Specifications

Chapter 3: Installing Pro Tools on Mac 27
Connecting an Additional 16 Channels
of Audio with Legacy I/Os
Each 192 I/O, 192 Digital I/O, and 96 I/O can
support 16 channels of audio to and from
Digidesign Legacy I/Os. (The 96i I/O does not
support Legacy I/O.) Legacy I/Os include the
888|24 I/O, 882|20 I/O, 1622 I/O, and the 24-bit
ADAT Bridge I/O.
To connect Digidesign Legacy I/Os:
1 Connect the “MIX card” end of the peripheral
cable that came with your Legacy I/O (60-pin
side) to the Legacy Port on the primary
Pro Tools|HD audio interface. Connect the
other end to the Computer Port on the Legacy
I/O.
2 Do one of the following:
• Connect any additional Legacy I/Os in the
same manner, to Pro Tools|HD audio inter-
faces connected directly to Pro Tools|HD
cards.
– or –
• If you are using a Y cable (Legacy 16-chan-
nel peripheral cable adapter), connect this
to the Legacy port first, then connect the
audio interface peripheral cables to Port A
and Port B of the Y cable.
3 To properly clock the Legacy I/O, connect the
Ext. Clock output port on the Pro Tools|HD I/O
to the Slave Clock IN on the Legacy I/O. The
Legacy I/O will switch to Slave mode once the
proper clock is outputting from the
Pro Tools|HD I/O. Always use the Ext. Clock Out
port of the same I/O to which the Legacy I/O is
attached.
If you are using the Y cable to connect multiple
MIX audio interfaces, you must also connect the
Slave Clock Out of the first Legacy interface to
the Slave Clock In of the second Legacy interface
with the provided BNC cable. You cannot clock
more than two MIX audio interfaces from a sin-
gle Pro Tools|HD audio interface. If you have a
third MIX audio interface, supply its 256x clock
from the Pro Tools|HD I/O to which its 60-pin
cable is attached (either your second audio inter-
face, or directly to an HD Accel or HD Process
card).
The original 888 I/O and 882 I/O interfaces
are not supported with Pro Tools|HD.
Optional 16-channel peripheral cable adapter
“A” to first
Legacy I/O
“B” to second
Legacy I/O
To Legacy Port on
Pro Tools|HD audio interface
To ensure the proper functioning of Legacy
I/Os (such as an 888|24 I/O or
882|20 I/O), launch Pro Tools and initial-
ize the Legacy I/Os in the Hardware Setup
dialog before turning them on (See “Config-
uring Legacy I/Os” on page 50). Then quit
Pro Tools and shut down your computer.
When relaunching your Pro Tools system,
turn on your Legacy I/Os first and allow
them to complete booting before turning on
your Pro Tools|HD audio interfaces, and
then your computer.
Before you turn on and configure your Leg-
acy I/Os, turn down the volume of output
devices. Very loud digital noise may be
emitted before the Legacy I/O is initialized.