Red Box Handbook
Redbox
User Handbook No 2
Matching Converters, Distribution
Amplifiers & Headphone Amplifiers
RB-UL1
Single stereo unbalanced to balanced converter
RB-UL2
Dual stereo unbalanced to balanced converter
RB-UL4
Quad stereo unbalanced to balanced converter
RB-LU4
Quad stereo balanced to unbalanced converter
RB-BL2
Single stereo bi-directional matching converter
RB-BL4
Dual stereo bi-directional matching converter
RB-PA2
Dual stereo RIAA phono amplifier
RB-LI2
Stereo line isolation unit
RB-PLI6
6 way mono passive line isolation unit
RB-DA6 6 way stereo distribution amplifier
RB-DA6G
6 way stereo distribution amplifier with output
gain control
RB-DA4x5
4 input, 4 x 5 output distribution amplifier/mixer
RB-DDA6A
6 way stereo AES/EBU digital distribution amplifier
RB-DDA6S
6 way stereo S/PDIF digital distribution amplifier
RB-DDA6W
6 way word clock digital distribution amplifier
RB-HD1
Stereo headphone amplifier
RB-HD2
Dual stereo headphone amplifier
RB-HD6
6 way stereo headphone distribution amplifier
RB-DHD6
Digital 6 way stereo headphone distribution amplifier
Revision 2.02 June, 2007
©Sonifex Ltd, 2000-7
All Rights Reserved
Sonifex Ltd, 61, Station Road, Irthlingborough,
Northants, NN9 5QE, England.
Tel : +44 (0)1933 650 700
Fax : +44 (0)1933 650 726
Email : [email protected] or [email protected]
Web : http://www.sonifex.co.uk
Information in this document is subject to change without notice and does not represent
a commitment on the part of Sonifex Ltd. Sonifex Ltd shall not be liable for any loss or
damage whatsoever arising form 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, or 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 products.
b
Redbox User Handbook No 2
CONTENTS
Warranty i
i
ii
iii
Safety Information
iii
Safety of Mains Operated Equipment
Voltage Setting Checks
Fuse Rating
Power Cable and Connection
Ordering the Correct Mains Lead
iii
iii
iii
iv
iv
Installation Information
iv
Atmosphere
Electromagnetic Radiation
Fitting Redboxes
WEEE & RoHS Directives - Sonifex Statement
iv
iv
iv
vi
MATCHING CONVERTERS
1 RB-UL1 Single, RB-UL2 Dual & RB-UL4 Quad Stereo Unbalanced
To Balanced Converters 1
Introduction System Block Diagram
Rear Panel Connections and Operation
RCA Phono Inputs (Left and Right)
Outputs (Left and Right)
Output Level Adjustment
Technical Specifications
1
1
2
3
3
3
4
2 RB-LU4 Quad Stereo Balanced To Unbalanced Converter 5
Introduction
System Block Diagram
Rear Panel Connections and Operation
Inputs 1-4 (Left and Right) RCA Phono Outputs 1-4 (Left and Right)
Output Level Adjustment
Technical Specifications
5
6
7
7
7
7
8
3 RB-BL2 Single & RB-BL4 Dual Bi-Directional Matching Converter
9
Introduction
System Block Diagram
Rear Panel Connections and Operation
Balanced to Unbalanced Connections
Inputs 1 (& 3) (Left & Right) Output Level Adjustment Unbalanced to Balanced Connections
RCA Phono Inputs 2 (& 4) (Left & Right) Technical Specifications
9
10
10
11
11
11
11
11
12
4 RB-PA2 Dual Stereo RIAA Phono Amplifier 13
Introduction System Block Diagram
Rear Panel Connections and Operation
13
13
14
Redbox User Handbook No 2
CON T E N TS
Warranty and Liability - important the purchaser is advised to read this clause
Unpacking the Redbox
Returning the Warranty Card
c
CON T E N TS
CO N T E N TS
RCA Phono Inputs (Left and Right) Outputs (Left and Right) Output Level Adjustment Pick-up Grounding Post
Technical Specifications
14
14
14
14
15
5 RB-LI2 Stereo Line Isolation Unit
16
Introduction
System Block Diagram
Rear Panel Connections and Operation
Inputs
Isolated Outputs
Loop Outputs
Output Level Adjustment
Internal Jumpers
Technical Specifications
16
16
17
17
17
17
17
18
18
6 RB-PLI6 6 Way Mono Passive Line Isolation Unit
19
Introduction
System Block Diagram
Rear Panel Connections and Operation
Inputs
Outputs
Ground-link Internal Jumpers
Technical Specifications
19
19
20
20
20
20
21
AUDIO DISTRIBUTION AMPLIFIERS
7 RB-DA6 & RB-DA6G 6 Way Stereo Distribution Amplifier
22
Introduction
System Block Diagram
Connections and Operation
Stereo Outputs 1-6 (Mono Outputs 1-12) Input Gain Control (RB-DA6)
Output Gain Control (RB-DA6G)
Stereo/Mono Operation
Technical Specifications
22
23
24
24
24
24
25
25
8 RB-DA4x5 4 Input 4 x 5 Output Distribution Amplifier/Mixer
26
Introduction
System Block Diagram
Rear Panel Connections and Operation
Audio Inputs 1-4
D-Type Audio Output Groups 1-4 Monitor LEDs Input Level Adjustment
Output Level Adjustment
Routing Selection
Alignment Test Tone
Technical Specifications
26
27
27
27
28
28
28
28
28
29
29
9 RB-DDA6A 6 Way Stereo AES/EBU Digital Distribution Amplifier and
RB-DDA6S 6 Way Stereo S/PDIF Digital Distribution Amplifier
30
Introduction
System Block Diagrams
d
30
31-32
Redbox User Handbook No 2
CON TEN TS
33
33
33
33
33
34
10 RB-DDA6W 6 Way Word Clock Distribution Amplifier
35
Introduction
System Block Diagram
Rear Panel Connections and Operations
Word Clock Input
Word Clock Outputs
Technical Specifications
35
36
37
37
37
37
HEADPHONE DISTRIBUTION AMPLIFIERS
11 RB-HD1 Stereo Headphone Amplifier & RB-HD2 Dual
Headphone Amplifier
38
Introduction System Block Diagrams
Front Panel Connections and Controls Stereo Outputs 1-2 (Mono Outputs1-2)
Volume Level Control Stereo Outputs 1-2 (Mono Outputs 1-2)
Channel Volume Controls
Rear Panel Connections and Operation
Main Stereo Inputs (Left and Right) Stereo Input Gain Adjustment (RB-HD1)
Stereo/Mono Operation
Mono Mix Input (RB-HD1)
Mono Mix Input Gain Adjustment (RB-HD1)
Local/Remote Control Operation (RB-HD1)
Remote Connector (RB-HD1)
Technical Specifications 38
39
40
40
40
40
40
41
41
41
42
42
42
42
42
43
12 RB-HD6 6 Way Headphone Distribution Amplifier
44
Introduction System Block Diagram
Rear Panel Connections and Operation
Stereo Input (Left and Right) Stereo/Mono Operation
Channel Insertion Inputs/Parallel Outputs Removing the Equipment Covers
Configuring Insert Inputs/Parallel Outputs
Front Panel Connections and Controls Stereo Outputs 1-6 (Mono Outputs 1-6)
Master Level Control Channel Volume Controls
Technical Specifications 44
45
46
46
46
46
46
47
47
47
48
48
48
13 RB-DHD6 Digital 6 Way Headphone Distribution Amplifier
49
Introduction
System Block Diagram
49
49
Redbox User Handbook No 2
CON T E N TS
Rear Panel Connections and Operations
AES/EBU Input
AES/EBU Outputs
S/PDIF Input
S/PDIF Outputs
Technical Specifications
e
CON T E N TS
CO N T E N TS
f
Front Panel Indicators & Controls
Introduction
Sync & Power Indicator
Headphone Outputs
Volume Control
Rear Panel Connections and Operation
AES/EBU Input
S/PDIF Input
Status Select Switches
Digital Input Select Button
Technical Specifications
49
49
50
50
50
50
50
50
50
51
51
14 Connectors & Cabling
52
XLR 3 Pin Connectors
RCA Phono Connectors
D-Type Connectors
52
52
53
15 Glossary
54
Redbox User Handbook No 2
FIGURES
Figures
Fig A: Packing List.
ii
Fig B: Mains Cable Wire Colours
iv
Fig C: Mains Lead Table.
iv
Fig D: RB-RK1Small Redbox Front Rack-mount Kit .
v
Fig E: RB-RK2 Small Redbox Rear Rack-mount Kit.
v
v
Fig 1-1: RB-UL1 & RB-UL2 Front Panel.
1
Fig 1-2: RB-UL4 Front Panel.
1
Fig 1-3: Block Diagram For a Single Channel (x2 for RB-UL2, x4 for RB-UL4).
1
Fig 1-4: RB-UL1 Rear Panel.
2
Fig 1-5: RB-UL2 Rear Panel.
2
Fig 1-6: RB-UL4 Rear Panel.
2
Fig 2-1: RB-LU4 Front Panel.
5
Fig 2-2: RB-LU4 Block Diagram.
6
Fig 2-3: RB-LU4 Rear Panel.
7
Fig 3-1: RB-BL2 Front Panel.
9
Fig 3-2: RB-BL4 Front Panel.
9
Fig 3-3: RB-BL2/BL4 Block Diagram Single Stereo Channel.
10
Fig 3-4: RB-BL2 Rear Panel.
10
Fig 3-5: RB-BL4 Rear Panel.
11
Fig 4-1: RB-PA2 Front Panel.
13
Fig 4-2: RB-PA2 Block Diagram For a Single Stereo Channel.
13
Fig 4-3: RB-PA2 Rear Panel.
14
Fig 5-1: RB-LI2 Front Panel. 16
Fig 5-2: RB-LI2 System Block Diagram.
16
Fig 5-3: RB-LI2 Rear Panel. 17
Fig 6-1: RB-PLI6 Front Panel.
19
Fig 6-2: RB-PLI6 System Block Diagram.
19
Fig 6-3: RB-PLI6 Rear Panel.
20
Fig 6-4: RB-PLI6 Ground-link Jumper Settings.
20
Fig 7-1: RB-DA6 Front Panel.
22
Fig 7-2: RB-DA6G Front Panel.
22
Fig 7-3: RB-DA6 Block Diagram.
23
Fig 7-4: RB-DA6G Block Diagram.
23
Fig 7-5: RB-DA6 & RB-DA6G Rear Panel.
24
Fig 7-6: RB-DA6 Front Panel.
24
Fig 7-7: RB-DA6G Front Panel.
25
Fig 8-1: RB-DA4x5 Front Panel.
26
Fig 8-2: RB-DA4x5 Block Diagram.
27
Fig 8-3: RB-DA4x5 Rear Panel.
27
Fig 8-4: RB-DA4x5 Audio Output Group15-Way D-Type Plug.
28
Redbox User Handbook No 2
FI G U RE S
Fig F: RB-RK3 Large Redbox Rear Rack-mount Kit.
g
FI G U RE S
FIGURES
h
Fig 8-5: RB-DA4x5 Pinout for Audio Output Group Connector.
28
Fig 8-6: RB-DA4x5 Routing Selection Switch.
28
Fig 8-7: RB-DA4x5 Routing Selection Switch Functions.
29
Fig 9-1: RB-DDA6A/S Front Panel.
30
Fig 9-2: RB-DDA6A System Block Diagram.
31
Fig 9-3: RB-DDA6S System Block Diagram.
32
Fig 9-4: RB-DDA6A Rear Panel.
33
Fig 9-5: RB-DDA6S Rear Panel.
33
Fig 10-1: RB-DDA6W Front Panel.
35
Fig 10-2: RB-DDA6W System Block Diagram.
36
Fig 10-3: RB-DDA6W Rear Panel.
37
Fig 11-1: RB-HD1 Front Panel.
38
Fig 11-2: RB-HD2 Front Panel.
38
Fig 11-3: RB-HD1 Block Diagram.
39
Fig 11-4: RB-HD2 Block Diagram.
39
Fig 11-5: RB-HD1 Front Panel Controls.
40
Fig 11-6: RB-HD2 Front Panel Controls.
40
Fig 11-7: RB-HD1 Rear Panel.
41
Fig 11-8: RB-HD2 Rear Panel.
41
Fig 11-9: RB-HD1 Remote Connector
42
Fig 12-1: RB-HD6 Front Panel.
44
Fig 12-2: RB-HD6 Block Diagram.
45
Fig 12-3: RB-HD6 Rear Panel.
46
Fig 12-4: RB-HD6 Jumper Assignments.
47
Fig 12-5: RB-HD6 Jumper Positions.
47
Fig 12-6: RB-HD6 Front Panel Controls.
47
Fig 12-7: RB-HD6 Master Level Control.
48
Fig 13-1: RB-DHD6 Front Panel.
49
Fig 13-2: RB-DHD6 System Block Diagram.
49
Fig 13-3: RB-DHD6 Front Panel Controls.
49
Fig 13-4: RB-DHD6 Rear Panel.
50
Fig 13-5: RB-DHD6 Status Select Switches.
