Aes/Ebu Connections; Adat Optical Connections; Word Clock Input - Alesis adat AI4 Reference Manual

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Signal Connections

AES/EBU Connections

The AI4 uses standard XLR jacks for connecting to AES/EBU devices.
Cables should conform to the AES3-1992 specification: shielded
balanced lines with a nominal input impedance of 100 Ohms from
100kHz–2.288MHz.
The female jacks handle the incoming signal from AES/EBU compatible
units such as digital mixers, A/D converters, DAT decks and others; the
male jacks send outgoing signal to these same devices. Each AES/EBU
jack handles two channels of digital audio.
You can connect the output of S/PDIF devices to the AI4's AES jacks,
but these connections must still travel through a balanced line. We
recommend using an impedance matching transformer to prevent
reflections in the cable that can cause errors in the digital signal. S/PDIF
signals that are routed to an AES connection may still produce errors.

ADAT Optical Connections

The AI4's ADAT Optical connectors use the familiar TOSLINK-style
transmitters, but they are somewhat different from conventional
Lightpipe jacks.
Conventional ADAT Optical format can stream eight channels of 24-bit
digital audio signal per cable. This standard works extremely well with
sample rates of up to 48kHz. Examples of units using ADAT Optical
connectors include the Alesis ADAT family of modular multitrack
recorders; the Alesis ADAT Edit PCI computer audio interface; the
ADAT HD24 24-track hard disk recording system; and a host of third-
party digital soundcards, mixers, recorders, and A/D converters.
But in order for the AI4 to accommodate higher resolutions up to
96kHz, Alesis supports a "sample split" format that accepts four
channels of 24-bit/96kHz audio per cable.
You have two options in setting up the AI4 for ADAT Optical. For
signals with sample rates up to 48kHz, use the jacks labeled CH 1–8 (Ch
1–4). Signal coming from your source goes into the AI4's inputs; signal
returning to the source goes to the AI4's outputs.
If you're working with higher resolutions, you'll divide the signal between
two jacks. Route channels 1–4 to the CH 1–8 (Ch 1–4) jack; route
channels 5–8 to the second jack, labeled (CH 5–8).

Word Clock Input

In addition to routing and converting digital clock from any of the
AES/EBU or ADAT Optical connectors, the AI4 can convert and route
a master word clock to all connected digital audio devices. Connect the
word clock output of the master clock source to the AI4's 75Ω BNC jack
labeled World Clock In.
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