AJA Video Systems Inc ADA4 User manual

ADA4
4-Channel Bi-directional
Audio A/D and D/A
Converter
User Manual
February 14, 2006 P/N 101662-00
Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176 - FAX [phone] - TestEquipmentDepot.com

1
3
AJA ADA4 4-Ch Bi-directional Audio A/D and D/A Converter User Manual — Introduction
Introduction
The ADA4 is a 4 channel converter which can be configured as a 4 channel A/D, a 4
channel D/A, or 2 channel A/D and 2 channel D/A. The ADA4 can accept a AES11,
wordclock, or video sync/color black reference input for synchronization. Reference
input and synchronization is automatic. Audio levels are configurable via dipswitch
control.
Features
• Simultaneous A/D and D/A, or AES Synchronizer
• Full-time AES11 low jitter reference output
• Up to 4 channels of balanced analog to AES/EBU audio
• Up to 4 channels of AES/EBU to balanced analog audio
• Supplied XLR breakout cable
• AES11/Wordclock/Tri-level Sync/Color Black Reference Loop
• Adjustable Audio Levels
• Sample Rate Conversion Between 96KHz and 48KHz
• Dipswitch configuration
• 5-18VDC Power
Block Diagrams
ADA4, Normal Mode Block Diagram (Jumper 2 Installed), A/D or D/A
Audio
D/A
Audio
A/D
Audio
A/D
Audio
D/A
Clock
Gen
Analog Audio Ch. 1 or
AES/EBU Ch. 1/2 In
Analog Audio Ch. 3 or
AES/EBU Ch. 3/4 In
Analog Audio Ch. 2 In
Analog Audio Ch. 4 In
Analog Audio Ch. 1 or
AES/EBU Ch. 1/2 Out
Analog Audio Ch. 3 or
AES/EBU Ch. 3/4 Out
Analog Audio Ch. 2 Out
Analog Audio Ch. 4 Out
Reference Loop
AES-11 Out
Dipswitch 1
Dipswitch 2
Reference Loop
Output A
Output B
Output C
Output D
Input A
Input B
Input C
Input D

4
ADA4, Synchronizer Mode Block Diagram (Jumper 2 Removed), D/D
Audio
D/D
Audio
D/D
Clock
Gen
AES/EBU Ch. 1/2 In
AES/EBU Ch. 3/4 In
n/a
n/a
AES/EBU Ch. 1/2 Out
AES/EBU Ch. 3/4 Out
n/a
n/a
Reference Loop
AES-11 Out
Reference Loop
Input A
Input B
Input C
Input D
Output A
Output B
Output C
Output D

1
5
AJA ADA4 4-Ch Bi-directional Audio A/D and D/A Converter User Manual — I/O Connections
I/O Connections
ADA4 and Cable, Side View
Configuration
Determined by
DIP switch on
other side of
Converter
Audio I/O
AES/EBU Sync Output
BNCs
BNC
D-connector
(attaches to
supplied cable)
Cable
Not Shown
To Scale
+ 5 to 18VDC
Power
Input
Sync Input
Passive Loop
Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176 - FAX [phone] - TestEquipmentDepot.com

6
User Controls
The user interface for the ADA4 is a 4-switch DIP
accessible through a cut-out in the bottom of the
unit, and an internal 3-position jumper block
accessed by removing the ADA4 cover (secured by
4 screws). Use the jumper to configure the mode of
operation ( Normal or Synchronizer ).Then use the
DIP switches—if necessary— to configure
channels and audio levels.
The exact function of the jumper settings and each
DIP switch are described on the following pages.
Factory default switch settings are all in the
leftmost position.
Normal Mode
(Jumper #2
Installed)
Normal mode is the default operating mode of the ADA4 as shipped from the factory. In
Normal mode, the ADA4 performs A/D or D/A audio conversion as configured by the 4
DIP switches. In the factory Normal configuration, the internal jumper #2 is installed and
no jumper changes are required. DIP switch settings are discussed below:
Switch 1 (CH1/2: A/D or D/A)—Select type of conversion for
channels 1 and 2
:
Switch 2 (CH3/4: A/D or D/A)—Select type of conversion for
channels 3 and 4
:
1 2 3 4
DIP Switch Setting
LEFT RIGHT
LEFT RIGHT
Select Analog to Digital
Conversion
Select Digital to Analog
Conversion
LEFT RIGHT
Select Analog to Digital
Conversion
Select Digital to Analog
Conversion

