Sonifex Redbox RB-ADDA2 Instruction Manual

Manufacturers of audio & video
products for radio & TV broadcasters
Redbox
User Handbook No 1
HANDBOOK
RB-ADDA Combined A/D and D/A Converter (24 bit, 96kHz
Capable) (1U)
RB-ADDA2 Combined A/D and D/A Converter (24 bit, 192kHz
Capable) (1U)
RB-SC1 Sample Rate Converter (24 bit, 96kHz Capable)
RB-SC2 Dual Sample Rate Converter (24 bit, 192kHz
Capable)
RB-DAC1 Digital to Analogue Converter
RB-SP1 Digital Splitter & Combiner
RB-SYA Analogue Video Sync Board For RB-SC2 (PAL,
NTSC, SECAM)
RB-SYD Digital Video Sync Board For RB-SC2 (HD-SDI,
SD-SDI)
RB-SYE AES/EBU Sync Board For RB-TGHD(B or X)
RB-SYW Word Clock Sync Board
RB-DS2 Stereo Delay Synchroniser & Time-Zone Delay
(1U)
RB-DS2R Remote Switch Panel For RB-DS2 (1U)
RB-PD2 Stereo Profanity Delay (1U)
RB-DD4 4 Channel Digital Audio Delay Synchroniser (1U)
RB-AEC Acoustic Echo Canceller (1U)

Redbox Handbook 1
This handbook is for use with the following product:
Redbox User Handbook No 1
Stock Code: 30-335
Artwork: AW10838
Revision 3.05, September 2019
©Sonifex Ltd, 2019
All Rights Reserved
Sonifex Ltd, 61, Station Road, Irthlingborough,
Northants, NN9 5QE, England.
Tel: [phone]
Fax: [phone]
Email: [email protected]o.uk
Website: https://www.sonifex.co.uk
Information in this document is subject to change without notice and does not represent a
commitment on the part of the vendor. Sonifex Ltd shall not be liable for any loss or damage
whatsoever arising from the use of information or any error contained in this manual.
No part of this manual may be reproduced or transmitted in any form or by any means, electronic
or mechanical, including photocopying, recording, information storage and retrieval systems, for any
purpose other than the purchaser’s personal use, without the express written permission of Sonifex
Ltd. Unless otherwise noted, all names of companies, products and persons contained herein are
part of a completely fictitious adaptation and are designed solely to document the use of Sonifex
product.
Made in the UK by
For the latest Sonifex handbook information please visit the
Sonifex website at www.sonifex.co.uk

Contents
Contents
Product Warranty - 2 Year Extended ii
Sonifex Warranty & Liability Terms & Conditions ii
1. Definitions ii
2. Warranty ii
Unpacking Your Product iii
Repairs & Returns iv
Conformity iv
Safety & Installation of Mains Operated Equipment iv
Voltage Setting Checks iv
Fuse Rating iv
Power Cable & Connection iv
WEEE Directive v
Atmosphere/Environment v
Fitting Redboxes v
1 RB-ADDA Combined A/D and D/A Converter 1
Introduction 1
System Block Diagram 2
Front Panel Indicators 2
Rear Panel Connections and Operation 2
Technical Specifications RB-ADDA 6
2 RB-ADDA2 Combined A/D and D/A Converter 24bit 192kHz 7
Introduction 7
System Block Diagram 9
Front Panel Controls & Indicators 9
Rear Panel Connections and Operation 10
Serial Port Control 12
Serial Interface Commands and Responses 12
Upgrading Firmware 14
Technical Specifications RB-ADDA2 14
3 RB-SC1 Sample Rate Converter 16
Introduction 16
System Block Diagram 16
Front Panel Indicators 17
Rear Panel Connections and Operation 17
Technical Specifications RB-SC1 19
4 RB-SC2 Dual Sample Rate Converter 21
Introduction 21
Installing the Optional Video Sync Boards 23
Opening the RB-SC2 23
System Block Diagram 24
Front Panel Controls & Indicators 25
Rear Panel Connections and Operation 26
Serial Port Control 27
Serial Interface Commands and Responses 27
Upgrading Firmware 28
Technical Specification RB-SC2 29
5 RB-DAC1 Digital to Analogue Converter 30
Introduction 30
System Block Diagram 30
Front Panel Indicators & Controls 31
Rear Panel Connections and Operation 31
Technical Specifications RB-DAC1 33
6 RB-SP1 Digital Splitter & Combiner 34
Introduction 34
System Block Diagram 34
Front Panel Indicators & Controls 35
Rear Panel Connections and Operation 36
Technical Specifications RB-SP1 38
7 Redbox - Synchronisation Add-On Boards 39
Introduction 39
RB-SYA Analogue Video Sync Board 39
RB-SYD Digital Video Sync Board 39
RB-SYE Sync Board 40
RB-SYW Sync Board 40
8 RB-DS2 Stereo Delay Synchroniser & Time Zone Delay 41
Introduction 41
Extended Mode using Compact Flash™ 42
System Block Diagram 43
Front Panel Controls 43
Rear Panel Connections and Operation 44
The Default Screen 46
The Main Menu 46
Serial Port Control 51
Serial Interface Commands and Responses 51
Upgrading Firmware 53
Technical Specifications RB-DS2 53
Opening the RB-DS2 to Add a Compact Flash Card 54

