GRASS VALLEY 8911 AES-EBU, Instruction Manual

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8911 Instruction Manual

8911 AES/EBU Reclocking Distribution Ampli

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Functional Description

The 8911 has one loop-through, high impedance input and produces eight 
75-Ohm outputs. The AES/EBU data is reclocked by means of a phase-
locked-loop. Refer to 

Figure 1

 while reading the following description.

Figure 1.  8911 AES/EBU Reclocking DA Block Diagram

Input Section

The input channel is loop-through and is not terminated (the differential 
input is high impedance). The input signal comes from the 50-pin con-
nector, P1, and feeds a transformer, T1. Transformer coupling on the input 
eliminates common mode noise. The output side of the transformer feeds 
the differential line receiver of AES/EBU receiver U3. 

The AES/EBU receiver reclocks the data for its AES/EBU data stream. The 
mode pins 17, 18, 23 and 24 are set to pass the entire AES3 signal with the 
preamble. The receiver has an incoming audio sample frequency range of 
25 KHz to 55 KHz.

Output Section

After it is reclocked, the serial data is routed to a quad EIA-485 line driver, 
U4. The line driver chip drives eight output lines.

Phase

Locked

Loop

Input Section
AES/EBU Receiver
U3

Output Section   U4

Differential
Line Rx

Output
Line Driver

Output
Line Driver

AES 
Outputs

T1

0544_00

Reclocker

Loop-through

AES Input 

Lock LED