, the out-
put sample rate would return to the nominal
sample rate setting (for example, exactly
44.1 kHz) when the Clock Reference disappears
or goes out of lock range.
◆ When Pitch Memory is enabled, Pro Tools
continues to play and record at the resolved
sample rate even if the Clock Reference source
disappears.
To configure Pitch Memory:
From the front panel:
1 Press Set, and use the Up or Down switches to
display Pitch Hold (PICH HLd).
2 Press Set. The LED Time Code Display shows
On or Off.
3 Press Up and Down to toggle between On and
Off.
4 Press Set.
From SYNC I/O Setup software utility
(Windows only):
■ Click Pitch Memory Enabled.
SYNC I/O retains the Pitch Memory setting,
even when the unit is powered off and on again,
until you change it.
Positional Reference
and Options
The following sections provide additional infor-
mation for each available Positional Reference
format.
Linear Time Code (LTC)
LTC is often striped onto an ATR or VTR audio
track. Professional VTRs typically have an ad-
dress or cue track, intended for LTC. If you are
working with a standard audio tape, you’ll al-
most certainly be working with LTC. If you’re
working with a videotape, you may be able to
work with either LTC or VITC, or both.
LTC can also be generated as an interpolation of
Absolute code. This is how time code DAT ma-
chines, DA-88, and many digital VTRs work. In
any case, LTC is delivered to SYNC I/O as a series
of audio pulses, regardless of how it is stored or
generated.
LTC can function simultaneously as a positional
reference and a clock reference.
To use LTC as SYNC I/O’s positional reference:
From Pro Tools:
■ In the SYNC Setup section of the Session
Setup window, choose LTC from the Positional
Reference pop-up menu.
From the front panel:
■ Press the Positional Reference switch to select
LTC.
From SYNC I/O Setup software utility
(Windows only):
■ Select Linear Time Code (LTC) from the
SYNC I/O Setup Positional Ref pop-up menu.