Sonifex DHY-04 User manual

Manufacturers of audio & video
products for radio & TV broadcasters
HANDBOOK
DHY-04 Digital TBU
DHY-04
DHY-04S
DHY-04T
Single Freestanding Automatic Digital TBU, AES/EBU &
Analogue I/O With Ethernet
Single Rackmount Automatic Digital TBU, AES/EBU &
Analogue I/O With Ethernet
Twin Rackmount Automatic Digital TBU, AES/EBU &
Analogue I/O With Ethernet

DHY-04 Handbook
Made in the UK by
This handbook is for use with the following product:
DHY-04 Single Freestanding Automatic Digital TBU, AES/EBU & Analogue I/O With Ethernet
DHY-04S Single Rackmount Automatic Digital TBU, AES/EBU & Analogue I/O With Ethernet
DHY-04T Twin Rackmount Automatic Digital TBU, AES/EBU & Analogue I/O With Ethernet
©Sonifex Ltd, 2017
All Rights Reserved
Revision 1.05, November 2017
Sonifex Ltd, 61, Station Road, Irthlingborough,
Northants, NN9 5QE, England.
Tel: [phone]
Fax: [phone]
Email: [email protected]o.uk
Website: 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 the vendor. Sonifex Ltd shall not be liable for any loss or damage
whatsoever arising from the use of information or any error contained in this manual.
No part of this manual may be reproduced or transmitted in any form or by any means, electronic
or mechanical, including photocopying, recording, information storage and retrieval systems, for any
purpose other than the purchaser’s personal use, without the express written permission of Sonifex
Ltd. Unless otherwise noted, all names of companies, products and persons contained herein are part
of a completely fictitious adaptation and are designed solely to document the use of Sonifex product.
For the latest Sonifex handbook information please visit the
Sonifex website at www.sonifex.co.uk

Contents
Contents
Product Warranty - 2 Year Extended i
Sonifex Warranty & Liability Terms & Conditions i
1. Definitions i
2. Warranty i
Unpacking Your Product ii
Repairs & Returns iii
Conformity iii
Conformity iii
ACMA Conformity iii
Safety & Installation of Mains Operated Equipment iii
Voltage Setting Checks iii
Fuse Rating iii
Power Cable & Connection iii
WEEE Directive iv
Atmosphere/Environment iv
1 What Is A Telephone Hybrid? 1
The Best Telephone Hybrid in the World Just
Got Better! 1
DHY-04 Single Freestanding Automatic Digital TBU 2
Available Formats 3
DHY-04S Single Rackmount Automatic Digital TBU 3
DHY-04T Twin Rackmount Automatic Digital TBU 3
2 Configuration & Controls - DHY-04, DHY-04S, DHY-04T 4
Front Panel Controls 4
Power LED Indicator 4
Reset Button 4
Speed Dial Buttons 4
AES/EBU Lock LED 4
Line Hold/Connect Button 4
Gain Switches (Level To & From The Line) 5
LED Bargraphs 5
Status & Operating Mode Information 5
DHY-04 Internal Controls & Adjustments 5
Jumper and Select Switcher Functions 5
Rear Panel Controls & Connections 6
AES/EBU & Analogue Combined Line Output 6
Mic/Line & AES/EBU Input 6
Mic/Line Input Select Switch 6
Adjusting the Microphone Gain Level 6
Remotes 6
Conference Audio/Record Output 6
Telephone Handset 7
Telephone Line 7
RJ11 Telephone Connections 7
RS232 Serial Port 7
Ethernet Port 8
Mains Input 8
Protective Earth Terminal 8
Configuration Settings DIPSwitches 8
Country Code Selection 9
IEC Mains 13
Telephone Line 13
Handset 13
Remote Line Hold 13
Mic/Line Input 13
XLR Output 13
Using The AES/EBU Input & Output 14
Using the DHY-04 14
Call Established 15
Using the Conference Port as a Record Output 16
Using the Conference Port to Share a Stereo Digital Audio
Connection Between Two DHY-04 Units 16
4 Hybrid Technical Description 17
Electrical Interface 17
Impedance Matching 17
Echo Cancellation 17
5 Serial Port Control 19
DHY-04 Serial Connection 19
SCI Software 19
Serial Interface Commands & Responses 19
Error Messages 19
6 Webserver & Network Discovery 20
Connecting to the Device 20
First Time Usage 20
MDNS-SD and Bonjour 20
Sonifex Service Discovery App 20
Home Page 22
Status 22
Line 22