50
Fig 14-1: XLR Connectors.
52
Fig 14-2: RCA Phono Connector.
52
Fig 14-3: ¼” Jack Connector.
52
Fig 14-4: 25 Way D-Type Connectors.
53
Fig 14-5: 15 Way D-Type Connectors.
53
Fig 14-6: 9 Way D-Type Connectors.
53
Redbox User Handbook No 2
WARR ANT Y
Warranty
Warranty and Liability - important the purchaser is advised to read this clause
(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 12 months of the date of despatch provided that each of the following
are satisfied:
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;
WA RR A N T Y
(i) (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;
(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);
Redbox User Handbook No 2
i
WA R R A N T Y
(ii) For any breach by the Company of any statutory undertaking as to title, quiet
possession and freedom from encumbrance.
WA RR A N T Y
(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 the Redbox
The Redbox is shipped with the following equipment. Please check your packaging to
ensure that you have all of the items below. If anything is missing, please contact the
supplier of your equipment immediately.
Item
Redbox audio interface
IEC Mains lead fitted with moulded mains plug
Handbook and warranty card
Quantity
1
1
1
Fig A: Packing List.
ii
Redbox User Handbook No 2
SAFE T Y & INSTALL ATION
IN FORMATION
Each Redbox is shipped in protective packaging and should be inspected for damage before
use. Where an item is found to have transit damage, notify the carrier immediately with all
the relevant details of the shipment. Packing materials should be kept for inspection and
also for if the product needs to be returned.
Returning the Warranty Card
In order to register the date of purchase so that we can keep you informed of any design
improvements or modifications, it is important to complete the warranty registration
document that is enclosed and return it to Sonifex Ltd in the UK, or register online at
www.sonifex.co.uk/register
Serial Number
………………………………………
Safety Information
Safety of Mains Operated Equipment
This equipment has been designed to meet the safety regulations currently advised
in the country of purchase and it conforms to the safety regulations specified by
use of the CE Mark.
Warning : 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.
Voltage Setting Checks
Ensure that the machine operating voltage is correct for your mains power supply by
checking the rear panel of your Redbox. The available voltage settings are 115V, or 230V.
Please note that all Redboxes are either switchable between 115V and 230V, or have a
universal power supply.
Fuse Rating
S A FE T Y & I N STALL ATION INFO RM ATION
For your own records you should write down the serial number (which can be found on the
rear of the Redbox.
The Redboxes are supplied with a single fuse in the live conducting path of the power
infeed at the power supply. 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. See the Technical Specifications of each product for the fuse
rating. The active fuse is fitted on the outside rear panel of the unit.
Redbox User Handbook No 2
iii
S A F E T Y & I NSTALL ATION
INF O R M AT I ON
Power Cable and Connection
SAFE T Y & IN STALL ATION IN FORMAT I ON
An IEC power connector is supplied with the Redbox, which has a moulded plug, attached
– this is a legal requirement. If no moulded plug has been supplied with your Redbox, please
contact your supplier, because an IEC connector is always supplied from the Sonifex factory.
If for any reason, you need to use the Redbox with a different power cable, you should use
the following wiring guidelines:
Wire Colour
Green, or green and yellow
Blue, or Black
Brown, or Red
Connection
Earth (E)
Neutral (N)
Live (L)
Fig B: Mains Cable Wire Colours
Ordering the Correct Mains Lead
When ordering a Redbox from Sonifex, it is helpful if you can specify your required
operating voltage and mains lead. After the product code add:
UK, for 230V, UK 3 pin to IEC lead
EC, for 230V, European Schuko 2 pin to IEC lead
US, for 115V, 3 pin to IEC lead
AU for 230V, Australasian 3 pin to IEC lead
Fig C: Mains Lead Table.
E.g. order RB-BL2 UK for a UK IEC lead to be supplied.
Installation Information
Atmosphere
The units should be installed in an area that is not subject to excessive temperature
variation (<0°C, >50°C), moisture, dust or vibration.
Electromagnetic Radiation
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.
Fitting Redboxes
Redboxes can be fixed to the underside of a mixing 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.
iv
Redbox User Handbook No 2
SAFE T Y & INSTALL ATION
IN FORMATION
They can also be rack-mounted, with either the front, or rear of the Redbox positioned at the
front of the rack:
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).
Fig D: RB-RK1Small Redbox Front Rack-mount Kit .
Rear Mounting Redboxes: For rear panel mounting you can use either the RB-RK2, or
RB-RK3, depending on the size of your Redbox.
RB-RK2 1U rear panel rack kit for small Redbox range, e.g., RB-BL2
Fig E: RB-RK2 Small Redbox Rear Rack-mount Kit.
e.g. for fitting an RB-BL2:
Wherever you see this symbol an RB-RK2 small Redbox rear panel 19” rack kit can be used :
RB-RK3 1U rear panel rack kit for large Redbox range, e.g., RB-DA6
Fig F: RB-RK3 Large Redbox Rear Rack-mount Kit.
S A FE T Y & I N STALL ATION INFO RM ATION
Wherever you see this symbol an RB-RK1 front panel rack kit can be used :
e.g. for fitting an RB-DA6:
Wherever you see this symbol an RB-RK3 large Redbox rear panel 19” rack kit can be used :
Note: When fitting the rear-mounting rack-kits, a notch has been
left on the inside of the right-hand rack-piece for the mains cable to
pass through. Make sure that the mains cable has been put through
the notch before attaching the right hand rack-piece.
Redbox User Handbook No 2
v
S A F E T Y & I NSTALL ATION
INF O R M AT I ON
WEEE & RoHS Directives - Sonifex Statement
SAFE T Y & IN STALL ATION IN FORMAT I ON
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. It applies to a huge spectrum of products. It encourages
and sets criteria for the collection, treatment, recycling and recovery of waste electrical and
electronic equipment. All products manufactured by Sonifex Ltd have the WEEE directive
label placed on the case. It gives a contact for individuals who are unsure about the correct
procedure when the product has reached its “end of use”.
Sonifex Ltd will be happy to give you information about local organisations that can
reprocess the products, or alternatively all products that have reached “end of use” can be
returned to Sonifex and will be reprocessed correctly free of charge.
Sonifex Ltd has phased out the use of certain hazardous substances identified in the
European Union’s Restriction of Hazardous Substances (RoHS) directive. The RoHS directive
limits the use of certain hazardous substances currently used in EEE manufacture, including
lead, mercury, cadmium, hexavalent chromium, and halide-containing compounds PBB
(polybrominated biphenyl) and PBDE (polybrominated diphenyl ether). Elimination of these
substances will result in more environmentally friendly recycling of electronic equipment.
For the products which Sonifex manufacture, the main area where products were affected
was in the use of lead for manufacturing and assembling electronics circuit boards.
Sonifex Ltd practices lead-free (LF) manufacturing processes. LF solder is used on the
surface-mount PCB manufacturing processes and for hand soldering. The printed circuit
boards (PCBs) used are either gold plated, or immersion tin plated, both of which use no
lead. Historically the PCBs were hot air solder levelled (HASL) PCBs which used tin/lead
based solder.
The manufacturing processes include the assembly of purchased components from various
sources. Product is offered as RoHS compliant, or LF, only after sufficient evidence is received
from the component manufacturers that their components are RoHS compliant. Sonifex
Ltd relies solely on the distributor, or manufacturer, of the components for identification of
RoHS compliance. Thus whilst every effort is made to ensure compliance, Sonifex Ltd makes
no warranty, or certification, or declaration of compliance concerning said components.
Sonifex Ltd defines “Lead Free” as pertaining to any product, which has been manufactured
by Sonifex Ltd using components which have been declared by the manufacturers as
“Lead Free”. All statements by Sonifex Ltd of RoHS compliance are based on component
manufacturer documentation.
vi
Redbox User Handbook No 2
M ATC HIN G CONVERTERS
1
1 RB-UL1 Single, RB-UL2 Dual & RB-UL4 Quad Stereo Unbalanced
To Balanced Converters
Introduction
Fig 1-2: RB-UL4 Front Panel.
The RB-UL1 single, RB-UL2 dual & RB-UL4 quad stereo units are used for interfacing
domestic, or semi-pro unbalanced equipment to professional balanced line levels.
All connections are on the rear panel. The RCA unbalanced inputs have an impedance of
10kΩ bridging and are routed to the balanced XLR-3 outputs with an output impedance
of <50Ω.
The RB-UL1 has two inputs & outputs, the RB-UL2 has four inputs & outputs and the RB-UL4
has eight inputs & outputs.
The output gain can be individually adjusted for left and right channels by using pre-set
potentiometers accessible through the rear panel. A LED power indicator on the front panel
displays the power supply connection.
System Block Diagram
Left Input
Consumer/
Unbalanced
Right Input
Consumer/
Unbalanced
Phono
Gain
Phono
Gain
Left Output
Professional/Balanced
Right Output
Professional/Balanced
MATCH I N G CONVERTERS - R B - UL1, RB -UL2, R B - UL4
Fig 1-1: RB-UL1 & RB-UL2 Front Panel.
Fig 1-3: Block Diagram For a Single Channel (x2 for RB-UL2, x4 for RB-UL4).
Redbox User Handbook No 2
1
1
M ATC H I N G CO NVE R T E R S
Rear Panel Connections and Operation
M ATCHING CO NVER TE RS - RB - UL1, RB - U L2 , RB - U L4
RCA
Phono
Inputs
Output
Level
Adjustment
Fig 1-4: RB-UL1 Rear Panel.
RCA
Phono
Inputs
Output
Level
Adjustment
Stereo Balanced
Outputs
Fig 1-5: RB-UL2 Rear Panel.
RCA
Phono
Inputs
Fig 1-6: RB-UL4 Rear Panel.
2
Stereo
Outputs
Output
Level
Adjustment
Stereo Balanced
Outputs
Redbox User Handbook No 2
M ATC HIN G CONVERTERS
1
RCA Phono Inputs (Left and Right)
The stereo left and right RCA inputs are unbalanced and have an impedance of 10kΩ. They
are routed to the stereo balanced XLR 3 pin output connectors.
Outputs (Left and Right)
The XLR 3 pin output plug connectors are electronically balanced with an output
impedance of <50Ω. They have the following connections:
Pin 1: Screen
Pin 2: Phase
Pin 3: Non-phase
Redbox User Handbook No 2
MATCH I N G CONVERTERS - R B - UL1, RB -UL2, R B - UL4
Output Level Adjustment
The output gain can be individually adjusted for left and right channels through
pre-set potentiometers which are accessible through the rear panel. The gain range
of the unbalanced to balanced converter is -15dBu to +15dBu ref -15dBu into the
unbalanced input.
3
1
M ATC H I N G CO NVE R T E R S
MATC HIN G CON VERT ER S - RB - UL1, RB - U L2 , RB - U L4
Technical Specifications
4
Audio Specifications
Maximum Input Level:
Input Impedance:
Output Impedance: Maximum Output Level:
Distortion: Noise:
Common Mode Rejection:
Frequency Response:
Gain Range:
+28dBu
>10kΩ
<50Ω
+28dBu
0.01% THD @ 1kHz ref +8dB output
-100dB unity gain, ref +8dB output
>66dB typically
20Hz to 20kHz ±0.1dB (600Ω load, ref 1kHz)
Balanced output: -15dBu to 15dBu, ref -15dBu into unbalanced RCA input
Connections
Inputs:
Outputs:
Mains Input:
Fuse Rating:
2, 4 (RB-UL2) or 8 (RB-UL4) x RCA phono (unbalanced)
2, 4 (RB-UL2) or 8 (RB-UL4) x XLR 3 pin male (balanced)
Filtered IEC, 110V-120V, or 220-240V switchable, fused,
6W maximum
Anti-surge fuse 100mA 20 x 5mm (230VAC)
Anti-surge fuse 250mA 20 x 5mm (115VAC)
Equipment Type
RB-UL1:
Single stereo unbalanced to balanced converter
RB-UL2:
Dual stereo unbalanced to balanced converter
RB-UL4:
Quad stereo unbalanced to balanced converter
Physical Specifications
RB-UL1 & RB-UL2:
Dimensions (Raw): Dimensions (Boxed): Weight RB-UL1:
Weight RB-UL2:
28cm (W) x 10.8cm (D) x 4.2cm (H) (1U)
36cm (W) x 20.5cm (D) x 6cm (H)
Nett: 1.00kg Gross: 1.45kg
Nett: 1.05kg Gross:
1.5kg
RB-UL4:
Dimensions (Raw):
Dimensions (Boxed):
Weight:
48cm (W) x 10.8cm (D) x 4.2cm (H) (1U)
53cm (W) x 20.5cm (D) x 6cm
Nett: 1.3kg Gross:
1.9kg
Redbox User Handbook No 2
M ATC HIN G CONVERTERS
2
2 RB-LU4 Quad Stereo Balanced To Unbalanced Converter
Introduction
Fig 2-1: RB-LU4 Front Panel.
All connections are on the rear panel. The eight XLR-3 electronically balanced inputs have an
impedance of 20kΩ bridging and are routed to eight unbalanced RCA phono outputs with
an output impedance of <50Ω.
