Clock Section - RME Audio ADI-8 DS Mk III User Manual

8.5 Clock Section

The source and frequency of the unit's clock is configured in the CLOCK section. The button
CLOCK lets you step through the options external clock (Word, AES, ADAT) and internal clock,
and sets the sample rate range for both an external and the internal clock.
WCK, AES, ADAT
Defines the corresponding input as clock reference. A missing or invalid clock source signal is
indicated by flashing of the corresponding LED.
INT (Master Mode)
Activates the internal clock.
With a setting of INT (internal clock) it is mandatory that the clock rate of the sources is
synchronous to the ADI-8 DS. Therefore the external device has to be synchronized to the
ADI-8 DS word clock output or AES/ADAT output.
The ADI-8 DS thus has to be master, all devices connected to it must be slave. In order to avoid
clicks and drop outs due to faulty or missing synchronicity, a special process called SyncCheck
compares the incoming data and the ADI-8 DS internal clock. The SYNC state is indicated by a
flashing (error) or constantly lit (OK) LED.
44.1, 48
Activates the internal clock at 44.1 kHz or 48 kHz.
DS, QS
With the DS LED additionally lit, the sample rate will be 88.2 or 96 kHz, with QS lit it will be
176.4 or 192 kHz.
A selection of DS and QS is also possible when
using external clock (Slave). If the ADI-8 DS should
operate at 192 kHz, but receives a synchronous
word clock of 48 kHz, the button STATE allows to
activate DS or QS mode. This way, AD-conversion
and digital outputs are configured to operate in the
frequency ranges Single Speed, Double Speed or
Quad Speed.
Using AES as clock source the STATE key is disabled, as the sample rate is clearly given by
the input signal. ADAT misses such information, therefore when ADAT is clock source the
STATE has to be set manually.
Single Speed
All outputs carry a signal in the range of 32 kHz up to 48 kHz.
DS (Double Speed)
The AES outputs 1-8 carry a signal in the range of 64 kHz up to 96 kHz. ADAT stays at no
higher than 48 kHz, with the data transmitted in the S/MUX format.
QS (Quad Speed)
The AES outputs 1-8 carry a signal in the range of 176.4 kHz up to 192 kHz. ADAT stays at no
higher than 48 kHz, with the data transmitted in the S/MUX4 format. Therefore ADAT is limited
to 4 channels (2 per optical output) in this mode.
User's Guide ADI-8 DS © RME
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