Contents
9 RB-DS2R Remote Switch Panel For RB-DS2 58
Introduction 58
Technical Specification For RB-DS2R 59
10 RB-PD2 Stereo Profanity Delay 60
Introduction 60
System Block Diagram 61
Quickstart Guide 62
Front Panel Controls 64
Rear Panel Connections 66
The Default Screen 68
The Main Menu 68
Review Mode 74
Serial Port Control 75
Serial Interface Commands and Responses 75
Upgrading Firmware 78
Technical Specification RB-PD2 79
11 RB-DD4 4 Channel Digital Audio Delay 80
Front Panel Controls and Indicators 81
Delay Button Modes 83
Rear Panel Controls & Connectors 84
Rear Panel DIPSwitches 84
RB-DD4 Inputs 86
RB-DD4 Outputs 87
Serial Port Control 87
Serial Interface Commands and Responses 87
SCi for the RB-DD4 91
Status Page 91
Unit Setup Page 92
Miscellaneous Page 93
Updating the Firmware 93
Technical Specification For RB-DD4 94
12 RB-AEC Acoustic Echo Canceller 96
Introduction 96
Category 96
Product Function 96
Typical Applications 96
Features 96
Operation of the RB-AEC 97
Front Panel Controls and Indicators 99
Rear Panel Connections and Controls 99
Inputs 99
Outputs 99
Mains Power 101
Applications 102
How to Remove Delayed Presenter’s Audio From Their
Earpiece 102
The Problem: 102
The Solution: 102
How to Remove Delayed Caller Audio From
The Telephone Line 103
The Problem: 103
The Solution: 103
Calibration 104
Webserver & Unit Discovery 104
Home Page 105
Far End and Near End Input Type 105
Adaption Status 105
Network Page 108
Network Settings 108
Device Info Page 109
Update Page 110
Technical Specification For RB-AEC 111

Figures
Figures
Fig A: RB-RK1Small Redbox Front Rack-mount Kit . v
Fig B: RB-RK2 Small Redbox Rear Rack-mount Kit. vi
Fig C: RB-RK3 Large Redbox Rear Rack-mount Kit. vi
Fig 1-1: RB-ADDA Front Panel 1
Fig 1-2: RB-ADDA System Block Diagram 2
Fig 1-3: RB-ADDA Rear Panel 2
Fig 1-4: RB-ADDA Full Scale dB Settings 4
Fig 1-5: RB-ADDA Status Select Switches 4
Fig 1-6: RB-ADDA Frequency and Sync Rotary Switch 5
Fig 2-1: RB-ADDA2 Front Panel 7
Fig 2-2: RB-ADDA2 System Block Diagram 9
Fig 2-3: SYNC Button & LEDs 9
Fig 2-4: A/D SOURCE Select Button & LEDs 9
Fig 2-5: FREQUENCY Set Button & LEDs 9
Fig 2-6: CS DATA Button & LEDs 10
Fig 2-7: BITS Button & LEDs 10
Fig 2-8: D/A SOURCE Select Button & LEDs 10
Fig 2-9: RB-ADDA2 Rear Panel 10
Fig 3-1: RB-SC1 Front Panel 16
Fig 3-2: RB-SC1 System Block Diagram 16
Fig 3-3: RB-SC1 Rear Panel 17
Fig 3-4: RB-SC1 Status Switches 18
Fig 3-5: RB-SC1 Frequency and Sync Rotary Switch Settings 19
Fig 4-1: RB-SC2 Front Panel 21
Fig 4-2: RB-SC2 X-Lock Sync Mode 22
Fig 4-3: RB-SC2 Optional Video Sync Installation 23
Fig 4-4: RB-SC2 System Block Diagram 24
Fig 4-5: FREQUENCY Set Button & LEDs 25
Fig 4-6: CS DATA Button & LEDs 25
Fig 4-7: INPUT 1 & INPUT2 Source Select Button & LEDs 25
Fig 4-8: SYNC Button & LEDs 25
Fig 4-9: RB-SC2 Rear Panel 26
Fig 4-10: Serial Port Default Settings 27
Fig 4-11: Serial Interface Commands and Responses 28
Fig 5-1: RB-DAC1 Front Panel 30
Fig 5-2: RB-DAC1 System Block Diagram 30
Fig 5-3: RB-DAC1 Front Panel 31
Fig 5-4: RB-DAC1 Rear Panel 31
Fig 5-5: RB-DAC1 Full Scale Digits and De-emphasis
Settings Switches 32
Fig 6-1: RB-SP1 Front Panel 34
Fig 6-2: RB-SP1 System Block Diagram 34
Fig 6-3: RB-SP1 Front Panel 35
Fig 6-4: RB-SP1 Type and Mode Flow Diagrams 36
Fig 6-5: RB-SP1 Rear Panel 36
Fig 6-6: RB-SP1 Mode Select Dip Switches 37
Fig 7-1: RB-SYA Analogue Video Sync Board For RB-SC2
(PAL, NTSC, SECAM) 39
Fig 7-2: RB-SYD Digital Video Sync Board For RB-SC2
(HD-SDI, SD-SDI) 39
Fig 7-3: RB-SYE Sync Board 40
Fig 7-4: RB-SYW Sync Board 40
Fig 8-1: RB-DS2 Front Panel 41
Fig 8-2: RB-DS2 System Block Diagram 43
Fig 8-3: Front Panel CONTROL 43
Fig 8-4: RB-DS2 Rear Panel 44
Fig 8-5: The Default Screen 46
Fig 8-6: The Main Menu 46
Fig 8-7: Maximum Delays in Normal Mode
(Using On-Board Memory Only) 55
Fig 8-8: Maximum Delays in Extended FAT Mode with 1 GB
Compact Flash™ Memory Card Installed 56
Fig 8-9: Maximum Delays in Extended RAW Mode with 16 GB
Compact Flash™ Memory Card Installed. 57
Fig 9-1: RB-DS2R Front Panel 58
Fig 9-2: RB-DS2R Rear Panel 58
Fig 10-1: RB-PD2 Front Panel 60
Fig 10-2: RB-PD2 System Block Diagram 61
Fig 10-3: RB-PD2 Rotary Control Operation 64
Fig 10-4: RB-PD2 Front Panel Buttons 65
Fig 10-5: RB-PD2 Rear Panel 66
Fig 10-6: The Default Screen 68
Fig 10-7: The Main Menu Screen 68
Fig 10-8: The Record Screen 71
Fig 11-1: RB-DD4 Front Panel 80
Fig 11-2: RB-DD4 Block Diagram 81
Fig 11-3: Front Panel Controls and Indicators 81