The output gain can be individually adjusted for left and right channels by using pre-set
potentiometers accessible through the rear panel. An LED power indicator is situated on the
front panel, which displays the power supply connection.
Redbox User Handbook No 2
MATCH I N G CONVERTERS - R B - LU4
The RB-LU4 is a quad stereo unit for interfacing professional balanced equipment to
domestic, or semi-pro unbalanced line levels.
5
2
M ATC H I N G CO NVE R T E R S
System Block Diagram
Left Input 1
Professional/
Balanced
MATC HIN G CONVERTE RS - RB - LU 4
Right Input 1
Professional/
Balanced
Left Input 2
Professional/
Balanced
Right Input 2
Professional/
Balanced
Left Input 3
Professional/
Balanced
Right Input 3
Professional/
Balanced
Left Input 4
Professional/
Balanced
Right Input 4
Professional/
Balanced
Phono
Left Output 1
Consumer/Unbalanced
Gain
Phono
Right Output 1
Consumer/Unbalanced
Gain
Phono
Left Output 2
Consumer/Unbalanced
Gain
Phono
Right Output 2
Consumer/Unbalanced
Gain
Phono
Left Output 3
Consumer/Unbalanced
Gain
Phono
Right Output 3
Consumer/Unbalanced
Gain
Phono
Left Output 4
Consumer/Unbalanced
Gain
Phono
Right Output 4
Consumer/Unbalanced
Gain
Fig 2-2: RB-LU4 Block Diagram.
6
Redbox User Handbook No 2
M ATC HIN G CONVERTERS
Rear Panel Connections and Operation
RCA
Phono
Outputs
Output
Level
Adjustment
Fig 2-3: RB-LU4 Rear Panel.
Inputs 1-4 (Left and Right)
The XLR 3 pin sockets used for the left and right channel inputs of Input 1 are electronically
balanced and have an impedance of 20kΩ bridging. They are routed to an unbalanced
RCA (phono) output with an output impedance of <50Ω. Each XLR has the following
connections:
Pin 1: Screen
Pin 2: Phase
Pin 3: Non-phase
RCA Phono Outputs 1-4 (Left and Right)
These RCA (phono) outputs are unbalanced and have an output impedance of <50Ω.
Output Level Adjustment
The output gain can be individually adjusted for left and right channels through pre-set
potentiometers which are accessible through the rear panel. The gain of the balanced to
unbalanced converter is variable within a range of -28dBu to +15dBu ref. -15dBu into the
balanced input.
Redbox User Handbook No 2
MATCH I N G CONVERTERS - R B - LU4
Stereo Balanced
Inputs
2
7
2
M ATC H I N G CO NVE R T E R S
MATC HIN G CONVERTE RS - RB - LU 4
Technical Specifications
8
Audio Specifications
Maximum Input Level:
Input Impedance (XLR):
Output Impedance (RCA) :
Maximum Output Level:
Distortion: Noise:
Common Mode Rejection:
Frequency Response:
Gain Range:
Connections
Inputs:
Outputs:
Mains Input:
Fuse Rating:
+28dBu
>20kΩ balanced bridging
<50Ω
+22dBu
0.01% THD @ 1kHz, ref +8dBu output
-100dB, unity gain, ref +8dBu output
>66dB typically
20Hz to 20kHz ±0.1dB (600Ω load, ref 1kHz)
Unbalanced Output: -28dBu to +15dBu, ref -15dBu into balanced XLR input
8 x XLR 3 pin female (Balanced)
8 x RCA phono (Unbalanced)
Filtered IEC, 110V-120V, or 220-240V switchable, fused, 6W maximum
Anti-surge fuse 100mA 20 x 5mm (230VAC)
Anti-surge fuse 250mA 20 x 5mm (115VAC)
Equipment Type
RB-LU4: Quad stereo balanced to unbalanced converter
Physical Specifications
Dimensions (Raw): Dimensions (Boxed): Weight:
48cm (W) x 10.8cm (D) x 4.2cm (H) (1U)
53cm (W) x 20.5cm (D) x 6cm (H)
Nett: 1.3kg Gross: 1.9kg
Redbox User Handbook No 2
M ATC HIN G CONVERTERS
3
3 RB-BL2 Single & RB-BL4 Dual Bi-Directional
Matching Converter
Introduction
Fig 3-2: RB-BL4 Front Panel.
The RB-BL2 is a bi-directional stereo unit for interfacing domestic, or semi-pro unbalanced
equipment to professional balanced line levels, and vice-versa. The RB-BL4 has dual bidirectional stereo capability.
All connections are on the rear panel. The XLR-3 electronically balanced inputs have an
impedance of 20kΩ bridging and are routed to unbalanced RCA (phono) outputs with an
output impedance of <50Ω.
The RCA unbalanced inputs have an impedance of 10kΩ bridging and are routed to
balanced XLR-3 outputs with an output impedance of <50Ω.
The output gain can be individually adjusted for left and right channels by using pre-set
potentiometers accessible through the rear panel. An LED power indicator on the front
panel displays the power supply connection.
Redbox User Handbook No 2
MATCH I N G CONVERTERS - R B - B L2 & R B - B L4
Fig 3-1: RB-BL2 Front Panel.
9
3
M ATC H I N G CO NVE R T E R S
System Block Diagram
Phono
Left Input 1
Professional/
Balanced
Gain
Phono
MATC HIN G CON VERTERS - RB - BL2 & RB - BL4
Right Input 1
Professional/
Balanced
Left Input 2
Consumer/
Unbalanced
Right Input 2
Consumer/
Unbalanced
Left Output 1
Consumer/Unbalanced
Right Output 1
Consumer/Unbalanced
Gain
Phono
Left Output 2
Professional/Balanced
Gain
Phono
Right Output 2
Professional/Balanced
Gain
Fig 3-3: RB-BL2/BL4 Block Diagram Single Stereo Channel.
(Note RB-BL4 contains 2 of these circuits)
Rear Panel Connections and Operation
Unbalanced Output
Level
Adjustment
Stereo
Balanced
Inputs
Balanced Output
Level
Adjustment
RCA
Phono
Outputs
Stereo
Balanced
Outputs
RCA
Phono
Inputs
Fig 3-4: RB-BL2 Rear Panel.
10
Redbox User Handbook No 2
M ATC HIN G CONVERTERS
RCA
Phono
Outputs
Balanced
Outputs
Balanced RCA Phono
Inputs
Inputs
Balanced
Outputs
RCA Phono
Inputs
Unbalanced Output
Level Control
Balanced Output
Level Control
Fig 3-5: RB-BL4 Rear Panel.
Balanced to Unbalanced Connections
Inputs 1 (& 3) (Left & Right)
The XLR 3 pin sockets used for the left and right channel signals of Inputs 1 & 3 are
electronically balanced and have an impedance of 20kΩ bridging. They are routed to
unbalanced RCA (phono) outputs with an output impedance of <50Ω. Each XLR has the
following connections:
Pin 1: Screen.
Pin 2: Phase.
Pin 3: Non-phase.
RCA Phono Outputs 1 (& 3) (Left & Right)
These RCA (phono) outputs are unbalanced and have an output impedance of <50Ω.
Output Level Adjustment
The output gain can be individually adjusted for left and right channels through pre-set
potentiometers which are accessible through the rear panel. The gain of the balanced
to unbalanced converter is variable within a range of 0dBu to -28dBu ref -0dBu into the
balanced input.
Unbalanced to Balanced Connections
RCA Phono Inputs 2 (& 4) (Left & Right)
The left and right RCA inputs 2 & 4 are unbalanced and have an impedance of 10kΩ.
They are routed to the balanced XLR 3 pin outputs 2 & 4.
MATCH I N G CONVERTERS - R B - B L2 & R B - B L4
Balanced Output
LevelControl
Balanced
Inputs
RCA
Phono
Outputs
3
Outputs 2 (& 4) (Left & Right)
The XLR 3 pin output plug connectors are electronically balanced with an output
impedance of <50Ω. They have the following connections:
Pin 1: Screen.
Pin 2: Phase.
Pin 3: Non-phase.
Redbox User Handbook No 2
11
3
M ATC H I N G CO NVE R T E R S
MATC HIN G CON VERTERS - RB - BL2 & RB - BL4
Technical Specifications
12
Audio Specifications
Maximum Input Level:
Maximum Output Level:
Input Impedance (RCA) :
Input Impedance (XLR) :
Output Impedance (RCA) :
Output Impedance (XLR) : Distortion: Noise:
Common Mode Rejection:
Frequency Response:
Gain Range:
Gain Range:
+28dBu
+28dBu
>10kΩ unbalanced
>20kΩ balanced bridging
<50Ω
<50Ω
0.01% THD @ 1kHz, ref +8dBu output
-100dB, unity gain, ref +8dBu output
>66dB typically
20Hz to 20kHz ±0.1dB (600Ω load, ref 1kHz)
Unbalanced Output: -28dBu to +15dBu, ref -15dBu into
balanced XLR input
Balanced Output: -15dBu to +15dBu, ref -15dBu
into unbalanced RCA input
Connections
Inputs:
Outputs:
Mains Input:
Fuse Rating:
2 (4 on RB-BL4) x XLR 3 pin female (balanced),
2 (4 on RB-BL4) x RCA phono (unbalanced)
2 (4 on RB-BL4) x XLR 3 pin male (balanced),
2 (4 on RB-BL4) x RCA phono (unbalanced)
Filtered IEC, 110V-120V, or 220-240V switchable, fused,
6W maximum
Anti-surge fuse 100mA 20 x 5mm (230VAC)
Anti-surge fuse 250mA 20 x 5mm (115VAC)
Equipment Type
RB-BL2:
Single stereo bi-directional matching converter
RB-BL4:
Dual stereo bi-directional matching converter
Physical Specification
RB-BL2:
Dimensions (Raw): Dimensions (Boxed): Weight:
28cm (W) x 10.8cm (D) x 4.2cm (H) (1U)
36cm (W) x 20.5cm (D) x 6cm (H)
Nett: 1.0kg Gross: 1.4kg
RB-BL4:
Dimensions (Raw)
Dimensions (Boxed)
Weight
48cm (W) x 10.8cm (D) x 4.2cm (H) (1U)
53cm (W) x 20.5cm (D) x 6cm (H)
Nett: 1.3kg Gross: 1.9kg
Redbox User Handbook No 2
M ATC HIN G CONVERTERS
4
4 RB-PA2 Dual Stereo RIAA Phono Amplifier
Introduction
The RB-PA2 is a dual stereo RIAA equalised phono amplifier. This record player preamp
amplifies the small signal from your pick up cartridge (either moving magnet or high output
moving coil magnetic) and provides the necessary RIAA equalisation required for vinyl
records, to match it to a line input of your mixer, or amplifier. It uses a clean RIAA response
making it ideal for use with broadcast turntables and DJ decks and where vinyl records are
being archived to CD for high quality transfers, or for converting albums to mp3.
It operates with phono cartridges with a nominal output of 1mV to 25mV and has been
specifically tested to work with the Technics SL-1200™ and 1210™ range of turntables.
Quality high specification components have been used together with low noise, fast acting
operational amplifiers to produce a superbly transparent signal path. Additionally, the
RB-PA2 runs without a rumble filter to produce a powerful bass response.
The RB-PA2 is a dual stereo unit to interface up to two turntables. The inputs are phono
connectors with Neutrik XLR connectors for the balanced outputs, which may be wired
unbalanced if required. Output gain is individually adjustable for left and right channels in
the range 35dB to 65dB by using pre-set potentiometers. Frequency response is held
within 0.5dB of the RIAA curve and noise is typically better than -84dB RMS A weighted at
40dB gain.
MATCH I N G CONVERTERS - R B - PA2
Fig 4-1: RB-PA2 Front Panel.
System Block Diagram
Left Input
Phono
Phono
Right Input
Phono
RIAA
Gain
RIAA
Gain
Left Output
Professional/Balanced
Right Output
Professional/Balanced
Fig 4-2: RB-PA2 Block Diagram For a Single Stereo Channel.
Redbox User Handbook No 2
13
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M ATC H I N G CO NVE R T E R S
Rear Panel Connections and Operation
MATCH ING CON VERTERS - RB - PA 2
Pick-up
Grounding
Post
RCA
Phono
Inputs
Output
Level
Adjustments
Stereo
Balanced
Outputs
Pick-up
Grounding
Post
RCA
Phono
Inputs
Stereo
Balanced
Outputs
Fig 4-3: RB-PA2 Rear Panel.
RCA Phono Inputs (Left and Right)
The stereo left and right RCA inputs are unbalanced and have an impedance of 47kΩ. They
are routed to the stereo balanced XLR 3 pin output connectors.
Outputs (Left and Right)
The XLR 3 pin output plug connectors are electronically balanced with an output
impedance of <50Ω. They have the following connections:
Pin 1: Screen
Pin 2: Phase
Pin 3: Non-phase
Output Level Adjustment
The output gain can be individually adjusted for left and right channels through pre-set
potentiometers which are accessible through the rear panel. The gain range of each channel
is adjustable between 30dB gain and 58dB gain.
Pick-up Grounding Post
This acts as an earth ground connection to connect to a turntable pick-up ground point.
