User's Guide ADI-648 © RME
11
7.4 Outputs MADI
At the rear side of the ADI-648 there are two MADI outputs.
The BNC output is built according to AES10-1991. The output's impedance is 75 Ohm. The
output voltage will be 600 mVpp when terminated with 75 Ohm. Using two DIP switches on the
rear of the unit, the output voltage can be increased to 1 Vpp and 1.5 Vpp. These settings are
not intended to be used in normal operation. But in case of a very long or 'lossy' coaxial cable,
these settings may ensure an error-free operation of the transmission line.
The optical output uses a FDDI (ISO/IEC 9413-3) compatible optical module, according to
AES10-1991. More information can be found in chapter 11.2, MADI Basics.
With the Matrix Router de-activated, all ADAT channels are copied to the MADI format in a
logical order:
ADAT In
1
2
3
4
5
6
7
8
MADI Out
1-8
9-16
17-24
25-32
33-40
41-48
49-56
57-64
When activating the 96k Frame mode, channel distribution changes as follows:
ADAT In
1
2
3
4
5
6
7
8
MADI Out
1-4
5-8
9-12
13-16
17-20
21-24
25-28
29-32
As the device internally always operates in Sample Split mode, the Matrix won't change its
functionality in Double Wire (Sample Split = Single Speed) and 96k Frame (Double Speed). In
both cases the number of channels is reduced to 28 or 32. At the same time the Matrix Router
no longer operates in 8-channel, but 4-channel blocks.
8. Clock Section
8.1 Clock Configuration
The unique ICC technology (Intelligent Clock Control) allows for a flexible use of both converter
units with internal clock (44.1 and 48 kHz, 88.2 and 96 kHz in DS mode), external word clock or
the digital input signals. All options are intelligently coupled and easily applicable and under-
standable, thanks to a clear display of the corresponding lock state.
As clock source, INTERNAL (crystal), EXTERNAL (BNC word clock) and INPUT (the digital
input signal ADAT/MADI) can be chosen. If the clock signal is present, the corresponding LED
will light constantly. If no signal is present, the LED will flash.
The ADI-648 can extract its reference clock directly from the MADI signal. In most cases an
additional word clock will not be necessary.
INPUT
As displayed on the front panel, the CLOCK SOURCE for the INPUT setting can be the ADAT
or MADI input. A missing or invalid clock source signal is indicated by flashing of the
corresponding LED.
EXT.
With EXTERNAL, the ADI-648's word clock input is used as clock reference. The LED will
flash, if the word clock is missing or unusable.