Figures
Fig 11-4: DELAY Button 82
Fig 11-5: CHANNEL SELECT Button 82
Fig 11-6: INPUTS 1 & 2 Button 82
Fig 11-7: MONITOR SELECT Button 82
Fig 11-8: Headphone Output & Level Controls 83
Fig 11-9: Reset Button 83
Fig 11-10: Minimum delay values (at 0 frames) due to
inherent delay at different input to output
sample rates within the unit, measured in ms 84
Fig 11-11: RB-DD4 Rear Panel DIPSwitch Block 84
Fig 11-12: RB-DD4 Rear Panel 84
Fig 11-13: Serial Port Default Settings 87
Fig 11-14: Status Page 91
Fig 11-15: Unit Setup Page 92
Fig 11-16: Miscellaneous Page 93
Fig 12-1: The RB-AEC Acoustic Echo Canceller 96
Fig 12-2: The RB-AEC Operational Block Diagram 97
Fig 12-3: The RB-AEC Functional Block Diagram 98
Fig 12-4: The RB-AEC Front Panel 99
Fig 12-5: The RB-AEC Rear Panel 100
Fig 12-6: The RB-AEC Sonifex Service Discovery Tool 104
Fig 12-7: The RB-AEC Webserver Interface - Home 105
Fig 12-8: The RB-AEC Webserver Interface - Configuration 106
Fig 12-9: The RB-AEC Webserver Interface - Network 108
Fig 12-10: The RB-AEC Webserver Interface - Device Info 109
Fig 12-11: The RB-AEC Webserver Interface - Update 110

Warranty Registration
Sonifex Limited y 61 Station Road y Irthlingborough y Northamptonshire y NN9 5QE y United Kingdom
Tel: [phone] y Fax: [phone] y Email: t[email protected] y Internet: www.sonifex.co.uk
Register Online for an
Extended 2 Year Warranty
As standard, Sonifex products are
supplied with a 1 year back to base
warranty.
If you register the product online, you
can increase your product warranty
to 2 years and we can also keep
you informed of any product design
improvements or modifications.
To register your product, please go online to www.sonifex.co.uk/register
Product:
Serial No:

