Optical Expander Mode - MOTU 828 User Manual

Optical Expander Mode

8
CHAPTER
OVERVIEW
The 828 has the ability to function as an optical
expansion interface. You can connect it to other
optical-equipped devices to route the 828's analog
inputs and outputs to and from the other device.
Up to 16 channels are supported at 1x sample rates
(44.1 or 48 kHz) and 8 channels at 2x rates (88.2 or
96 kHz).
Optical Expander mode supports the ADAT
format for both Bank A and B. TOSLink is not
available in Optical Expander mode.
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Making connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Enabling Optical Expander Mode . . . . . . . . . . . . . . . . . . . . . . . 63
Setting the sample rate. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Setting the Clock Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Channel mapping at 1x. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
MAKING CONNECTIONS
To route the 828's analog inputs to the other
device, connect the 828 Optical OUT A port to the
other device's Optical IN port. If the other device
has a 2nd bank of optical, connect the 828's
Optical OUT B to the other device's 2nd Optical
IN bank.
to route audio from the other device to the 828's
analog outputs, connect the other device's Optical
OUT to the 828's Optical IN A port. Similarly, if
the other device as a 2nd bank of optical, connect
it's 2nd Optical OUT bank to the 828's Optical IN
B port.
ENABLING OPTICAL EXPANDER MODE
You can enable Optical Expander mode using the
front panel LCD menu or the CueMix 5 device tab.
Figure 8-1: Enabling Optical Expander mode.
SETTING THE SAMPLE RATE
Be sure that the sample rate setting (item #2 on
page 43) for the 828 matches the sample rate of the
other device. At the 1x sample rates (44.1 and 48
kHz), each optical bank provides 8 channels. At
the 2x rates (88.2 and 96 kHz), each bank provides
4 channels.
SETTING THE CLOCK SOURCE
In Optical Expander Mode, the 828 transfers
digital audio channels over it's optical
connections. It is therefore crucial to make sure
that the clocks in the two devices are properly
resolved. See the following sections for further
information:
"Synchronization" on page 29
"Syncing optical devices" on page 30
63