Lynx Studio Aurora 16 - Manual (Page 16)

Page 14
2.6.3 SynchroLock
The Aurora incorporates SynchroLock clock synchronization technology to provide extreme tolerance
to noisy external AES/EBU and word clock signals while generating an ultra-low jitter clock. This
technology is especially useful for combating noise induced on cables in complex studio installations.
SynchroLock provides clock synchronization while insuring bit-perfect digital transmission. When the
Aurora is connected in an AES/EBU daisy chain, SynchroLock acts like a jitter firewall to prevent the
propagation of jitter to downstream devices.
By coupling statistical analysis with low-noise clock generation techniques, SynchroLock is capable of
attenuating jitter on incoming AES/EBU signals by a factor of 3000:1. Compare this to attenuation of
100:1 or less for professional quality analog phase-lock loops (PLL). SynchroLock can easily handle
AES/EBU signals with jitter levels in excess of 800 nanoseconds.
The SynchroLock sample clock is a two-stage system that is comprised of a fast-locking, wide-range
analog PLL and digitally controlled crystal-based secondary stage. Due to extensive number
crunching of the secondary stage, SynchroLock typically requires one to two minutes to achieve final
lock. While the secondary stage is working, the analog PLL loop maintains lock, but with much less
jitter attenuation than the secondary stage.
When the final lock state is achieved, the secondary stage is switched on line and becomes the system
clock source. In some cases this switching process may cause a momentary disruption in digital I/O.
Because of this, it is recommended that recording or playback not be started until the SynchroLock
LED is on solid (see Section 2.1 Front Panel Controls and Indicators, item
e ).
SynchroLock works on any external word clock signal. By default, SynchroLock is active when the
Sample Clock source is set to a clock source other than Internal. SynchroLock may only be disabled
by external control of the Aurora. When disabled, the front panel SynchroLock LED will NOT be
illuminated.
SynchroLock is capable of locking to word clock frequencies within +/- 100ppm of 44.1 kHz, 48 kHz,
88.2kHz, 96 kHz, 176.4 kHz, or 192 kHz. Signals that fall outside of the lock range will cause the
SynchroLock LED to flash. In this case, the analog PLL is active and will provide the system sample
clock. To re-engage SynchroLock, simply tap through the SYNC SOURCE options to return to the
original source.