ii
Warranty
Product Warranty - 2 Year Extended
As standard, Sonifex products are supplied with a 1 year back to base
warranty. In order to register the date of purchase and so that we can keep
you informed of any product design improvements or modifications, it is
important to complete the warranty registration online. Additionally, if you
register the product on the Sonifex website, you can increase your product
warranty to 2 years. Go to the Sonifex website at: https://www.sonifex.
co.uk/technical/register/index.asp to apply for your 2 year warranty.
Note: For your own records the product serial number is recorded on the
CE certification page of this handbook.
Sonifex Warranty & Liability Terms & Conditions
1. Definitions
‘the Company’ means Sonifex Ltd and where relevant includes companies
within the same group of companies as Sonifex Limited.
‘the Goods’ means the goods or any part thereof supplied by the Company
and where relevant includes: work carried out by the Company on items
supplied by the Purchaser; services supplied by the Company; and software
supplied by the Company.
‘the Purchaser’ means the person or organisation who buys or has agreed
to buy the Goods.
‘the Price’ means the Price of the Goods and any other charges incurred by
the Company in the supply of the Goods.
‘the Warranty Term’ is the length of the product warranty which is usually
12 months from the date of despatch; except when the product has been
registered at the Sonifex website when the Warranty Term is 24 months
from the date of despatch.
‘the Contract’ means the quotation, these Conditions of Sale and any
other document incorporated in a contract between the Company and the
Purchaser.
This is the entire Contract between the parties relating to the subject
matter hereof and may not be changed or terminated except in writing in
accordance with the provisions of this Contract. A reference to the consent,
acknowledgement, authority or agreement of the Company means in
writing and only by a director of the Company.
2. Warranty
a. The Company agrees to repair or (at its discretion) replace Goods
which are found to be defective (fair wear and tear excepted) and
which are returned to the Company within the Warranty Term
provided that each of the following are satisfied:
i. notification of any defect is given to the Company immediately
upon its becoming apparent to the Purchaser;
ii. the Goods have only been operated under normal operating
conditions and have only been subject to normal use (and
in particular the Goods must have been correctly connected
and must not have been subject to high voltage or to ionising
radiation and must not have been used contrary to the
Company’s technical recommendations);
iii. the Goods are returned to the Company’s premises at the
Purchaser’s expense;
iv. any Goods or parts of Goods replaced shall become the
property of the Company;
v. no work whatsoever (other than normal and proper
maintenance) has been carried out to the Goods or any part of
the Goods without the Company’s prior written consent;

iii
Warranty
vi. the defect has not arisen from a design made, furnished or
specified by the Purchaser;
vii. the Goods have been assembled or incorporated into other
goods only in accordance with any instructions issued by the
Company;
viii. the defect has not arisen from a design modified by the
Purchaser;
ix. the defect has not arisen from an item manufactured by a person
other than the Company. In respect of any item manufactured
by a person other than the Company, the Purchaser shall only be
entitled to the benefit of any warranty or guarantee provided by
such manufacturer to the Company.
b. In respect of computer software supplied by the Company the
Company does not warrant that the use of the software will be
uninterrupted or error free.
c. The Company accepts liability:
(i) for death or personal injury to the extent that it results from the
negligence of the Company, its employees (whilst in the course
of their employment) or its agents (in the course of the agency);
(ii) for any breach by the Company of any statutory undertaking as
to title, quiet possession and freedom from encumbrance.
d. Subject to conditions (a) and (c) from the time of despatch of
the Goods from the Company’s premises the Purchaser shall be
responsible for any defect in the Goods or loss, damage, nuisance
or interference whatsoever consequential economic or otherwise or
wastage of material resulting from or caused by or to the Goods. In
particular the Company shall not be liable for any loss of profits or
other economic losses. The Company accordingly excludes all liability
for the same.
e. At the request and expense of the Purchaser the Company will test
the Goods to ascertain performance levels and provide a report of
the results of that test. The report will be accurate at the time of the
test, to the best of the belief and knowledge of the Company, and the
Company accepts no liability in respect of its accuracy beyond that
set out in Condition (a).
f. Subject to Condition (e) no representation, condition, warranty or
other term, express or implied (by statute or otherwise) is given by
the Company that the Goods are of any particular quality or standard
or will enable the Purchaser to attain any particular performance
or result, or will be suitable for any particular purpose or use
under specific conditions or will provide any particular capacity,
notwithstanding that the requirement for such performance, result or
capacity or that such particular purpose or conditions may have been
known (or ought to have been known) to the Company, its employees
or agents.
g. (i) To the extent that the Company is held legally liable to the
Purchaser for any single breach of contract, tort, representation
or other act or default, the Company’s liability for the same
shall not exceed the price of the Goods.
(ii) The restriction of liability in Condition (g)(i) shall not apply to
any liability accepted by the Seller in Condition (c).
h. Where the Goods are sold under a consumer transaction (as defined
by the Consumer Transactions (Restrictions on Statements) Order
1976) the statutory rights of the Purchaser are not affected by these
Conditions of Sale.
Unpacking Your Product
Each product is shipped in protective packaging and should be inspected
for damage before use. If there is any transit damage take pictures of the
product packaging and notify the carrier immediately with all the relevant

iv
CE Conformity
details of the shipment. Packing materials should be kept for inspection and
also for if the product needs to be returned.
The product is shipped with the following equipment so please check to
ensure that you have all of the items below. If anything is missing, please
contact the supplier of your equipment immediately.
Item Quantity
Product unit 1
IEC mains lead fitted with moulded mains plug 1
Handbook and warranty card 1
If you require a different power lead, please let us know when ordering the
product.
Repairs & Returns
Please contact Sonifex or your supplier if you have any problems with your
Sonifex product. Email [e-mail] for the repair/
upgrade/returns procedure, or for support & questions regarding the
product operation.
Conformity
The products in this manual comply with the essential requirements of the
relevant European health, safety and environmental protection legislation.
The technical justification file for this product is available at Sonifex Ltd.
The declaration of conformity can be found at:
https://www.sonifex.co.uk/declarations
Safety & Installation of Mains
Operated Equipment
There are no user serviceable parts inside the equipment. If you should ever
need to look inside the unit, always disconnect the mains supply before
removing the equipment covers. The cover is connected to earth by means of
the fixing screws. It is essential to maintain this earth/ground connection to
ensure a safe operating environment and provide electromagnetic shielding.
Voltage Setting Checks
Ensure that the machine operating voltage is correct for your mains power
supply by checking the box in which your product was supplied. The voltage
is shown on the box label. The available voltage settings are 115V, or 230V.
Please note that all products are either switchable between 115V and 230V,
or have a universal power supply.
Fuse Rating
The product is supplied with a single fuse in the live conducting path of the
mains power input. For reasons of safety it is important that the correct
rating and type of fuse is used. Incorrectly rated fuses could present a
possible fire hazard, under equipment fault conditions. The active fuse is
fitted on the outside rear panel of the unit.
Power Cable & Connection
An IEC power connector is supplied with the product which has a moulded
plug attached.
The mains plug or IEC power connector is used as the disconnect device.
The mains plug and IEC power connector shall remain readily operable to
disconnect the apparatus in case of a fault or emergency.
The mains lead is automatically configured for the country that the product is
being sent to, from one of:

