XTA DS8000/D - Manual (Page 19)

Page 19 DS8000 Operator’s Manual
ta x
Lock LED operation
When sync is set to external, the lock LED beside the BNC socket will become active. It will
be illuminated when a valid clock signal is being received, and flashing when an external
clock is present but at an incorrect rate. If it is not illuminated then no signal is being
received.
Single flashing indicates external clock at an incorrect sample rate — 5% tolerance for the
normally accepted sample rates (so 48/96/192). Unit will switch to internal sync under these
circumstances to prevent loss of audio.
Double flashing indicates locking to a clock that is outside the 5% tolerance for the normally
accepted sample rates (so 48/96/192) — this is known as permissive mode and is explained
below.
Permissive Clock Mode
When sync is set to external, the DS8000 will only lock to an external wordclock if it falls
within close tolerance of a standard professional sample rate — so 48kHz, 96kHz or 192kHz,
+5%.
Default setting as shipped is Permissive Mode OFF.
Should there be a requirement to support a non-standard professional rate (such as 44.1kHz
or 88.1kHz), permissive clock mode can be enabled which will permit synchronisation from
32kHz up to 224kHz.
This selection is made by adjusting the link on the digital option PCB as show below.
Note: In this mode, the output sample rate will exactly follow the external wordclock sample
rate — we recommend only enabling this mode if it is explicitly required, to avoid confusion
and synchronisation problems “downstream” from the unit.