14
Redbox User Handbook No 2
M ATC HIN G CONVERTERS
4
Technical Specifications
+28dBu
>47kΩ
1mV to 25mV (ref 1kHz)
+28dBu
<50Ω
Adjustable 38dB to 58dB gain via 4 multi-turn pots
Better than -80dBu at 1kHz
10Hz-150kHz (-3dB)
Within 0.5dB of RIAA curve
0.01% THD @ 1kHz, ref +8dBu output
-77dB (CCIR Q-Pk, 20Hz-20kHz)
27dB for 3mV input
90dB
Connections
Inputs:
Outputs:
Earth Tag:
Mains Input:
Fuse Rating:
4 x RCA phono (unbalanced)
4 x XLR 3 pin male (balanced)
Grounding turret tag
Filtered IEC, 110V-120V, or 220-240V switchable,
fused 6W maximum
Anti-surge fuse 100mA 20 x 5mm (230VAC)
Anti-surge fuse 250mA 20 x 5mm (115VAC)
Equipment Type
RB-PA2:
Dual stereo phono amplifier and RIAA gram amplifier
Physical Specifications
Dimensions (Raw): Dimensions (Boxed): Weight RB-PA2
Redbox User Handbook No 2
28cm (W) x 10.8cm (D) x 4.2cm (H) (1U)
36cm (W) x 20.5cm (D) x 6cm (H)
Nett: 1.1kg Gross:
1.5kg
MATCH I N G CONVERTERS - R B - PA2
Audio Specifications
Maximum Input Level:
Input Impedance: Input Sensitivity Range:
Maximum Output Level:
Output Impedance: Output Gain Range:
Crosstalk: Frequency Response:
RIAA Accuracy: Distortion: Noise: Headroom:
Dynamic Range:
15
5
M ATC H I N G CO NVE R T E R S
5 RB-LI2 Stereo Line Isolation Unit
Introduction
MATCH ING CON VERTE RS - RB - LI 2
Fig 5-1: RB-LI2 Front Panel.
The RB-LI2 stereo line isolation unit is used to isolate audio signals from inter area ground
hum loops, which could be caused by equipment being powered by different mains power
supplies, or different phases on the same supply. The input and output are connected
together through a transformer, which has internal jumpers allowing the outputs to be
balanced about ground.
There is also a loop-through output, so that the RB-LI2 can be inserted into a line, forming a
transformer balanced distribution point.
This unit is useful where audio is required to be driven over a relatively long length of cable.
By isolating the signal using transformers, ground loop currents that can be present in nonisolated signals, are eradicated completely.
System Block Diagram
Gain
Input
Ground Link
Jumper
Isolated Output
Loop
Output
Transformer Balanced Mode
X2
Fig 5-2: RB-LI2 System Block Diagram.
16
Redbox User Handbook No 2
M ATC HIN G CONVERTERS
5
Rear Panel Connections and Operation
Isolated
Output
Input
Input
Loop Output
Output Level
Adjustment
Fig 5-3: RB-LI2 Rear Panel.
Inputs
There are 2 input XLR 3 pin sockets. They have the following connections:
Pin 1: Screen
Pin 2: Phase
Pin 3: Non-phase
Isolated Outputs
Each of the 2 inputs has a corresponding isolated output, an XLR 3 pin plug with the
following connections:
Pin 1: Screen
Pin 2: Phase
Pin 3: Non-phase
MATCH I N G CONVERTERS - R B - LI2
Loop Output
Output Level
Adjustment
Isolated
Output
Loop Outputs
Each of the 2 inputs has a corresponding loop-through output, an XLR 3 pin plug with the
following connections:
Pin 1: Screen
Pin 2: Phase
Pin 3: Non-phase
Output Level Adjustment
The isolated outputs can be individually adjusted using pre-set potentiometers, which are
accessible through the rear panel. The gain range of the stereo line isolation unit is -15dB to
+13.5dB (28.5dB).
Redbox User Handbook No 2
17
5
M ATC H I N G CO NVE R T E R S
Internal Jumpers
The unit has jumpers that are used to balance the output about ground. By default these are
not fitted when the unit leaves the factory.
MATCH ING CON VERTE RS - RB - LI 2
To get inside the RB-LI2, first ensure that it has been disconnected from the mains power
and that the mains IEC lead to the unit has been removed. Observing anti-static precautions,
undo the four-crosshead screws on the back panel at the far left and far right of the panel
(2 at each end). Also undo the small brass screws, which hold the top and bottom panels to
the rear panel. The rear panel should slide backwards out of the unit together with the main
circuit board.
Fig 5-4: RB-LI2 Jumper Positions on the PCB.
Technical Specifications
Audio Specification
Output Impedance:
Frequency Response:
Common Mode Rejection:
Distortion: Noise:
Gain Range:
<150Ω
10Hz to 36kHz ±0.5dB
<64dB
0.5% THD @ 40Hz, ref +17dBu output
-100dB unity gain ref +8dB
-15dB to +13.5dB (28.5dB)
Connections
Inputs:
Isolated Outputs:
Loop Outputs:
Fuse Rating:
2 x XLR 3 pin female
2 x XLR 3 pin male
2 x XLR 3 pin male
Anti-surge fuse 100mA 20 x 5mm (230VAC)
Anti-surge fuse 250mA 20 x 5mm (115VAC)
Equipment Type
RB-LI2:
Stereo line isolation unit
Physical Specifications
Dimensions (Raw): Dimensions (Boxed): Weight:
18
28cm (W) x 10.8cm (D) x 4.2cm (H) (1U)
36cm (W) x 20.5cm (D) x 6cm (H)
Nett: 1.10kg Gross: 1.50kg
Redbox User Handbook No 2
M ATC HIN G CONVERTERS
6
6 RB-PLI6 6 Way Mono Passive Line Isolation Unit
Introduction
Fig 6-1: RB-PLI6 Front Panel.
The input and output are connected together through a transformer and the unit has
internal jumpers allowing the inputs and/or outputs to be balanced about ground. The unit
requires no mains power for operation.
This unit is useful where audio is required to be driven over a relatively long length of cable.
By isolating the signal using transformers, ground loop currents that can be present in nonisolated signals, are eradicated completely.
System Block Diagram
Ground Balancing
Input
Output
MATCH I N G CONVERTERS - R B - PLI6
The RB-PLI6 6 way mono passive line isolation unit is used to isolate audio signals from inter
area ground hum loops, which could be caused by equipment being powered by different
mains power supplies or phases on the same supply.
X6
Fig 6-2: RB-PLI6 System Block Diagram.
Redbox User Handbook No 2
19
6
M ATC H I N G CO NVE R T E R S
Rear Panel Connections and Operation
Outputs
M ATCHING CON VERTERS - RB - P LI 6
Inputs
Fig 6-3: RB-PLI6 Rear Panel.
Inputs
There are 6 off XLR 3 pin socket inputs. They have the following connections:
Pin 1: Screen
Pin 2: Phase
Pin 3: Non-phase
Outputs
There are 6 off XLR 3 pin plug outputs. They have the following connections:
Pin 1: Screen
Pin 2: Phase
Pin 3: Non-phase
Ground-link Internal Jumpers
The unit has jumpers that are used to balance either the input, or the output, about ground.
By default these are not fitted when the unit leaves the factory.
To get inside the RB-PLI6, observing anti-static precautions, undo the four crosshead screws
on the back panel at the far left and far right of the panel (2 at each end). Also undo the
small brass screws, which hold the top and bottom panels to the rear panel. The rear panel
should slide backwards out of the unit together with the main circuit board.
Fig 6-4: RB-PLI6 Ground-link Jumper Settings.
20
Redbox User Handbook No 2
M ATC HIN G CONVERTERS
6
Technical Specifications
<150Ω
0.5% THD @ 40Hz, ref +17dBu output
<64dB typically
10Hz to 36kHz ±0.5dB
Connections
Inputs:
Outputs:
6 x XLR 3 pin female (balanced)
6 x XLR 3 pin male (balanced)
Equipment Type
RB-PLI6:
6 way mono passive line isolation unit
Physical Specifications
Dimensions (Raw):
Dimensions (Boxed):
Weight:
48cm (W) x 10.8cm (D) x 4.2cm (H-1U nominally)
53cm (W) x 20.5cm (D) x 6cm
Nett: 1.5kg Gross: 1.9kg
Redbox User Handbook No 2
MATCH I N G CONVERTERS - R B - PLI6
Audio Specification
Output Impedance:
Distortion: Common Mode Rejection:
Frequency Response:
21
7
AU DI O DI S T R I B U T I O N
A M P LI F I E R S
7 RB-DA6 & RB-DA6G 6 Way Stereo Distribution Amplifier
Introduction
AUD IO D ISTR IBUTIO N AM PLIFIERS - RB - DA6 & RB - DA 6 G
Fig 7-1: RB-DA6 Front Panel.
22
Fig 7-2: RB-DA6G Front Panel.
The RB-DA6 and RB-DA6G are high performance 6 way stereo analogue distribution
amplifiers for splitting a source to a number of different outputs. The RB-DA6 has 1 stereo
input and 6 stereo outputs with gain control on both inputs. It can also be configured so
that 1 mono input can be distributed to 12 outputs. As a variant of the RB-DA6, the RBDA6G, has an individual gain control on every output.
The XLR-3 inputs and outputs are electronically balanced and can be wired unbalanced.
Each output is individually buffered so that a short circuit on one won’t affect the others.
The outputs can be wired unbalanced.
The RB-DA6 has master left and right gain controls which are pre- set potentiometers
accessible through the front panel. On the RB-DA6G each channel has an individual output
gain control (normalising) which are all pre-set potentiometers, also accessible through
the front panel. The 1-12 mono, 1-6 stereo switch is recessed on the front panel to prevent
accidental knocking. An LED power indicator on the front panel displays the power supply
connection.
Redbox User Handbook No 2
AUDIO D ISTRIBUTION
AMP LIFIERS
7
System Block Diagrams
Left Outputs
Balanced
1
2
3
4
Right Outputs
Balanced (Mono 7-12)
5
6
1
2
3
4
6
5
6
Left Input
Balanced
Gain
Right
Input
Balanced
Stereo/Mono
Gain
Fig 7-3: RB-DA6 Block Diagram.
Left Outputs
Balanced
1
2
3
4
Left Input
Balanced
Right
Input
Balanced
Stereo/Mono
Fig 7-4: RB-DA6G Block Diagram.
Redbox User Handbook No 2
Right Outputs
Balanced (Mono 7-12)
5
6
1
2
3
4
AU D I O D I S T RIBUTION AM PLIFIER S - R B -DA6 & RB - DA6 G
5
23
7
AU DI O DI S T R I B U T I O N
A M P LI F I E R S
Connections and Operation
AU D IO DISTRIB UTION AMP LIFIERS - RB - DA6 & RB - DA 6 G
Fig 7-5: RB-DA6 & RB-DA6G Rear Panel.
24
Inputs (Left and Right)
The XLR-3 input connectors can take balanced professional levels, or unbalanced by using
the front panel gain controls, and by connecting the non-phase to the signal ground. The
input can be configured as either a stereo input with six stereo outputs or a mono input
with twelve outputs. The XLR 3 pin input has the following connections:
Pin 1: Screen
Pin 2: Phase
Pin 3: Non-phase
Stereo Outputs 1-6 (Mono Outputs 1-12)
The XLR 3 pin outputs are electronically balanced, and can be wired unbalanced. Each
output is individually buffered so that a short circuit on one output will not affect the others.
They have the following connections:
Pin 1: Screen
Pin 2: Phase
Pin 3: Non-phase
Input Gain Control (RB-DA6)
The input gain on the RB-DA6 can be varied –8dB to 18db by adjusting the pre-set
potentiometers. These are accessible through the holes in the front panel. The RB-DA6 has
separate left and right master gain controls.
Input Stereo/
Gain
Mono
Controls Switch
Fig 7-6: RB-DA6 Front Panel.
Output Gain Control (RB-DA6G)
The output gain on the RB-DA6G can be varied –8dB to 18dB by adjusting the pre-set
potentiometers. These are accessible through the holes in the front panel. The RB-DA6G has
output gain controls on every output.
Redbox User Handbook No 2
AUDIO D ISTRIBUTION
AMP LIFIERS
Output Gain Controls
7
Stereo/
Mono
Switch
Fig 7-7: RB-DA6G Front Panel.