v
Safety & Installation
Territory Voltage IEC Lead Type Image
UK & Middle East 230V UK 3 pin to IEC lead
Europe 230V European Schuko round 2 pin to
IEC lead
USA, Canada and
South America 115V 3 flat pin to IEC lead
Australia & New
Zealand 230V Australasian 3 flat pin to IEC lead
Connect the equipment in accordance with the connection details and
before applying power to the unit, check that the machine has the correct
operating voltage for your mains power supply.
This apparatus is of a class I construction. It must be connected to a mains
socket outlet with a protective earthing connection.
Important note: If there is an earth/ground terminal on the rear panel of
the product then it must be connected to Earth.
WEEE Directive
The Waste Electrical and Electronic Equipment (WEEE)
Directive was agreed on 13 February 2003, along with the
related Directive 2002/95/EC on Restrictions of the use of
certain Hazardous Substances in electrical and electronic
equipment (RoHS). The Waste Electrical and Electronic Equipment Directive
(WEEE) aims to minimise the impacts of electrical and electronic equipment
on the environment during their life times and when they become waste.
All products manufactured by Sonifex Ltd have the WEEE directive label
placed on the case. Sonifex Ltd will be happy to give you information about
local organisations that can reprocess the product when it reaches its “end
of use”, or alternatively all products that have reached “end of use” can be
returned to Sonifex and will be reprocessed correctly free of charge.
Atmosphere/Environment
This apparatus should be installed in an area that is not subject to excessive
temperature variation (<0°C, >50°C), moisture, dust or vibration.
This apparatus shall not be exposed to dripping or splashing, and no objects
filled with water, such as vases shall be placed on the apparatus.
Fitting Redboxes
Redboxes can be fixed to the underside of a desk, or other surfaces
using 4.2mm holes in the sides and fixed with 2 x M4 screws or 2 x No. 6
countersink wood screws.
Fig A: RB-RK1Small Redbox Front Rack-mount Kit .

vi
Safety & Installation
Fig C: RB-RK3 Large Redbox Rear Rack-mount Kit.
Fig B: RB-RK2 Small Redbox Rear Rack-mount Kit.
They can also be rack-mounted, with either the front, or rear of the Redbox positioned at the front of the rack (Note: this product is front rack-mounted as
standard):
Front Mounting Redboxes: For rack mounting smaller (28cm) units the optional RB-RK1 (Red) or RB-RK1B (Black) kit can be used (which include
4 off M6 panel fixing screws).
Rear Mounting a Redbox: For rear panel mounting you can use either the RB-RK2 (in this case), or RB-RK3, depending on the size of your Redbox.

1
Digital Audio Converters - RB- ADDA 1
Fig 1-1: RB-ADDA Front Panel
Using 24 bit, 96kHz capable devices, the RB-ADDA A/D and D/A Converter
is a 1U rack-mount which produces an AES/EBU or S/PDIF level digital audio
output from a balanced XLR or unbalanced phono stereo audio input. The
unit also produces a stereo balanced XLR or unbalanced phono output from
an incoming AES/EBU or S/PDIF digital input signal.
The unit operates in four modes:
Master Mode - In this mode the unit receives an analogue
audio signal, which is digitised and formatted for digital serial
transmission (IEC958). The necessary clock signals
are generated internally from an on board master clock at a selectable rate
(32kHz, 44.1kHz, 48kHz, 64kHz, 88.1kHz or 96kHz).
Slave Mode - In this mode the unit automatically detects the presence of a
digital audio sync signal, if present at the digital input, and synchronises the
digital output to it. If no sync is present, no output will be generated.
Auto Mode - Here the unit synchronises to the digital audio sync signal
if present at the digital input and uses the internal master clock only if no
sync input signal is detected. In this case, the internal master clock is used
at the selected sample rate.
Auto Lock Mode - This operates like the auto mode. The difference is that
if the sync input signal is lost, the unit will revert to an internal master clock
rate as near as possible to the last sync signal received.
When operating in sync modes, the front panel power LED flashes
whenever the unit is not synchronised to the incoming digital signal, or
when the unit is being calibrated. The RB-ADDA should be calibrated once it
has been powered up for more than 10 minutes.
The analogue inputs have left and right level controls using pre-set
potentiometers and DIP switches allowing a signal range from +9dBu to
+27dBu. The analogue outputs have an output level control, allowing
full-scale settings selectable from +12dBu, +18dBu or +24dBu. There are
factory-set internal level controls for the analogue outputs allowing gain
adjustment of ±1dB.
There are buttons to select either the AES/EBU or S/PDIF input or output
for the D/A and A/D sections respectively. The output bit depth can be
selected from 16, 20 or 24 bits. Inputs of a different bit depth to the output
are dithered using a psychoacoustic noise filter.
For the digital output, there is a switch available to define the content of
the channel status bits embedded within the digital audio stream. The
channel status bits can be set to either Professional or Consumer Mode.
1 RB-ADDA Combined A/D and D/A Converter
Introduction

