User's Guide ADI-4 DD © RME
9
Notes on special functions
The second ADAT input (IN 2) can be selected as source of channels 1/2 by the key AES 1, in
case an optical SPDIF signal is present. This allows for example to convert the signal of a CD-
player into ADAT format. Of course, a simultaneous conversion of ADAT to AES is no longer
available.
If only one AES input is supplied with a valid signal, the ADI-4 DD switches to a distribution
mode. The input signal will then be copied to all 8 ADAT outputs (splitter 1 to 4).
6.3 Input State Display
The input state of the AES inputs is displayed by 9 LEDs. Every input has its own SYNC LED. If
SYNC is set to AES, a missing or invalid input signal is indicated by slow flashing of the AES
LED. As soon as a valid input signal is present the four SYNC LEDs will react per input.
If a valid input signal is applied, SyncCheck is active automatically. When more than one input
signal is present, the input with the lowest number serves as reference. If the AES input is not
chosen as clock source, SyncCheck takes the chosen clock (WC, ADAT) as reference and
compares it with the input clocks. Inputs which are not synchronous will be signalled by quick
flashing of the corresponding SYNC LED.
AES/EBU and SPDIF can contain an Emphasis information. Audio signals with Emphasis have
a strong high frequency boost and thus require a high frequency attenuation on playback.
Emphasis is not available within the ADAT standard! This information is thus neither passed
on to the ADAT output, nor taken into account later on for acoustic transmission!
Each channel's audio level is shown by a LEVEL LED. The green LED is lit as soon as one of
the channels of a 2-channel block contains audio data that is no longer digital zero.
6.4 Outputs ADAT Optical
The ADI-4 DD provides two digital outputs in ADAT optical format. In normal operation only the
output OUT 1 is used. When using more than the first 4 channels at activated DS (Double
Speed), the output OUT 2 also has to be used.
Both ADAT optical outputs always operate simultaneously and – as long as DS isn't active -
carry the same audio data. With this it is possible to distribute the output signal to two devices
(2 x ADAT splitter).
The ADAT optical outputs of the ADI-4 DD are fully compatible to all ADAT optical inputs. A
usual TOSLINK cable is sufficient for connection.
OUT 1
Interface for the first or only device receiving an ADAT signal from the ADI-4 DD. Carries the
channels 1 to 8. When sending a Double Speed signal, this port carries the channels 1 to 4.
OUT 2
Copy of the data at the output OUT 1. When sending a Double Speed signal, this port carries
the channels 5 to 8. When AES STATE OPT is selected, OUT 2 is used to send channels 1/2 in
SPDIF format.