Technical Specifications
Audio Specifications
Input Impedance Output Impedance Maximum Input Level
Maximum Output Level
Frequency Response
Gain Range
Common Mode Rejection
Distortion
Noise
>20kΩ bridging
<50Ω
+28dBu
+28dBu
20Hz to 20kHz ± 0.1dB (600Ω load, ref 1kHz)
Adjustable 8dB loss to 18dB gain
>66dB typically
0.01% THD @ 1kHz, ref +8dBu output
-100dB unity gain ref +8dB (RB-DA6)
-88dB unity gain ref +8dB (RB-DA6G)
Connections
Inputs
Outputs
Mains Input
Fuse Rating:
2 x XLR 3 pin female (Balanced, can be unbalanced)
12 x XLR 3 pin male (Balanced, can be unbalanced)
Filtered IEC, 110V-120V, or 220-240V, fused, 6W maximum
Anti-surge fuse 100mA 20 x 5mm (230VAC)
Anti-surge fuse 250mA 20 x 5mm (115VAC)
Equipment Type
RB-DA6:
RB-DA6G:
6 way stereo distribution amplifier
6 way stereo distribution amplifier with output gain
Physical Specifications
Dimensions (Raw): Dimensions (Boxed): Weight:
48cm (W) x 10.8cm (D) x 4.2cm (H) (1U)
53cm (W) x 20.5cm (D) x 6cm (H)
Nett: 1.3kg Gross: 1.9kg
Redbox User Handbook No 2
AU D I O D I S T RIBUTION AM PLIFIER S - R B -DA6 & RB - DA6 G
Stereo/Mono Operation
The mode of operation may be switched between a stereo distributed channel to 6 stereo
channels, and a mono channel to 12 mono channels, by the push button on the front panel,
which is recessed to prevent accidental switching.
25
8
AU DI O DI S T R I B U T I O N
A M P LI F I E R S
8 RB-DA4x5 4 Input 4 x 5 Output Distribution Amplifier/Mixer
Introduction
AUDIO D ISTR IBUTIO N AMP LIFIERS - RB - DA 4 x5
Output
Input
Gain
Gain
Input
Controls Selectors Controls
26
Input/
Output
Levels
Fig 8-1: RB-DA4x5 Front Panel.
The RB-DA4x5 is a 1U rack-mount combined distribution amplifier and mixer. It has 4
mono analogue audio inputs on female XLR and 4 groups of 5 outputs on 15 way D-type
connectors. Each output group has a five way front-panel DIP switch assigned to it which is
used to select the input(s) to send to the output group. This enables each of the four inputs,
and a 1kHz 0dBu tone, to be mixed to the output group.
The inputs and outputs are electronically balanced and can be wired unbalanced. Each
input has adjustable gain using a preset potentiometer, providing a gain range of -8dB to
+18dB. Each output is individually buffered so that a short circuit on one output will not
affect the others. The output gain of each group can similarly be adjusted between -8dB and
+18dB using preset potentiometers.
The DIP switch settings and gain controls are recessed beneath a front-mounting screw-on
cover so that settings can not be accidentally altered, for secure applications. Four bright
front-panel signal present LEDs show the levels of either the inputs or the output groups by
pressing the AUDIO PRESENCE button. The LEDs will show green illumination from -12dBu
through to 0dBu, amber from 0dBu through to +6dBu and red for inputs and outputs at
+6dBu and over.
Redbox User Handbook No 2
AUDIO D ISTRIBUTION
AMP LIFIERS
8
System Block Diagram
Balanced XLR
Input 1
Gain
Balanced XLR
Input 2
Gain
Balanced XLR
Input 3
Output 1
Switch Bank
Gain
Gain
Meter 1
Output
Gain
Meter 2
Output
Gain
Reference
Tone
Meter In 2
Meter Out 1
Meter Out 2
Meter 1
Meter 2
Meter In 3
Meter In 4
Meter Out 3
Meter Out 4
Meter 3
Output 1
Switch Bank
Gain
Meter 3
Output
Meter 4
Output 1
Switch Bank
Gain
Meter 4
Output
Fig 8-2: RB-DA4x5 Block Diagram.
Rear Panel Connections and Operation
Inputs
Outputs
Fig 8-3: RB-DA4x5 Rear Panel.
Audio Inputs 1-4
The XLR 3 pin sockets used for the audio inputs are electronically balanced and have
an impedance of 20kΩ bridging. They are routed to the switch matrix. Each XLR has the
following connections:
AU D I O D I S T RIBUTION AM PLIFIER S - R B -DA4x5
Balanced XLR
Input 4
Meter In 1
Output 1
Switch Bank
Pin 1: Screen
Pin 2: Phase
Pin 3: Non-phase
Redbox User Handbook No 2
27
8
AU DI O DI S T R I B U T I O N
A M P LI F I E R S
AUDIO D ISTR IBUTIO N AMP LIFIERS - RB - DA 4 x5
D-Type Audio Output Groups 1-4
Each output group connector has 5xDA driven balanced audio outputs on a D-type
connector outputs each with an output impedance of <50Ω.
Output 2
1
8
9
15
Output 1
Output 4
Output 3
Output 5
Fig 8-4: RB-DA4x5 Audio Output Group15-Way D-Type Plug.
Function
Out + Pin No.
Out - Pin No.
Signal Ground Pin No.
Output 1
1
9
2
Output 2
3
10
11
Output 3
4
12
5
Output 4
6
13
14
Output 5
7
15
8
Fig 8-5: RB-DA4x5 Pinout for Audio Output Group Connector.
Monitor LEDs
There are 4 LEDs on the front panel that indicate the relative levels of the audio signals at
the inputs or outputs. A pushbutton switch on the front panel toggles the function of these
LEDs between input and output. These LEDs indicate the levels of the signals by illuminating
green for signals between –12 and 0dBu, illuminating yellow for signals between 0 and
+6dBu, and illuminating red for signals over +6dBu.
Input Level Adjustment
The gain for each input can be adjusted through pre-set potentiometers that are accessible
from behind the removable plate on the front panel. The gain of each balanced input is
variable within a range of -8dB to +18dB into the router input.
Output Level Adjustment
The gain for each output group can be adjusted through pre-set potentiometers that are
accessible from behind the removable plate on the front panel. The gain of each output
group is variable within a range of -8dB to +18dB from the router output.
Routing Selection
Each output group is capable of selecting its signal from any combination of inputs and the
test tone. Set the appropriate dip-switch for that group & that input to the on position to
include the signal in the group’s output.
OUTPUT 1 OUTPUT 2
TEST TONE TEST TONE
1 2 3 4 l 1 2 3 4 l
1
2
3
4
5
6
7
8
9
10
On $
On
Fig 8-6: RB-DA4x5 Routing Selection Switch.
28
Redbox User Handbook No 2
AUDIO D ISTRIBUTION
AMP LIFIERS
Function
Input 1
Input 2
Input 3
Input 4
Test Tone
Group 1
Routing
SW1-1 On
SW1-2 On
SW1-3 On
SW1-4 On
SW1-5 On
Group 2
Routing
SW1-6 On
SW1-7 On
SW1-8 On
SW1-9 On
SW1-10 On
Group 3
Routing
SW2-1 On
SW2-2 On
SW2-3 On
SW2-4 On
SW2-5 On
8
Group 4
Routing
SW2-6 On
SW2-7 On
SW2-8 On
SW2-9 On
SW2-10 On
Fig 8-7: RB-DA4x5 Routing Selection Switch Functions.
Technical Specifications
Audio Specifications
Maximum Input Level:
Input Impedance (XLR):
Output Impedance: Maximum Output Level:
Distortion: Noise:
Common Mode Rejection:
Frequency Response:
Input Gain Range:
Output Gain Range:
+28dBu
>20kΩ balanced bridging
<50Ω
+28dBu
0.01% THD @ 1kHz, ref +8dBu output
-100dB, unity gain, ref +8dBu output
>66dB typically
20Hz to 20kHz ±0.1dB (600Ω load, ref 1kHz)
Adjustable 8dB loss to 18dB gain (channel 1-4 adjust)
Adjustable 8dB loss to 18dB gain (group 1-4 adjust)
Connections
Inputs (4 x mono):
Outputs (20 x mono):
Mains Input:
Fuse Rating:
4 x XLR 3 pin female (Balanced)
4 x 15 way D-type (Balanced)
Filtered IEC, 110V-120V, or 220-240V switchable,
fused, 9W maximum
Anti-surge fuse 100mA 20 x 5mm (230VAC)
Anti-surge fuse 250mA 20 x 5mm (115VAC)
Equipment Type
RB-DA4x5: 4 input to 20 output distribution amplifier & mixer
Physical Specifications
Dimensions (Raw): Dimensions (Boxed): Weight:
48cm (W) x 15.8cm (D*) x 4.2cm (H) (1U)
53cm (W) x 25.5cm (D*) x 6cm (H)
Nett: 1.6kg Gross: 2.2kg
AU D I O D I S T RIBUTION AM PLIFIER S - R B -DA4x5
Alignment Test Tone
Each of the output groups has the capability of selecting a 1kHz, 0dBu test tone. This signal
can be used as a reference to set the output gain levels. Once these values are known then
the input gains can be set by providing a known tone to the input and adjusting the input
gain to the required level. It is possible to use this test tone as a reference level for the input
gain by adjusting the output gains to unity and then looping back any output to the input
connector. The on-board oscillator is temperature sensitive and in cold conditions may take
a short time to start oscillating. In any case you should always allow the unit to fully come to
its normal operating temperature before adjusting the gains.
* Note that this product is deeper than standard redboxes.
Redbox User Handbook No 2
29
9
AU DI O DI S T R I B U T I O N
A M P LI F I E R S
9 RB-DDA6A 6 Way Stereo AES/EBU Digital Distribution Amplifier
and RB-DDA6S 6 Way Stereo S/PDIF Digital Distribution
Amplifier
AU D IO DIS TR IBUTIO N AM PLIFIE RS - RB - D DA6A & RB - D DA 6 S
Introduction
30
Fig 9-1: RB-DDA6A/S Front Panel.
192
The RB-DDA6A digital distribution amplifier is used for distributing digital
audio data in AES/EBU format, repeating both the audio data and the status
information of the input whilst re-normalising to standard digital audio levels.
It has a single XLR-3 female AES/EBU audio input which is distributed to 6 XLR-3 male
AES/EBU outputs.
Applications include distributing audio from a digital mixing desk to multiple digital
recorders, or feeding multiple studios with an output from a DAT machine.
It can accept input sample rates in the range of 30kHz - 100kHz, and bit rates of 16, 20 and
24 bit. So, it can be used for standard CD signal distribution at 16 bit 44.1kHz, as well as for
high quality 24 bit 96kHz recording.
The RB-DDA6S digital distribution amplifier is similar to the RB-DDA6A except that it is used
for distributing digital audio data in S/PDIF format.
It has a single S/PDIF audio input which is distributed to 6 x S/PDIF audio outputs at the
same level and condition as the input signal. It can accept input sample rates in the range of
30kHz - 100kHz, and bit rates of 16, 20 and 24 bit.
Uses include audio distribution at 16 bit 44.1kHz from a consumer CD player to multiple
digital recorders, distribution of high quality 24 bit 96kHz signals from digital mixing desks
to recorders and connection of the output of, say, a DVD player to multiple studios.
Redbox User Handbook No 2
AUDIO D ISTRIBUTION
AMP LIFIERS
9
System Block Diagrams
Output XLR-3
Male
AES/EBU
Transmitter
Output XLR-3
Male
Output XLR-3
Male
AES/EBU
Transmitter
Input XLR-3
Female
AES/EBU
Receiver
Output XLR-3
Male
AES/EBU
Transmitter
Output XLR-3
Male
AES/EBU
Transmitter
Output XLR-3
Male
AES/EBU
Transmitter
Fig 9-2: RB-DDA6A System Block Diagram.
Redbox User Handbook No 2
AU D I O D I S T RIBUTION AM PLIFIER S - RB - DDA6A & R B - D DA 6 S
AES/EBU
Transmitter
31
9
AU DI O DI S T R I B U T I O N
A M P LI F I E R S
Output
RCA Phono
S/PDIF
Transmitter
AU D I O D ISTR IB UTION AMP LIFIER S - RB - D DA6A & RB - D DA 6 S
Output
RCA Phono
32
S/PDIF
Transmitter
Output
RCA Phono
S/PDIF
Transmitter
Input
RCA Phono
S/PDIF
Receiver
Output
RCA Phono
S/PDIF
Transmitter
Output
RCA Phono
S/PDIF
Transmitter
Output
RCA Phono
S/PDIF
Transmitter
Fig 9-3: RB-DDA6S System Block Diagram.
Redbox User Handbook No 2
AUDIO D ISTRIBUTION
AMP LIFIERS
9
Rear Panel Connections and Operations
AES/EBU
Input
AES/EBU
Outputs
AES/EBU Input
The XLR 3 pin socket has an impedance of 110Ω. It has the following connections:
Pin 1: Screen
Pin 2: Phase
Pin 3: Non-phase
AES/EBU Outputs
The XLR 3 pin sockets have an impedance of 110Ω. They have the following connections:
Pin 1: Screen
Pin 2: Phase
Pin 3: Non-phase
S/PDIF
Input
S/PDIF
Outputs
Fig 9-5: RB-DDA6S Rear Panel.
S/PDIF Input
The S/PDIF phono input has an impedance of 75Ω.
S/PDIF Outputs
The S/PDIF phono outputs have an impedance of 75Ω.
Redbox User Handbook No 2
AU D I O D I S T RIBUTION AM PLIFIER S - RB - DDA6A & R B - D DA 6 S
Fig 9-4: RB-DDA6A Rear panel.