2
1 Digital Audio Converters - RB- ADDA
System Block Diagram
Fig 1-2: RB-ADDA System Block Diagram
Front Panel Indicators
The LED on the front panel is normally red to indicate that power is present
on the unit. However, it also has a secondary role to indicate the status of
the digital inputs
Fast flashing between red and amber – indicates a loss of digital input signal
or that the unit is being calibrated.
Rear Panel Connections and Operation
RB-ADDA Inputs
XLR Analogue Inputs (Left and Right)
The XLR 3 pin sockets used for the left and right channel inputs are
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bridging. Each XLR has the following connections:
XLR Analogue Inputs XLR Analogue Outputs AES/EBU Output Status Select Switches
AES/EBU
Input
RCA Phono
Inputs
RCA Phono
Outputs
S/PDIF
Input & Output
Frequency & Synch
Mode Rotary Switch
Digital Select Button Digital Select Button
Fig 1-3: RB-ADDA Rear Panel

3
Digital Audio Converters - RB- ADDA 1
Pin 1: Screen.
Pin 2: Phase.
Pin 3: Non-phase.
RCA Phono Inputs (Left and Right)
The two left and right RCA inputs are unbalanced and have an impedance of
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Input Level Adjustment
The input gain can be individually adjusted for left and right channels by
dipswitches and through pre-set potentiometers accessible on the rear
panel. For full scale dB settings refer to Fig 1-4.
Individual preset pots give a further ± 3dBu to give a total gain range of
+9dBu to +27dBu for full-scale digits. The consumer input on the phono
connector has a further 10dbU gain incorporated to give a total gain range
of -1dBu to +17dBu for full-scale digits.
AES/EBU Inputs
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following connections:
Pin 1: Screen
Pin 2: Phase
Pin 3: Non-phase
The signals on this connector should meet the IEC 60968 specification
S/PDIF Inputs
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RB-ADDA Outputs
Analogue Outputs (Left and Right)
The XLR 3 pin output plug connectors are electronically balanced with an
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Pin 1: Screen.
Pin 2: Phase.
Pin 3: Non-phase.
RCA Phono Outputs (Left and Right)
These RCA (phono) outputs are unbalanced and have an output impedance
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Output Level Adjustment
The output gain can be individually adjusted for left and right channels
through the rear panel by dipswitches. Each output gain can be set for a
signal of full-scale digits in the digital domain to give +12, +18 or +24dBu
output on the XLR connectors (see Fig 1-4). The consumer output on the
phono connector has a further 10dbU attenuation incorporated.
AES/EBU Output
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following connections:
Pin 1: Screen
Pin 2: Phase
Pin 3: Non-phase
The signals on this connector will comply with the IEC 60968 specification
S/PDIF Output
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Rear Panel Controls
Full Scale dB Settings
The full-scale dB settings can be set for signals of +12, +18, +24 dBu to give
full-scale digits in the digital domain.
Analogue (A/D) Input
Full Scale Setting
(dBu)
Switch 1 Switch 2
+12 OFF OFF
+18 ON OFF
+24 ON ON

