Grass Valley NV7512 v.1.3 - Manual (Page 77)

NV7512 Audio Router • User’s Guide 67
2. Installation
Making Reference Connections
Making Reference Connections
The NV7512 provides timing reference connections for AES, MADI and video signals. Reference
connections provide a reference input for aligning incoming signals within the router.
AES Reference
The AES reference is used for clock generation and provides a timing reference for AES synchro-
nous signals and for the control card’s timing circuits. For optimum audio output, signals must be
clock-locked to the same reference. Input impedance is selected by setting jumper locations on the
control card. (See
Control Card Jumper Settings on page 85.)
The NV7512 has two AES reference connections labeled ‘AES REF 1’ and ‘AES REF 2’. Both
connections are used by the primary and the secondary (optional for redundancy) control card. This
provides a backup reference source should one of the sources fail. The AES reference connection
requires a stable signal source set at 48
kHz. For a detailed description of the AES reference con-
nections, see AES Reference Connections on page 18.
How to make AES reference connections
1 Locate the AES reference connections on the rear of the router, as shown in Figure 2-28. AES
reference connections are labeled ‘AES REF 1’ and ‘AES REF 2’.
Figure 2-28. AES Reference Connection (Rear View)
2 Connect to the ‘AES REF1’ connection using the connector and cable appropriate for the refer-
ence signal type:
For AES unbalanced signals, use a 75 W BNC connector and coaxial cable.
For AES balanced signals, use an 110 W Phoenix connector and twisted pair cable.
3 Connect the other end of the cable to a stable source of 48kHz AES audio signals.
4 For resiliency, connect to the ‘AES REF 2’ connection as described in Step 2.
5 Connect the other end of the cable to a stable source of 48
kHz AES audio signals.
MADI Reference
MADI reference connections are used when incoming MADI signals are at a different sample rate
than the AES reference (sample rate 48kHz). If no MADI reference is detected, the MADI signal is
locked to the AES reference sample rate. If a MADI reference is detected, the signal is locked to the
MADI reference sample rate.
The MADI reference provides the sample rate that drives a Sample Rate Converter sub-module on
the MADI input card used for asynchronous MADI signals (see
MADI (Unbalanced) on page 22).
If a Sample Rate Converter sub-module is installed, the MADI reference connections must be con-
nected. (See
MADI (Unbalanced) on page 22.)
AES
REF1
AES
Reference
AES
REF 2