33
9
AU DI O DI S T R I B U T I O N
A M P LI F I E R S
AU D I O D ISTR IB UTION AMP LIFIER S - RB - D DA6A & RB - D DA 6 S
Technical Specifications
34
Audio Specifications
RB-DDA6A
Input Impedance: Output Impedance: Sample Freq Range:
Signal Level:
110Ω ± 20% balanced
110Ω ± 20% balanced
30-100kHz (i.e. including 32kHz, 44.1kHz, 48kHz, 64kHz, 88.2kHz and 96kHz)
3V/10V peak to peak min/max
RB-DDA6S
Input Impedance: Output Impedance: Sample Freq Range:
Signal Level:
75Ω ±5% unbalanced
75Ω ±5% unbalanced
30-100kHz (i.e. including 32kHz, 44.1kHz, 48kHz, 64kHz, 88.2kHz and 96kHz)
Balanced min 0.5V ±20% peak to peak
Connections
RB-DDA6A
Input:
Outputs:
Mains Input
Fuse Rating:
1 x AES/EBU XLR 3 pin female (balanced)
6 x AES/EBU XLR 3 pin male (balanced)
Filtered IEC, 110-120V, or 220-240V switchable,
fused, 6W max
Anti-surge fuse 100mA 20 x 5mm (230VAC)
Anti-surge fuse 250mA 20 x 5mm (115VAC)
RB-DDA6S
Input (unbalanced):
Outputs:
Mains Input:
Fuse Rating:
1 x S/PDIF RCA phono female
6 x S/PDIF RCA phono female (unbalanced)
Filtered IEC, 110-120V, or 220-240V switchable,
fused, 6W max
Anti-surge fuse 100mA 20 x 5mm (230VAC)
Anti-surge fuse 250mA 20 x 5mm (115VAC)
Equipment Type
RB-DDA6A
RB-DDA6S
6 way AES/EBU stereo digital distribution amplifier
6 way stereo S/PDIF digital distribution amplifier
Physical Specifications
RB-DDA6A
Dimensions (Raw):
Dimensions (Boxed):
Weight:
28cm (W) x 10.8cm (D) x 4.2cm (H) (1U)
36cm (W) x 20.5cm (D) x 6cm (H)
Nett: 0.95kg Gross: 1.4kg
RB-DDA6S
Dimensions (Raw):
Dimensions (Boxed):
Weight:
28cm (W) x 10.8cm (D) x 4.2cm (H) (1U)
36cm (W) x 20.5cm (D) x 6cm (H)
Nett: 0.9kg Gross: 1.35kg
Redbox User Handbook No 2
AUDIO D ISTRIBUTION
AMP LIFIERS
10
10 RB-DDA6W 6 Way Word Clock Distribution Amplifier
Introduction
The RB-DDA6W 6 Way Word Clock Distribution Amplifier distributes a word clock BNC input
signal to 6 word clock BNC outputs re-conditioned. It is used in distributing reference clocks
for digital audio systems.
It has a single female BNC input which is distributed to 6 female BNC outputs.
The unit’s primary application is to distribute a master TTL word clock source to multiple
pieces of equipment that need to be synchronised from the master.
Redbox User Handbook No 2
AU D I O D I S T RIBUTION AM PLIFIER S - R B -D DA6W
Fig 10-1: RB-DDA6W Front Panel.
35
10
AU DI O DI S T R I B U T I O N
A M P LI F I E R S
System Block Diagram
Output
BNC
TTL
Transmitter
AUD IO DISTRIB UTION AMP LIFIERS - RB - D DA 6 W
Output
BNC
36
TTL
Transmitter
Output
BNC
TTL
Transmitter
Input
BNC
TTL
Receiver
Output
BNC
TTL
Transmitter
Output
BNC
TTL
Transmitter
Output
BNC
TTL
Transmitter
Fig 10-2: RB-DDA6W System Block Diagram.
Redbox User Handbook No 2
AUDIO D ISTRIBUTION
AMP LIFIERS
10
Rear Panel Connections and Operations
Word Clock
Input
Word Clock
Outputs
Word Clock Input
The Word Clock BNC input has an impedance of 75 Ω.
Word Clock Outputs
The Word Clock BNC outputs have an impedance of <50 Ω.
Technical Specifications
Signal Specifications
Input Impedance Output Impedance 75Ω
<50Ω
Connections
Input
Outputs
Mains Input
Fuse Rating:
1 x BNC female
6 x BNC female
Filtered IEC, 110-120V, or 220-240V switchable,
fused, 6W max
Anti-surge fuse 100mA 20 x 5mm (230VAC)
Anti-surge fuse 250mA 20 x 5mm (115VAC)
Equipment Type
RB-DDA6W
6 way word clock distribution amplifier
Physical Specifications
Dimensions (Raw)
Dimensions (Boxed)
Weight
Redbox User Handbook No 2
28cm (W) x 10.8cm (D) x 4.2cm (H) (1U)
36cm (W) x 20.5cm (D) x 6cm (H)
Nett:
0.9kg
Gross:
1.35kg
AU D I O D I S T RIBUTION AM PLIFIER S - R B -D DA6W
Fig 10-3: RB-DDA6W Rear Panel.
37
11
H E A D P H O NE DISTRIBUTION
A M P LI F I E R S
11 RB-HD1 Stereo Headphone Amplifier &
RB-HD2 Dual Headphone Amplifier
Introduction
HEADPHONE DISTRIBUTION AMPLIFIERS-RB-HD1 & RB-HD2
Fig 11-1: RB-HD1 Front Panel.
38
The RB-HD1 is a 1U rack-mount stereo headphone amplifier for driving up to two pairs of
professional stereo headphones from a single stereo or mono input. One headphone socket
is on the front panel with one on the rear.
The main stereo input uses electronically balanced XLR-3 connectors on the rear panel,
which can be wired un-balanced. The output volume for the headphones can be controlled
either by a pot situated on the front panel or a VCA signal supplied externally via the remote
connector.
A mono input can be mixed into the main headphone feed, for example, for mixing in
talkback to the headphones. This has an input level control via a recessed adjustable
potentiometer. The mono mix input can also be controlled remotely.
A stereo/mono switch is recessed on the rear panel to prevent accidental knocking. With
mono selected, audio is sent to both left and right ear pieces. A LED power indicator on the
front panel displays the power supply connection.
Fig 11-2: RB-HD2 Front Panel.
The RB-HD2 is a high performance 2-way stereo headphone distribution amplifier for
driving up to 2 pairs of professional stereo headphones from a single stereo or mono input.
A switch on the rear panel enables the distribution of a mono signal to all four outputs (i.e.
both earpieces of a pair of stereo headphones) via the left channel input. The stereo/mono
switch is located on the rear panel to prevent accidental knocking.
The XLR-3 inputs are electronically balanced and can be wired unbalanced. There are two
pre-set controls on the rear panel that adjust the level of the master input signal to the
outputs.
Each output is on a ¼” stereo jack socket and is designed to drive 150mW into 32 ohm to
600 ohm stereo headphones. The outputs are individually buffered with their own front
panel volume control. A LED power indicator on the front panel displays the power supply
connection.
Redbox User Handbook No 2
HEADPHONE DISTRIBUTION
AMP LIFIERS
11
System Block Diagrams
Left Input
Audio XLR
Audio Input
Amplifier
Stereo Jack
Output
VCA
Audio Output
Amplifier
Right Input
Audio XLR
Stereo/Mono
Control Switch
Input
Mono
Mix
Gain
Remote Connector
Stereo Jack
Output
Local/Remote
Control Switch
Volume
Fig 11-3: RB-HD1 Block Diagram.
XLR
Master
Input
Audio Input
Amplifier
Volume
Audio
Output
Amp
Stereo
Jack
Output
Stereo
Push
Switch
Stereo/Mono
Control Switch
Fig 11-4: RB-HD2 Block Diagram.
Redbox User Handbook No 2
Audio
Output
Amp
Volume
Stereo
Jack
Output
HEADPHONE DISTRIBUTION AMPLIFIERS-RB-HD1 & RB-HD2
Push
Switch
39
11
H E A D P H O NE DISTRIBUTION
A M P LI F I E R S
Front Panel Connections and Controls
HEADPHONE DISTRIBUTION AMPLIFIERS-RB-HD1 & RB-HD2
Volume
Stereo Level
Output Control
40
Fig 11-5: RB-HD1 Front Panel Controls.
Stereo Outputs 1-2 (Mono Outputs1-2)
The outputs available on the front and rear panel through ¼” stereo jack sockets are pushpull, designed to drive 150 mW into 32Ω to 600Ω professional headphones. Each output is
individually buffered.
Volume Level Control
The volume level control sets the output level of the two stereo headphone sockets.
The two headphone outputs have a maximum output of +11dBu.
Stereo
Output
Stereo
Output
Volume Volume
Level
Level
Control Control
Fig 11-6: RB-HD2 Front Panel Controls.
Stereo Outputs 1-2 (Mono Outputs 1-2)
The outputs available on the front panel through ¼” stereo jack sockets are push-pull,
designed to drive 150 mW into 32Ω to 600Ω professional headphones. Each output is
individually buffered.
Channel Volume Controls
Each channel has its own volume control so that you have control of the signal volume to an
individual output from the master input.
Redbox User Handbook No 2
HEADPHONE DISTRIBUTION
AMP LIFIERS
11
Rear Panel Connections and Operation
Main
Stereo
Inputs
Mono
Mix
Input
Mono Mix Input
Gain Adjustment
Remote
Connector
Local/ Remote
Control Switch
Fig 11-7: RB-HD1 Rear Panel.
Main Stereo
Inputs
Stereo/
Mono Switch
Stereo Input Gain Adjustment
Fig 11-8: RB-HD2 Rear Panel.
Main Stereo Inputs (Left and Right)
The XLR-3 input connectors can take balanced professional levels, or unbalanced by using
the volume control to increase the input level, and by connecting the non-phase to the
signal ground. The input can be configured as either a stereo input with two stereo outputs
or a mono input with two mono paired outputs. The XLR 3 pin input has the following
connections:
Pin 1: Screen
Pin 2: Phase
Pin 3: Non-phase
Stereo Input Gain Adjustment (RB-HD1)
There are two preset controls on the rear panel that adjust the level of the master input
signal to the outputs from -12dB to +20dB gain.
Redbox User Handbook No 2
HEADPHONE DISTRIBUTION AMPLIFIERS-RB-HD1 & RB-HD2
Stereo/ Mono
Switch
Headphone
41
11
H E A D P H O NE DISTRIBUTION
A M P LI F I E R S
HEADPHONE DISTRIBUTION AMPLIFIERS-RB-HD1 & RB-HD2
Stereo/Mono Operation
The mode of operation may be switched between a stereo distributed channel to 2 stereo
channels, or a mono channel to two mono paired outputs (i.e. the same signal to both
ear pieces) by using the push button, mounted on the rear panel to prevent accidental
switching.
42
Mono Mix Input (RB-HD1)
The XLR-3 input connector can take balanced professional levels, or unbalanced by
connecting the non-phase to the signal ground. This input is used for mixing with the main
stereo input, which is controlled by the MIX_EN pin (pin 8 on the remote connector) on
the remote connector. While this signal is shorted to the ground pin (pin 9 on the remote
connector) mixing is enabled and is only disabled once the signal from MIX_EN to pin 9 is
open on the remote connector. The XLR 3 pin input has the following connections:
Pin 1: Screen
Pin 2: Phase
Pin 3: Non-phase
Mono Mix Input Gain Adjustment (RB-HD1)
A rotary pre-set potentiometer can be used to adjust the gain of the mono mix input by
22dBu.
Local/Remote Control Operation (RB-HD1)
The level to the two outputs can be controlled in one of two ways, either locally, by the pot
situated on the front panel or remotely, by a VCA signal supplied externally to the remote
connector.
Remote Connector (RB-HD1)
The remote connector is a 9-pin D-type socket, which is situated on the rear panel. It has
connections as shown below.
Pin No.