1
7
AJA ADA4 4-Ch Bi-directional Audio A/D and D/A Converter User Manual — User Controls
Switch 3 (LEVEL)—Control whether audio levels are professional or
consumer; affects all inputs and outputs
:
Note:
Professional audio equipment has much higher levels than consumer equipment: a 0
VU reading corresponds to +4 dBu. Connecting a professional +4 dBu device to a consumer
audio input -10dBV (
-7.8 dBu)
may cause overloading, whereas the output of a consumer
device probably does not have sufficient power to drive a professional audio input. With
consumer and semi-professional audio equipment, a VU reading of 0 dB is typically
referenced to -10 dBV. 0 dBu = 0.775 VRMS.
Switch 4 (LEVEL)—Control whether audio levels are high or low;
affects all inputs
Output Level Selection Matrix For Switches 3 and 4
The following table shows the combinations of DIP switch settings required to configure the
audio output levels shown.
48 KHz/96KHz
Output Mode
(Jumper 1)
Jumper#1 selects how the AES outputs and and the AES11 reference output run. If Jumper 1
is installed, they run in 48 KHz mode. If Jumper 1 is removed, they run in 96 KHz mode.
LEFT RIGHT
Professional Level.
+4 dBu is typical of most
professional audio
(See Output Level Selection
Matrix Table)
Consumer Level.
-10dBV (-7.8dBu) is typical of most
consumer audio
(See Output Level Selection Matrix
Table)
LEFT RIGHT
High Level
(See Output Level Selection
Matrix Table)
Low Level
(See Output Level Selection Matrix
Table)
Output Level DIP Switch
#3
DIP Switch
#4
Audio Levels Pro-High: 0dBFS => +24dBu
LEFT LEFT
Audio Levels Pro-Low: 0dBFS => +18dBu
LEFT RIGHT
Audio Levels Consumer-High:
0dBFS => +12dBu
RIGHT LEFT
Audio Levels Consumer-Low:
0dBFS => +6dBu
RIGHT RIGHT

8
Synchronizer
Mode
(Jumper #2
Removed)
Synchronizer mode is an alternative operating mode where no audio A/D or D/A conversion
takes place. Instead, it allows for an AES input to be sample rate converted and reclocked to
reveal an AES output that is low jitter, and—when a reference signal is applied—locked to
reference. In this mode the DIP switches are ignored and all configuration options are set
via a 3-position jumper located inside the ADA4 case. To access this jumper, remove the
four phillips screws securing back side of the ADA4 case (the side having the DIP switch
access hole in it). Once the case cover is removed, you can easily identify the jumper by its
appearance. Jumper positions 1 through 3 are clearly marked on the circuit board next to
the jumper. Refer to the following diagram for jumper settings and their meaning.
ADA4, Internal Jumper Settings
Jumper 3 Jumper#3 is currently unused.
Lock LED
An LED is located next to the BNC connectors which shows the type of signal locked (if
any). Here are the meanings of the LED colors:
• Red = HD lock
• Green = SD lock
• Amber = AES-11 lock or Word Clock lock
Example: Normal mode selected.
Meaning: Jumper 2 installed—Normal Mode: Switches 1 and 2
independantly define A/D or D/A mode for their
respective pair of channels. Switches 3 and 4 are
used together to define the audio level.
Jumper 2 removed—Synchronizer Mode: Switches 1-4 have
no effect. The ADA4 is in D/D mode, with the output
re-timed to the reference signal, when applied.
Without a reference signal applied, the ADA4 re-
clocks the output based on its stable free-running
localoscillator.
Jumper 1:
123 Example: 96kHz output mode selected
(jumper effectively removed).
Jumper 2:
123
Meaning: Jumper 1 installed—48kHz: Any AES outputs and the AES-11
reference output are running in 48kHz mode.
Jumper 1 removed—96kHz: Any AES outputs and the AES-11
reference output are running in 96kHz mode.
Note: Jumper 3 is not used, but is provided as
a spare.
Jumper 3:
123Meaning: n/a: Jumper 3 is not used.
Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176 - FAX [phone] - TestEquipmentDepot.com

1
9
AJA ADA4 4-Ch Bi-directional Audio A/D and D/A Converter User Manual — Installation
Installation
Typically, ADA4 installation consists of the following:
1. disconnect +5VDC from the converter
2. configure the DIP switch for the desired equipment configuration
3. connect video equipment to the converter BNCs
4. apply +5VDC power to the converter (AJA power supply model DWP)

10
Specifications
Item Specification
Analog Audio I/O Balanced, XLR. One Channel per XLR connector.
AES Audio I/O Balanced 110 ohm, XLR. Two Channels per XLR
connector.
Analog Audio Levels (with Respect
to Full Scale Digital)
+24dBu (SMPTE RP155), +18dBu (EBU R68), +10dBV
(consumer +12.2 dBu)
Audio Converters 24 bit, 48/96 KHz
User Controls External Dipswitch:
Channel 1/2: A/D, D/A
Channel 3/4: A/D, D/A
Audio Level: Pro/Consumer
Audio Level: High/Low
Size 5.8" x 3.1" x 1 (147 x 79 x 25mm)
Power 5-18V, 3 watts. Requires power supply.
Reference Loop 75 Ohm (unterminated). HD/SD Sync, AES-11, or
Wordclock (48/96 KHz)

1
11
AJA ADA4 4-Ch Bi-directional Audio A/D and D/A Converter User Manual — Specifications
ADA4 Cable
pin 13
End View: Side View:
pin 1
pin 14
pin 25
pin 1
pin 2
pin 3
pin 1
pin 2
pin 3
Input A Input B
Input C Input D
Output A Output B
Output C Output D
ADA4
Channel Index
Input A Input B Input C Input D Output A Output B Output C Output D
= Analog Ch. 1 or AES Ch. 1/2 = Analog Ch. 2 = Analog Ch. 3 or AES Ch. 3/4 = Analog Ch. 4 = Analog Ch. 1 or AES Ch. 1/2 = Analog Ch. 2 = Analog Ch. 3 or AES Ch. 3/4 = Analog Ch. 4
Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176 - FAX [phone] - TestEquipmentDepot.com