4
1 Digital Audio Converters - RB- ADDA
Analogue (D/A)
Output Full Scale
Setting (dBu)
Switch 3 Switch 4
+12 OFF OFF
+18 ON OFF
+24 ON ON
Fig 1-4: RB-ADDA Full Scale dB Settings
Status Select Switches
These switches are used to determine the status or content of the digital
signals. The type of information encoded in the channel status bits of a
digital audio signal can be professional or consumer and is determined by
switch 1.
If de-emphasis is selected (switch 2) the RB-ADDA will decode 50/15μs
emphasis when indicated by certain channel status bits in the incoming
digital audio data.
The sample size for the analog to digital conversion can be set to 24, 20 or
16 bits (switch 3 & 4). When the signal is truncated from 24 bits, a psycho-
acoustic filter is applied to maintain optimum signal quality. These settings
are summarised by the table in Fig 1-5, which is also shown on the top
panel of the unit.
Status Bits
1 ON Professional 16 20 24
1 OFF Consumer 3 OFF OFF ON
2 ON De-emphasis On 4 OFF ON ON
2 OFF De-emphasis Off
Fig 1-5: RB-ADDA Status Select Switches
Digital Select Buttons
These buttons are used to switch the digital connection between the AES/
EBU XLR connector (button out) and the S/PDIF phono connector (button
in) for the digital input and the digital output.
Analogue Select Button
This button is used to switch the Analogue input between the balanced XLR
connector (button out) and the unbalanced phono connector (button in).
Frequency and Sync Mode Rotary Switch
This rotary switch is used to select the Synchronisation Mode and to
select the frequency of the digital output when using the on-board clock
generator. There are 4 modes of operation: - Master Mode, Auto Sync
Mode, Auto Lock Sync Mode & Slave Mode.
In Master Sync Mode, switch positions 0 – 5, the digital output sample rate
is simply set by, and locked to, the internal on-board clock generator. No
sync signal is used or required.
In Auto Sync Mode, switch positions 6– B, the digital output sample rate
follows the digital input. When the digital input signal is not present the
output sample rate will be set by, and locked to, the internal on-board clock
generator at a frequency determined by the switch position.
In Auto-Lock Sync Mode, switch position C, No output will be generated
until lock is achieved with a digital input signal. The digital output sample
rate now follows the digital input. If the digital input signal is removed then
the output sample rate will be set by, and locked to, the internal on-board
clock generator at the closest frequency available to the previous digital
input.
In Slave Sync Mode, switch position D, the digital output sample rate
follows the digital input. When the digital input signal is not present the
digital output is turned off.

5
Digital Audio Converters - RB- ADDA 1
The following table, also printed on the top of the unit, summarises the
above settings and shows the sample rate generated by the internal clock
generator in master and auto sync modes.
Frequencies and Sync Modes
Rotary Switch
Number
Mode Sample Frequency
(kHz)
0 Master 32
1 Master 44.1
2 Master 48
3 Master 64
4 Master 88.2
5 Master 96
6Auto32
7 Auto 44.1
8Auto48
9Auto64
A Auto 88.2
BAuto96
C Auto Lock -
D Slave -
Fig 1-6: RB-ADDA Frequency and Sync Rotary Switch
Test/Calibration Mode
For optimum performance of the RB-ADDA, the unit should be calibrated
when it has been powered up for approximately 10-15 minutes. The
circuitry and chipsets contained in the unit will warm up during this time
and the performance will deteriorate unless calibrated (the noise floor
and dynamic range will be 1-2dB down on their best). The calibration cycle
calibrates the gain and the zero reference of the A/D converter.
To calibrate the RB-ADDA, set the rotary FREQUENCIES AND SYNC MODES
switch to position “F”. The power LED on the front panel will flash quickly
for 2 – 3 seconds and will illuminate fully when the unit is calibrated. Once
calibration is complete, reset the rotary switch to the position that you
require.

6
1 Digital Audio Converters - RB- ADDA
Technical Specifications RB-ADDA
A/D Connections
Analogue Inputs: 2 x XLR 3 pin (balanced) (L & R)
2 x RCA phono (unbalanced) (L & R)
Digital Outputs: 1 x AES/EBU XLR 3 pin plug
1 x S/PDIF RCA phono socket
A/D Audio Specification
Maximum Input Level: +27dBu (balanced inputs)
Maximum Input Level: +17dBu (unbalanced inputs)
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Input Levels: Switchable +24dBu/+18dBu/+12dBu for FSD
Gain Range: Adjustable 3dB loss to 3dB gain (L and R adjust)
Signal to Noise: Better than –109dbFS (RMS A-weighted
at 24bit)
Dynamic Range: >110dB
Distortion and Noise: >96dB THD + N at 1kHz
D/A Connections
Digital Inputs: 1 x AES/EBU XLR 3 pin female
1 x S/PDIF RCA phono
Analogue Outputs: 2 x XLR 3 pin male (balanced) (L & R)
2 x RCA phono (unbalanced) (L & R)
D/A Audio Specification
Max Output Level: +24dBu (balanced outputs)
Max Output Level: +14dBu (unbalanced outputs)
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Dynamic Range: >100dB
Gain Range: Selectable 12dBu, 18dBu or 24dBu output
level, ref FSD
Other Connections
Mains Input: Filtered IEC, 110-120V, or 220-240V switchable,
10W max
Fuse Rating: Anti-surge fuse 100mA 20 x 5mm (230VAC)
Anti-surge fuse 250mA 20 x 5mm (115VAC)
Operational Controls
Analogue Input Select: XLR or phono, via push-switch
Bit Depth: 16, 20 or 24 bits via DIP switch
Digital Output Select: AES/EBU or S/PDIF, via push-switch
Modes & Frequencies: 16 way rotary DIP switch
Digital Input Select: AES/EBU or S/PDIF, via push-switch
Channel Status Bits: Set to consumer or professional mode via
DIP switch
Equipment Type
RB-ADDA Combined A/D and D/A converter
Physical Specifications
Dimensions (Raw) 48cm (W) x 10.8cm (D) x 4.2cm (H) (1U)
19” (W) x 4.3” (D) x 1.7” (H) (1U)
Dimensions (Boxed) 58.5cm (W) x 22.5cm (D) x 7cm (H)
23” (W) x 8.9” (D) x 2.8” (H)
Weight Nett: 1.6kg Gross: 2.2kg
Nett: 3.5lbs Gross: 4.8lbs