Pin 1
Pin 2
Pin 3
Pin 4
Pin 5
Pin 6
Pin 7
Pin 8
Pin 9
Signal
Pot wiper
Pot top
N/C
N/C
N/C
Pot bottom
N/C
MIX_EN
0V
I/O
I
O
I
-
Description
Volume control signal
+5V
No connection
No connection
No connection
Ground
No connection
Make to pin 9
Ground
Fig 11-9: RB-HD1 Remote Connector
Redbox User Handbook No 2
HEADPHONE DISTRIBUTION
AMP LIFIERS
11
Technical Specifications
Audio Specifications RB-HD1 & RB-HD2:
Maximum Input Level:
+28dBu
Input Impedance: >20kΩ balanced bridging (main)
Input Gain Range:
-12dB to +20dB (pre-set pots) (RB-HD2)
Output Level:
Drives 150 mW into 32Ω to 600Ω headphones
Volume Control:
-80dB to +11dB gain
Mono Mix Input Gain Range: 22dBu (RB-HD1)
2 x XLR 3 pin female (Balanced, can be wired unbalanced)
1 x XLR 3 pin female (Balanced, can be wired unbalanced)
2 x ¼” (6.35mm) A/B gauge 3-pole stereo jack sockets
9-pin D-type socket
Filtered IEC, 110V-120V, or 220-240V switchable, fused, 9W maximum
Anti-surge fuse 100mA 20 x 5mm (230VAC)
Anti-surge fuse 250mA 20 x 5mm (115VAC)
RB-HD2:
Main Stereo Input
Outputs
Mains Input
Fuse Rating:
2 x XLR 3 pin female (Balanced, can be wired unbalanced)
2 x ¼” (6.35mm) A/B gauge 3-pole stereo jack sockets
Filtered IEC, 110V-120V, or 220-240V, fused, switchable, 9W maximum
Anti-surge fuse 100mA 20 x 5mm (230VAC)
Anti-surge fuse 250mA 20 x 5mm (115VAC)
Equipment Type
RB-HD1: RB-HD2:
Stereo headphone amplifier
Dual stereo headphone amplifier
Physical Specifications
RB-HD1:
Dimensions (Raw):
Dimensions (Boxed):
Weight:
48cm (W) x 10.8cm (D) x 4.2cm (H) (1U)
53cm (W) x 20.5cm (D) x 6cm
Nett: 1.35kg Gross: 2.0kg
RB-HD2:
Dimensions (Raw):
Dimensions (Boxed):
Weight:
48cm (W) x 10.8cm (D) x 4.2cm (H) (1U)
53cm (W) x 20.5cm (D) x 6cm
Nett: 1.35kg Gross: 2.0kg
Redbox User Handbook No 2
HEADPHONE DISTRIBUTION AMPLIFIERS-RB-HD1 & RB-HD2
Connections
RB-HD1:
Main Stereo Input:
Mono Mix Input:
Outputs:
Remote Control:
Mains Input:
Fuse Rating:
43
12
H E A D P H O NE DISTRIBUTION
A M P LI F I E R S
12 RB-HD6 6 Way Headphone Distribution Amplifier
Introduction
HE ADPHO NE DISTRIB UTION AMP LIFIERS - RB - H D 6
Fig 12-1: RB-HD6 Front Panel.
44
The RB-HD6 is a high performance 6-way stereo headphone distribution amplifier for
driving up to 6 pairs of professional stereo headphones from a single stereo or mono input.
A switch on the rear panel enables the distribution of a mono signal to all twelve outputs
(i.e. both earpieces of a pair of stereo headphones) via the left channel input.
Alternatively, the RB-HD6 can be used as six separate stereo headphone amplifiers by
using the override (insert-point, or break-jack) input associated with each outlet. A typical
application might be to provide common headphone feeds for guests around a table in a
radio studio, with a separately derived feed, perhaps including talkback, for the presenter.
The over-ride inputs can also be configured as parallel outputs (to the front outputs) by
altering jumper settings inside the unit.
The XLR-3 inputs are electronically balanced and can be wired unbalanced. There is a master
control that adjusts the level of the master signal to all the outputs. This master control can
be disabled by the use of internal jumpers. Each output is designed to drive 150 mW into
32Ω to 600Ω stereo headphones and is individually buffered with its own volume control.
The input level and output volume controls are all potentiometers on the front panel.
The stereo/mono switch is recessed on the rear panel to prevent accidental knocking.
A LED power indicator on the front panel displays the power supply connection.
Redbox User Handbook No 2
HEADPHONE DISTRIBUTION
AMP LIFIERS
12
System Block Diagram
Redbox User Handbook No 2
H E A D P H ON E D ISTRIBUTION AMP LIFIER S - R B - H D 6
Fig 12-2: RB-HD6 Block Diagram.
45
12
H E A D P H O NE DISTRIBUTION
A M P LI F I E R S
Rear Panel Connections and Operation
HEAD PH ON E D IST RIB UTION AMP LIFIERS - RB - H D 6
Stereo
Inputs
46
Channel Insertion Inputs
Stereo/
Mono
Operation
Fig 12-3: RB-HD6 Rear Panel.
Stereo Input (Left and Right)
The XLR-3 input connectors can take balanced professional levels, or unbalanced by using
the front panel master control to increase the input level, and by connecting the nonphase to the signal ground. The input can be configured as either a stereo input with six
stereo outputs or a mono input with six mono paired outputs. The XLR 3 pin input has the
following connections:
Pin 1: Screen
Pin 2: Phase
Pin 3: Non-phase
Stereo/Mono Operation
The mode of operation may be switched between a stereo distributed channel to 6 stereo
channels, or a mono channel to six mono paired outputs (i.e. the same signal to both ear
pieces), by the push button on the rear panel which is recessed to prevent accidental
switching.
Channel Insertion Inputs/Parallel Outputs
Each channel has an unbalanced override/insertion input via a ¼” stereo audio jack socket
on the rear panel, which overrides the master input.
Each connector can also be individually configured as a parallel output providing the same
signal as the output on the front of the unit. To configure the jack connector as an output,
you’ll need to alter some jumper settings inside the unit.
Removing the Equipment Covers
To get inside the RB-HD6, first ensure that it has been disconnected from the mains power
and that the mains IEC lead to the unit has been removed. Observing anti-static precautions,
undo the four cross-head screws on the back panel at the far left and far right of the panel
(2 at each end). Also undo the small brass screws which hold the top and bottom panels to
the rear panel. The rear panel should slide backwards out of the unit together with the main
circuit board.
Redbox User Handbook No 2
HEADPHONE DISTRIBUTION
AMP LIFIERS
12
Configuring Insert Inputs/Parallel Outputs
On the main circuit board, you’ll see some jumpers (small black rectangles), the position of
which will define whether a particular jack socket operates as an input or output.
The drawings below show the different jumper settings available. Each input/output can
be configured individually, so you could have three jacks set as inputs and three as outputs
if needed.
Input/Output
Jumpers Left
to Alter Right
1
JP1 & 2
JP3 & 4
2
JP5 & 6
JP7 & 8
3
JP9 & 10
JP11 & 12
4
JP13 & 14
JP15 & 16
5
JP17 & 18
JP19 & 20
6
JP21 & 22
JP23 & 24
Fig 12-5: RB-HD6 Jumper Positions.
Once you’ve set up the jumpers, slide the circuit board back into the Redbox housing using
the slots along the inside edge of the metalwork as a guide. Replace the screws on the top,
bottom and rear panels of the RB-HD6.
Important Note : The screws provide earthing protection to the chassis and grounding
protection for CE approval – it is important that you reinsert all the screws provided.
Front Panel Connections and Controls
Volume
Controls
Master
Volume Control
Headphone Outputs
Fig 12-6: RB-HD6 Front Panel Controls.
H E A D P H ON E D ISTRIBUTION AMP LIFIER S - R B - H D 6
Fig 12-4: RB-HD6 Jumper Assignments.
Stereo Outputs 1-6 (Mono Outputs 1-6)
The outputs available on the front panel through ¼” stereo jack sockets are push-pull,
designed to drive 150 mW into 32Ω to 600Ω professional headphones. Each output is
individually buffered.
Redbox User Handbook No 2
47
12
H E A D P H O NE DISTRIBUTION
A M P LI F I E R S
Master Level Control
The master level control will set the maximum level of all channels and will need to be
set high if an unbalanced consumer input level (-10dbu) is used. This level control can
be disabled by setting jumpers within the unit. See Page 46 for details on removing
the equipment covers. The two jumpers JP25 and JP26 can be found near the volume
potentiometer VR1 :
HEAD P HON E D ISTR IBUTION AMP LIFIERS - RB - H D 6
Jumper
Enable Master Level Control
Disable Master Level Control
48
JP25
On
Off
JP26
On
Off
Fig 12-7: RB-HD6 Master Level Control.
Channel Volume Controls
Each channel has its own volume control so that you have control of the signal volume to an
individual output whether it is from the master input or the override input.
Technical Specifications
Audio Specifications
Input Impedance:
Maximum Input Level:
Output Level:
Override Inputs:
Individual Volume Control:
Master Volume Control:
>20kΩ balanced bridging (main),
>10kΩ unbalanced (insert points)
+28dBu
Drives 150 mW into 32Ω to 600Ω headphones
+3dBu for full volume at +18dB gain
-60dB to +18dB gain
±10dB gain
Connections
Main Stereo Inputs:
Insert Inputs &
Parallel Outputs: Outputs:
Mains Input:
Fuse Rating:
2 x XLR 3 pin female (Balanced, can be wired unbalanced)
6 x ¼” (6.35mm) A-gauge 3-pole stereo jack sockets
(unbalanced, jumper configured)
6 x ¼” (6.35mm) A-gauge 3-pole stereo jack sockets
Filtered IEC, 110V-120V, or 220-240V switchable, fused, 9W maximum
Anti-surge fuse 100mA 20 x 5mm (230VAC)
Anti-surge fuse 250mA 20 x 5mm (115VAC)
Equipment Type
RB-HD6: 6 way stereo headphone distribution amplifier
Physical Specifications
Dimensions (Raw): Dimensions (Boxed): Weight:
48cm (W) x 10.8cm (D) x 4.2cm (H) (1U)
53cm (W) x 20.5cm (D) x 6cm (H)
Nett: 1.35kg Gross: 2.0kg
Redbox User Handbook No 2
AUDIO D ISTRIBUTION
AMP LIFIERS
13
13 RB-DHD6 Digital 6 Way Headphone Distribution Amplifier
Introduction
Fig 13-1: RB-DHD6 Front Panel.
Useful for connection to digital mixing desks, digital routers and matrices, the RB-DHD6
connects directly to an AES/EBU or S/PDIF output to provide the highest quality audio
directly to the headphones. The input connectors consist of a single balanced XLR-3 for the
AES/EBU input and a single unbalanced phono connector for the S/PDIF input.
A button located on the rear panel is used to select either the AES/EBU, or S/PDIF, input and
de-emphasis on the output can be controlled via dipswitch. If de-emphasis is selected, the
RB-DHD6 will decode 50/15µs emphasis when indicated by certain channel status bits in the
incoming digital audio data.
When operating, the front panel power LED flashes red and amber whenever the unit is not
synchronised to the incoming digital signal.
System Block Diagram
AES/EBU
Digital
Input
AES
Receiver
Audio
Output
Amp
DAC
S/PDIF
Fig 13-2: RB-DHD6 System Block Diagram.
Front Panel Indicators & Controls
Sync & Power LED
Volume
Controls
Volume
Control
Stereo Jack
X6
Output
AU D I O D I S T RIBUTION AM PLIFIER S - R B -D HD 6
The RB-DHD6 digital 6 way headphone distribution amplifier is a 1U rackmount which receives a digital input signal, as either AES/EBU or S/PDIF and
converts it to 6 individually buffered, jack-plug, headphone outputs, each with
their own volume control.
Headphone Outputs
Fig 13-3: RB-DHD6 Front Panel Controls.
Redbox User Handbook No 2
49
13
AU DI O DI S T R I B U T I O N
A M P LI F I E R S
Sync & Power Indicator
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
Flashing between red and amber – indicates a loss of a valid digital input signal.
AUD IO DISTRIB UTION AMP LIFIERS - RB - D H D 6
Headphone Outputs
The headphone outputs on the front panel consist of six ¼” stereo jack sockets, designed to
drive 150 mW into 32Ω to 600Ω professional headphones.
Volume Control
The headphone outputs each have their own volume control and have a maximum output
level of +12dBu.
Rear Panel Connections and Operation
Status
Select
Switches
Digital
Input
Select
AES/EBU S/PDIF
Input
Input
Fig 13-4: RB-DHD6 Rear Panel.
AES/EBU Input
The digital input XLR 3 pin socket has an impedance of 110Ω. It has the 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 Input
The S/PDIF digital phono input has an impedance of 75Ω.
Status Select Switches
Status
1
On
1
Off
2
3
4
De-emphasis On
De-emphasis Off
Reserved
Reserved
Reserved
Fig 13-5: RB-DHD6 Status Select Switches.
50
Redbox User Handbook No 2
HEADPHONE DISTRIBUTION
AMP LIFIERS
13
If de-emphasis is ‘on’ (switch 1) the RB-DHD6 will decode 50/15µs emphasis when indicated
by certain channel status bits in the incoming digital audio data. When ‘off’, no de-emphasis
is applied. The switch is ‘on’ when it is down.
Digital Input Select Button
This button is used to switch the digital input between the AES/EBU XLR connector (button
out) and the S/PDIF phono connector (button in).
Technical Specifications
110Ω ± 20% AES/EBU
75Ω ±5% S/PDIF
30kHz – 100kHz
>100dB
Drives 150 mW into 32Ω to 600Ω headphones
+12dBu
-80dBu to +12dBu
Connections
Digital Inputs:
Headphone Outputs:
Mains Input:
Fuse Rating:
1 x AES/EBU XLR 3 pin female
1 x S/PDIF RCA phono
6 x ¼” (6.35mm) A/B gauge 3-pole stereo jack sockets
Filtered IEC, 110-120V, or 220-240V switchable,
fused 10W max
Anti-surge fuse 100mA 20 x 5mm (230VAC)
Anti-surge fuse 250mA 20 x 5mm (115VAC)
Operational Controls
Digital Input Select:
De-emphasis:
AES/EBU or S/PDIF, via push-switch
DIP switch
Equipment Type
RB-DHD6 Digital 6 way stereo headphone distribution amplifier
Physical Specifications
Dimensions (Raw)
Dimensions (Boxed)
Weight
Redbox User Handbook No 2
48cm (W) x 10.8cm (D) x 4.2cm (H) (1U)
53cm (W) x 20.5cm (D) x 6cm (H)
Nett: 1.6kg
Gross: 2.2kg
AU D I O D I S T RIBUTION AM PLIFIER S - R B -D HD 6
Audio Specification
Input Impedance: Sample Freq. Range: Dynamic Range:
Headphones:
Max Output Level:
Headphone Gain Range:
51
14
CO N N E C TO RS & C A B LI NG
14 Connectors & Cabling
Many of the problems associated with installing and maintaining studio equipment are due
to the use of poor cables or faulty connections. It is recommended that, wherever possible,
pre-wired cables are purchased from recommended manufacturers. If you need bespoke
cables making, please ensure that a qualified engineer carries out the work.
