Specifications

HD I/O Guide10
AES/EBU [Encl]
These are balanced, three-conductor XLR con-
nectors that accept and output a stereo, 24-bit
AES/EBU audio signal. These two ports support
up to 192 kHz sample rates.
S/PDIF Digital In and Out
These are unbalanced RCA jacks that receive and
send two channels of S/PDIF audio. S/PDIF sup-
ports up to 24-bit audio, at sample rates up to
192 kHz.
Optical (ADAT) [Encl]
These Optical ports provide up to eight channels
of Optical (ADAT) input and output, or two
channels (stereo) optical S/PDIF input and out-
put. Optical (ADAT) mode supports sample rates
up to 48 kHz. Using S/MUX, these Optical ports
support provide up to four channels of Optical
S/MUX input and output at sample rates of 88.2
and 96 kHz, and up to two channels of Optical
S/MUX input and output at sample rates of
176.4 and 192 kHz. In TOS-Link mode, the ports
support two channels of Optical input and out-
put at sample rates up to 96 kHz.
About Lightpipe-Compatible Devices
Lightpipe is an industry standard, eight-channel
optical digital audio connection created by Ale-
sis. Lightpipe is found on many devices, includ-
ing Optical (ADAT) decks, modular digital mul-
titracks (MDMs), A/D or D/A converters,
S/MUX, and digital consoles.
DigiLink Mini Ports
PRIMARY PORT
Use the PRIMARY PORT to connect HD I/O to
your Pro Tools|HD system using a DigiLink Mini
to DigiLink cable (adapter included).
The Primary port sends and receives 32 channels
to and from a Pro Tools|HD card. Input and out-
put channels 17–32 (if active) are passed
through to the EXPANSION PORT.
EXPANSION PORT
The EXPANSION PORT lets you connect an ad-
ditional Pro Tools|HD audio interface to
HD I/O. The EXPANSION PORT passes input
and output channels 17–32 to the expansion (or
secondary) audio interface.
This port is only available when HD I/O is con-
nected to a Pro Tools|HD card (it is not available
when the HD I/O is connected to the Expansion
Port on another audio interface).
To maintain data integrity and minimize
jitter, use only 75-ohm coaxial cable for
S/PDIF connections.
Configure HD I/O for ADAT S/MUX on the
enclosed ADAT port and also on the ADAT
port on the Digital I/O card to get 8 chan-
nels at 88.2/96 kHz or 4 channels at
176.4/192 kHz.