7
Digital Audio Converters - RB-ADDA2 2
2 RB-ADDA2 Combined A/D and D/A Converter 24bit 192kHz
Introduction
Fig 2-1: RB-ADDA2 Front Panel
The RB-ADDA2 A/D and D/A converter is a 1U rack-
mount which produces an AES/EBU, S/PDIF or TOSlink
optical level digital audio output from a balanced XLR or
unbalanced phono stereo audio input. It also produces a
stereo balanced XLR or unbalanced phono output from an
incoming AES/EBU, S/PDIF or TOSlink optical digital input
signal.
The RB-ADDA2 is a high performance, enhanced version of the RB-ADDA
providing the following additional features:
• It supports higher sample frequency rates up to and including 176.4kHz
and 192kHz.
• It has additional independent AES/EBU and Word Clock synchronising
inputs, so that the A/D and D/A sections can operate independently, with
the digital outputs synchronised to an external master reference clock.
• It has TOSlink optical digital audio input and output.
• It has front panel push-button switches for all the main settings. The
buttons are arranged in sets, where pressing the button advances the
current selection and LED indicator.
Sync Button
and LEDs
Frequency Set
Button and LEDs
Bits Button
and LEDs
A/D Source Select
Button and LEDs
CS Data Button
and LEDs
D/A Source Select
Button and LEDs
Reset
Button
• A serial RS232 port is included so that the RB-ADDA2 settings can be
controlled remotely. The front panel LED indicators alter automatically
when using RS232 commands.
The A/D SOURCE push-button is used to select from either the balanced
or unbalanced stereo analogue inputs and this push-button also defines
the input level for full scale digits at one of +12dBFS, +18dBFS or
+24dBFS. These values can then be fine-tuned by using rear-panel pre-set
potentiometers which give another ±3dB of gain adjustment, allowing a
signal range from +9dBu to +27dBu. The RCA phono inputs have a further
10dB nominal gain incorporated to give a total signal range of -1dBu to
+17dBu for full-scale digits.
For the digital output, there are three push-button switches to select the
sample frequency, bit depth and status bit modes. The FREQUENCY button
allows selection of the master sample frequency from one of 32kHz,
44.1kHz, 48kHz, 88.2kHz, 96kHz, 176.4kHz or 192kHz. The BITS button sets
the output bit depth as one of 16, 20 or 24 bits, and the CS DATA button
defines the content of the channel status bits embedded within the digital
2
9
1

8
2 Digital Audio Converters - RB-ADDA2
audio stream. The channel status can be forced to either Professional
Mode (PRO), Consumer Mode (CON) or to follow the mode of the input
(FOLLOW).
The SYNC button is used to select the synchronisation input, from Word
Clock, AES/EBU or the D/A input, and also the synchronisation mode of the
digital output. The A/D section of the RB-ADDA2 operates in four selectable
modes:
Master Mode
In this mode the unit receives an analogue audio signal, which is digitised
and formatted for digital serial transmission (IEC958). The necessary
clock signals are generated internally from an on board master clock at
a selectable rate (32kHz, 44.1kHz, 48kHz, 88.2kHz, 96kHz, 176.4kHz or
192kHz).
Slave Mode
In this mode the unit is synchronised to an external source, using the digital
audio sync or D/A input signal from which the clock signals are stripped,
or to the TTL level Word Clock. The FREQUENCY LED will indicate the
synchronised sample frequency and if no sync is present, no output will be
generated.
Auto Mode
Here, the unit is synchronised to an external source, using the digital audio
sync or D/A input signal from which the clock signals are stripped, or to
the TTL level Word Clock. If no sync signal is present the unit runs from the
onboard master clock at a rate selected by the front panel control (32kHz,
44.1kHz, 48kHz, 88.2kHz, 96kHz, 176.4kHz or 192kHz).
Auto Lock Mode
This operates like the auto mode except that if no sync signal is present
the unit will run at the closest master clock rate to the last locked incoming
signal. The FREQUENCY LED will indicate the synchronised sample
frequency.
When operating in sync modes, the SYNC button flashes whenever the unit
is not synchronised to the incoming digital signal.
The D/A section has one SOURCE push-button which is used to select the
digital input source from AES/EBU, S/PDIF or TOSlink optical and which
also sets the analogue output level to be generated for full scale digits,
from either +12dBFS, +18dBFS or +24dBFS. The RCA phono outputs have a
further 10dB nominal attenuation to reduce the signal to that expected by
consumer equipment. There are factory-set internal level controls for fine
tuning the analogue output gain adjustment. If no digital audio source is
present, the D/A SOURCE button flashes.
The RB-ADDA2 automatically decodes 50/15μs emphasis if this is indicated
by certain channel status bits in the incoming digital audio data. In both A/D
and D/A sections, audio is sent to all of the outputs simultaneously. A red
LED indicates when power to the RB-ADDA2 is on.