The main types of connectors used with the Redboxes are the following:
CON N EC TORS & C A BLI N G
XLR 3 Pin Connectors
The following diagram shows the pin details for the 3 pin XLR sockets and plugs:
Male
Female
Pin 2
Phase Signal (Hot)
Pin 2
Phase Signal (Hot)
Pin 1
Screen Signal
Pin 1
Screen Signal
Pin 3
Non Phase Signal (Cold)
Pin 3
Non Phase Signal (Cold)
Fig 14-1: XLR Connectors.
RCA Phono Connectors
The following diagram shows the connection details for the RCA phono connectors:
Ground
Signal
Fig 14-2: RCA Phono Connector.
¼” Jack Connector
The following diagram shows the connection details for the jack connector:
¼” ‘A’ Gauge Stereo Jack Plug
(In Phase) Tip-Hot Signal
(Non Phase) Ring-Cold Signal
Sleeve-Ground (Screen) Signal
¼” ‘A’ Gauge Stereo Jack Plug
Used For Headphones
Tip-Left Signal
Ring-Right Signal
Sleeve-Ground (Screen) Signal
Fig 14-3: ¼” Jack Connector.
52
Redbox User Handbook No 2
CO NNE C TORS & C ABLING
14
D-Type Connectors
The following diagram shows the connection details for the D-type connectors as viewed
from the rear of a Redbox :
Pin 1
Male
Pin 14
Pin 13
Pin 13
Pin 25
Pin 25
Female
Pin 1
Pin 14
Fig 14-4: 25 Way D-Type Connectors.
Male
Pin 10
Pin 9
Pin 9
Pin 15
Pin 15
Female
Pin 1
Pin 10
Fig 14-5: 15 Way D-Type Connectors.
Pin 1
Male
Pin 6
Pin 5
Pin 5
Pin 9
Pin 9
Fig 14-6: 9 Way D-Type Connectors.
Redbox User Handbook No 2
Female
Pin 1
Pin 6
CON N E C TORS & C ABLIN G
Pin 1
53
15
G LO SS A RY
G LOS S A RY
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Glossary
1kHz
ADSL AES AES/EBU AM APT-X ATRAC Attenuation B-Channel Balance Balanced Audio CAR CAT 5 CD Cleanfeed Clipping CMRR CODEC Codecs Cross-talk DA DAB 1000Hz or 1 kilohertz tone of 1kHz is often used for line-up and testing.
Asynchronous Digital Subscriber Link - a broadband delivery system over
standard telephone lines (between the exchange and the user).
Audio Engineering Society.
Professional digital audio standard covering frame format, connections
and interfaces. Interface is usually on XLR sockets and plugs.
Amplitude Modulation - older analogue modulation standard used on
long, medium and short wave.
Data reduction process for reducing the amount ofstorage or bit-rate
need for audio.
Adaptive Transform Acoustic Coding - the data reduction of compression
scheme used in Mini-disk machines.
The reduction of a signal level. Attenuation is usually measured in dB.
Bearer Channel - the main carrier channels used in ISDN.
The relative levels of the left and right channels of a stereo signal.
A way of sending audio over cable that protects it from induced
interference.
See racks room.
Category 5 - type of cabling/connectivity standards used in
computer networking.
Compact Disc.
A cleanfeed is a signal produced by a telco module on a mixer which is
used as the output to be fed back to a caller on a telephone line.
The cleanfeed is a sum of all the other signals which constitute the
programme output, except for the caller’s audio. A cleanfeed signal will
generally be of a better quality than a mix-minus signal.
The onset of severe distortion in the signal path, usually caused by the
peak signal voltage being limited.
Common Mode Rejection Ratio. This is the ratio of the extent to which a
differential amplifier will cancel noise, which is present on both inputs,
compared to its ability to amplify the signal.
COder-DECoder - used to change a signal from one format to another
and back again.
Using digital circuits being offered by telecom providers, usually ISDN
(Integrated Services Data Networks) or other data transfer methods,
audio can be transferred with good to excellent quality over what almost
amount to dial-up telephone lines. The units operate by Coding the
audio into a digital data stream that can be transferred over the digital
circuit which is Decoded at the receiving end (Thus CoDec).
By using single or multiple circuits, very high quality audio can be
transferred from one place to another, even internationally.
This is the amount of a signal from a bus which appears, or is induced,
on a different signal. The problem is usually most prevalent with
adjacent channels.
Distribution Amplifier.
Digital Audio Broadcasting = now called Digital Radio.
Redbox User Handbook No 2
GLOSSARY
Digital Audio Tape.
A ratio of two voltages or signal levels, expressed by the equation
dB=20LOG(V1/V2)
Adding the suffix “u” denotes that the signal is relative to 0.775V RMS.
Adding the suffix “v” denotes that the signal is relative to 1V RMS.
This is radio code signal sourced from Mainflingen, near Frankfurt in
Germany, which can be used to automatically synchronize the
Sentinel+ audio logger and PC time to an accurate atomic clock,
European Time.
DDS and DDS-2 are world-wide standards established by Sony and
Hewlett-Packard which introduce many levels of error checking as data
is written to a DAT tape. DDS(-2) drives and tapes are used in security
products all over the world. 120m DDS-2 DAT tapes are more accurate
and reliable than DDS tapes and are able to store twice as much
audio data.
Direct Inject - a means of driving audio, usually from an instrument such
as a guitar, to allow the audio signal to be fed directly into a sound
desk input.
Dynamic Label segment - a text message scheme used in digital radio,
usually to carry information about the programme. Like the radio-text
scheme used in RDS.
Digital Signal Processing.
European Broadcasting Union.
Equivalent input noise. It is the ratio of output noise to the gain. It
describes the level of noise which would need to be fed into an ideal
amplifier to produce the measured output noise.
(Electronic news gathering). Machines that can record audio and
video information digitally.
(RDS) Enhance Other Networks - a scheme for switching a listener’s radio
to another Effective Radiated Power.
(Equalisation). This is a method of cutting or boosting selected bands of
frequencies in a signal.
Frequency Modulation - a way of sending audio or data over a radio
carrier, the 88 - 108 Broadcast Band is often known as the FM Band.
Full Scale Digits - This is the analogue representation of the maximum digital value that the converter in question can see before digital
clipping occurs.
Third generation mobile telephone system that may allow broadband
transmission of Global Positioning System.
The degree of amplification, or attenuation, applied to a signal.
Gramophone Reproducer - a turntable with a ‘pick-up’ amplifier and
remote start interface.
High Speed Data Link.
See TBU
International Elecrotechnical Commision - often used to refer to a mains
connectivity standard, i.e. A type of plug/socket similar to that of a kettle,
used on most pro-audio equipment.
Integrated Services Digital Network - a system for sending high bandwidth
material over standard telephone lines.
Redbox User Handbook No 2
G LOS S A RY
DAT dB (decibel) DCF DDS & DDS-2
DI DLS DSP EBU EIN ENG EON EQ FM FSD
3G Gain GRAM HDLC Hybrid IEC ISDN 15
55
G LOS S A RY
G LO SS A RY
56
kbps kHz LAN LCD LED LNB MCR MDU MF MHz Mix-minus Mono MP3 MPEG MSF Musicam MUX Pan PFL PI Code PPM Promo PS Name (RDS) PSU PTY Kilo-bits per second - the number of 1s or 0s transmitted or transferred in
one second.
Kilo Hertz (samples per second).
Local Area Network - scheme where several computers on the same
premises are connected together so that they can exchange data.
Liquid Crystal Display (grey displays e.g. on calculators).
Light Emitting Diode (small lights e.g. on computers).
Low Noise Block - the RF amplifier attached to a satellite dish.
See racks room.
Mains Distribution Unit - a panel of mains outlets for power distribution.
Medium Frequency - another name for Medium Wave - roughly
frequencies between 300kHz and 3MHz.
Mega-hertz - One million cycles per second.
A mix-minus is similar to a cleanfeed except that the caller’s voice is
removed from the signal electronically. Due to phasing problems at the
signal band edges, the mix-minus method often produces a lower
grade signal.
Monophonic sound (system of broadcasting, recording or reproducing
sound) using only one channel between source and loudspeaker.
MPEG 1 Layer 3 - see MPEG.
(ISO MPEG) Motion Picture Experts Group. For audio, this is used to refer
to a framing format standard. There are several layers and variants. Most
common ones are listed below.
MPEG 1 Layer 1 Used for Digital Compact Cassette.
MPEG 1 Layer 2 (Musicam) used in digital radio, digital terrestrial
television, ISDN and many hard-disk storage systems.
MPEG 1 Layer 3 Known as MP3. A more elaborate version of
MPEG 1 Layer 2 that allows for audio storage using low bit-rates.
This is radio code signal sourced from Rugby in England, which can be
used to automatically synchronize the Sentinel+ audio logger and PC
time to an accurate atomic clock, UK Time.
Masking Pattern Universal Sub-Band Encoding.
Short for Multiplex - a ‘package’ of digital radio services.
This controls the levels sent to the left and right outputs and is an
abbreviation of ‘panorama’.
(Pre Fade Listen, or Cue). This is a method of auditioning audio material
independently of the programme output, without routing the signal
to air. The PFL button on each channel routes the signal to the PFL bus,
where it can be monitored.
(RDS) Programme Information Code used to identify an FM RDS station.
Peak Performance Meter (BBC Specification).
Something used to promote a product.
Programme Service Name - 8 characters used for naming an
FM RDS station.
Power Supply Unit.
(RDS and DAB) Programme Type. A code transmitted to describe the
overall programme content of a radio station (Static PTY) and/or the moment by moment content (Dynamic PTY). RDS has 32 codes although
3 are used in special circumstances only.
Redbox User Handbook No 2
GLOSSARY
Often called the Master Control Room (MCR) or Central Apparatus Room
(CAR), the racks room is an engineering area containing studio routing
to transmitter equipment. Outside sources, phone-in equipment, off-air
and transmitter status monitoring and logging equipment (or the
transmitter itself !) are stored here with limited access.
Radio Data System.
An echo (in very basic terms).
Radio Frequency.
A connection standard used in computer networking.
Sony/Phillips Digital Interface. Domestic digital audio interface standard
using phono connectors or optically using fibre-optic connectors.
Sound Pressure Level.
Traffic Announcement (flag) - a means of signalling to a radio with FM
RDS indicating that traffic/travel news is being broadcast.
Talk-back (and reverse talk-back). This is the ability for two or more
studios to communicate with each other off-air.
See Telephone Balance Unit
Transmission Control Protocol / Internet Protocol. Computer
interconnection methodology used on the internet and LANs.
Telephone hybrids provide the interface between professional audio
equipment and the public telephone network. They provide protection
for your equipment and the public telephone lines, allowing for varying
line signals and line conditions. Automatically cancelling out the
unwanted signal they also facilitate two-way communication down a single telephone line. In most European countries, including the UK, the TBU must be approved for connection to telephone company lines. Sonifex TBU’s carry British Telecom and pan European approval.
The Total Harmonic Distortion is the percentage presence of signals
outside the measured reference frequency.
(RDS) Traffic Message Channel.
Traffic Programme (flag) - a means of indicating to an RDS radio that a
station will carry traffic announcements.
A height measurement for rack-mount equipment:
1U = 1.75 inches
2U = 3.5 inches
3U = 5.25 inches
4U = 7 inches
Uninterruptible Power Supply. A device which maintains power to
equipment when the electricity supply fails.
Very High Frequency - frequencies between 30MHz and 300MHz.
Vertical Polarisation i.e. of FM radio transmission.
Voltage Standing Wave Radio
Voltage units
Wireless Application Protocol - a system for delivering mini-web pages to
mobile phones from the Internet.
A data communications protocol used in synchronous connections.
Professional, robust lockable audio connector - sometimes known as a
‘Cannon’ after one of the earlier manufacturers.
Redbox User Handbook No 2
G LOS S A RY
Racks Room RDS Reverb
RF RJ-45 S/PDIF SPL TA T/B TBU
TCP/IP Telephone Balance
Unit (TBU)
or Hybrid
THD
TMC TP
U
UPS VHF VP VSWR VU WAP X21 XLR 57
w w w. s o n i fe x . c o. u k
t:+44 (0)1933 650 700
f:+44 (0)1933 650 726
s a l e s @ s o n i fe x . co. u k
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