User Manual-for Windows

INSTALLING THE 828MK3 HARDWARE
24
Optical
The 828mk3 rear panel provides two sets of ADAT
optical (“lightpipe”) connectors: Bank A and B
(Figure 4-6). Each bank provides an input and
output connector. All four connectors can operate
independently and offer two different optical
formats: ADAT optical or TOSLink (optical S/
PDIF). For example, you could connect 8-channel
ADAT optical input from your digital mixer and
stereo TOSLink output to an effects processor.
The 828mk3 supplies +12dB of digital trim (boost)
for each optical input, which can be adjusted from
CueMix FX (“Input trim” on page 72) or the front
panel (“The IN (inputs) menu” on page 45).
Below is a summary of optical formats:
Optical operation at 44.1 or 48 kHz
When configured for ADAT “lightpipe”, an optical
connector provides 8 channels at 44.1 and 48 kHz.
ADAT optical operation at 88.2 or 96 kHz
When configured for ADAT “lightpipe”, an optical
connector provides four channels at 88.2 or 96 kHz
(2x sample rates). When using the ADAT lightpipe
format at a 2x rate, be sure to choose either Type I
or Type II operation, as explained in “ADAT SMUX
Type” on page 44.
Using optical I/O to operate the 828mk3 as a
16-channel expander
When the 828mk3 is not connected directly to a
computer via FireWire, the sixteen optical output
channels can be programmed (via the CueMix FX
mixer) to mirror the incoming signal on any
combination of the 828mk3’s inputs. By
connecting the 828mk3 optical outputs to another
device, such as another ADAT-optical equipped
interface or a digital mixer, you add up to sixteen
additional inputs to your system (or eight inputs at
the 2x sample rates).
To learn how to program the 828mk3 when it is
operating as a stand-alone expander in this
fashion, see chapter 6, “Front Panel Operation”
(page 41).
Choosing a clock source for optical connections
When connecting an optical device, make sure that
its digital audio clock is phase-locked (in sync
with) the 828mk3, as explained in “Making sync
connections” on page 28. There are two ways to do
this:
1. Resolve the optical device to the 828mk3
2. Resolve the 828mk3 to the optical device
For 1), choose Internal (or any other clock source
except ADAT optical) as the clock source for the
828mk3 in MOTU Audio Console.
For 2), choose either ADAT Optical A or ADAT
Optical B as the 828mk3’s clock source
(Figure 4-9). Be sure to choose the optical port that
the device is connected to.
Figure 4-9: Resolving the 828mk3 to an optical device.
For details about using the clock source setting and
the MOTU Audio Console software in general, see
chapter 5, “MOTU Audio Console” (page 35).
Using word clock to resolve optical devices
If the optical device you are connecting to the
828mk3 has word clock connectors on it, you can
use them to resolve the device to the 828mk3,
Format 44.1 or 48 kHz 88.2 or 96 kHz
ADAT optical 8 channels 4 channels
TOSLink stereo stereo
!828mk3 Hyb Manual/Win Page 24 Monday, March 28, 2011 6:11 PM