Lynx Studio Hilo Reference A/D D/A Converter System - Owner's Manual with LT-USB - Manual (Page 26)

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3.4.2 Sync Source
This button will show the currently selected Sync Source.
When you push the Sync Source button, you may select any of six possible clock
sync options. If a clock source is valid, a sample rate will appear next to that
selection. For instance, if a clock source is connected to the Hilo word clock input,
next to “Word Clock” there would appear the sample rate that the clock source is
generating.
When the LT-USB is NOT connected to the computer, the Sync
Source may be changed to one of the following four choices:
• Internal: Clock driven by the Hilo’s crystal oscillator
• Word Clock: Clock derived from the WORD CLOCK
input
• Digital: Clock derived from the active digital input
• ADAT In: Clock derived from the ADAT input. Once an
ADAT signal is detected on the Optical Input, Hilo
automatically switches the Optical input from S/PDIF to
ADAT. In this mode, the additional ADAT inputs will
appear as available channels on the output mix routing
page; meter source selection and the test tone page.
Please note that Word Clock/2 and Word Clock/4 are not available in version 5 firmware.
The box next to each clock source will display the clock rate when that port has a valid clock source attached. If that
clock source is selected, that rate will become the current clock rate for Hilo. If Hilo detects that a specific Sync Source
is not valid, that Sync Source button will be disabled and “Not Present” will be displayed next to it.
Please note: when Hilo is connected to a computer via USB, Sync Source can only be changed by disconnecting the
USB cable. In this state the SYNC SOURCE button is crossed out, indicating a disabled parameter.
3.4.3 SynchroLock
Lynx’s SynchroLock™ technology is a very effective form of jitter reduction for
digital signals. Jitter is a type of clock error that may potentially result in distortion in
an audio signal. SynchroLock reduces jitter by a factor of 3000:1 by using the Hilo’s
high resolution crystal oscillator to generate a clock signal that is phase locked to the
external clock.
Compare this to attenuation of 100:1 or less for professional quality analog phase-lock loops (PLL) that are used by
most Pro Audio devices. As long as the clock frequencies are within +/- 100ppm of Hilo’s supported sample rates,
SynchroLock will operate on the clock signal, and insure a low-jitter clock drives the Hilo and is also sent to devices
downstream (i.e. clock slaves to the Hilo).
The SynchroLock operation is a two-stage process, starting with a fast-locking analog PLL to insure that there is clock
sync immediately when a Sync Source or Sample Rate are selected, and concluding with the digitally controlled
crystal-based secondary stage. It is normal for SynchroLock to take 1-2 minutes to achieve full lock.