Signal Connections - Alesis adat AI4 Reference Manual

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Signal Connections

Once you've got the AI4 safely mounted, it's time to cable in the rest of Once you've got the AI4 safely mounted, it's time to cable in the rest of
your gear. All connections are located on the back panel and fall into your gear. All connections are located on the back panel and fall into
three categories: three categories:
AES/EBU AES/EBU
AES/EBU is a standard digital connection used in many professional AES/EBU is a standard digital connection used in many professional
audio applications. Each AES/EBU line carries two channels of audio. audio applications. Each AES/EBU line carries two channels of audio.
You'll find AES/EBU connectors on outboard analog-to-digital You'll find AES/EBU connectors on outboard analog-to-digital
converters, digital mixers, DAT and CD recorders, and other high-end converters, digital mixers, DAT and CD recorders, and other high-end
digital audio devices. digital audio devices.
ADAT Optical ADAT Optical
Also known in the industry as "Lightpipe," ADAT optical is the most Also known in the industry as "Lightpipe," ADAT optical is the most
popular multichannel digital audio interface in the world. In addition to popular multichannel digital audio interface in the world. In addition to
support by all of Alesis' multitrack recorders, ADAT optical is widely support by all of Alesis' multitrack recorders, ADAT optical is widely
supported by digital mixers, computer audio interfaces, third-party supported by digital mixers, computer audio interfaces, third-party
multitrack recorders, and even synthesizers and samplers. multitrack recorders, and even synthesizers and samplers.
Word Clock Word Clock
Word Clock has been described as a sort of digital "metronome" that can Word Clock has been described as a sort of digital "metronome" that can
control sample timing. Although digital clock is transmitted over such control sample timing. Although digital clock is transmitted over such
connections as AES/EBU and ADAT Optical, some situations call for connections as AES/EBU and ADAT Optical, some situations call for
one central and stable clock. For example, if you're interconnecting more one central and stable clock. For example, if you're interconnecting more
than two devices, you can use Word Clock as a central master to ensure than two devices, you can use Word Clock as a central master to ensure
that all of the connected units are receiving the same clock information that all of the connected units are receiving the same clock information
at the same time. at the same time.
About Digital Audio
Formats
If you're new to digital audio
formats, there are a couple of
things you should know
before proceeding (experts
can skip this part). Each of
the AI4's connections is
designed to handle a specific
signal format; they're not
interchangeable with other
formats, despite the fact that
the connections may look
similar. The AES/EBU
connections, for example, use
the same XLR connectors as
balanced analog audio lines.
But these jacks are not
designed to handle analog
signal. Optical connectors
are sometimes used for
stereo S/PDIF digital
signals; again, the ADAT
Optical connectors on your
AI4 are not designed to
handle S/PDIF. Connecting
the wrong type of signal (for
example a +4dBu analog
line) can damage your AI4.
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