Contents
Dial 22
Dialler Page 23
Call State 23
Dial 23
Configuration - Telephone 24
Country Code 24
Disconnect Settings 24
Answer Control 24
Buttons 25
Configuration - Telephone Details 25
Configuration-Remote 26
Input Port 26
Output Port 27
Configuration-Misc 28
Config Name 28
Description 28
Echo Duration 28
Conference Port Function 28
Force Analogue Output 29
Save Cancellation Coeffs 29
Password Setting 30
Network Settings 31
Bonjour Name 31
Static IP Address 31
Static Subnet Mask 32
Gateway IP Address 32
Dynamic Addressing 32
Device Info Page 33
Update Firmware Page 34
Update Firmware 34
Update Config Files 35
Log In 36
Bootstrap Mode 37
7 Technical Specification 38
Approvals Information 40
Manufacturer 40
Equipment Type 40
Approval File Reference 40
Functions 40
Specified Systems 41
Ringer Equivalence Number 41
Accessory Ports 41
Conditions 41
Series Connection 41
Facilities 41
Statutory Mark 41
Appendix 1 - Telephone Registers 42
AC Impedance Setting 43

Figures
Figures
Figure 1-1: DHY-04 Front & Rear. 2
Figure 1-2: DHY-04S Front & Rear. 3
Figure 1-3: DHY-04T Front & Rear. 3
Figure 2-1: Front Panel Controls. 4
Figure 2-2: Internal Position of Jumper J1. 5
Figure 2-3: Rear Panel Controls. 7
Figure 2-4: Configuration Settings Switches. 8
Table 2-1: Supported Disconnect Tone Details by Country. 12
Figure 3-1: DHY-04 User Connections. 13
Figure 3-2: Conference Port Cable Connections. 16
Figure 6-1: Bonjour Service Discovery Page. 21
Figure 6-2: Legacy Service Discovery Page. 21
Figure 6-3: Home Page – for basic call control and
setting preset calls. 22
Figure 6-4: Dialler Page. 23
Figure 6-5: Telephone Configuration. 24
Figure 6-6: Detailed Telephone Configuration. 25
Figure 6-7: Remote Port Configuration. 26
Figure 6-8: Misc Configuration. 28
Figure 6-9: Password Setting Page. 30
Figure 6-10: Network Page. 31
Figure 6-11: Device Info Page. 33
Figure 6-12: Updates Page. 34
Figure 6-13: Log In Page. 36
Figure 6-14: Bootstrap Page. 37
Table 8-1: Telephone Interface Register 16. 42
Table 8-2: Telephone Interface Register 17. 42
Table 8-3: Telephone Interface Register 18. 42
Table 8-4: Telephone Interface Register 22. 42
Table 8-5: Telephone Interface Register 23.
(Use sum of required values). 42
Table 8-6: Telephone Interface Register 23 - RTO Values. 42
Table 8-7: Telephone Interface Register 23 – RCC Values. 42
Table 8-8: Telephone Interface Register 24. 43
Table 8-9: Telephone Interface Register 26. 43
Table 8-10: Telephone Interface Register 30.
(Use sum of required values) 43
Table 8-11: Telephone Interface Register 30
- AC Impedance settings. 43
Table 8-12: Telephone Interface Register 31.
(Use sum of required values) 44
Table 8-13: Telephone Interface Register 59.
(Use sum of required values) 44

Warranty Registration
Sonifex Limited y61 Station Road yIrthlingborough yNorthamptonshire yNN9 5QE yUnited Kingdom
Tel: [phone] yFax: [phone] yEmail: [email protected] yInternet: www.sonifex.co.uk
Register Online for an
Extended 2 Year Warranty
As standard, Sonifex products are
supplied with a 1 year back to base
warranty.
If you register the product online, you
can increase your product warranty
to 2 years and we can also keep
you informed of any product design
improvements or modifications.
To register your product, please go online to www.sonifex.co.uk/register
Product:
Serial No:

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

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

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

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

1
What Is A Telephone Hybrid? 1
1 What Is A Telephone Hybrid?
Telephone hybrids, or telephone balance units (TBUs) 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.
Each telephone hybrid has a telephone line connection, a handset
connection and separate terminals for audio input and output from a
broadcast mixer, or other professional audio source.
A large proportion of Sonifex hybrids are used in radio and television
broadcasting applications for allowing external callers to be connected
to the studio mixing console. Most of the other units are supplied to
communication operations for allowing extremely effective conversion
between 4-wire audio circuits and standard telephone lines.
The Best Telephone Hybrid in the World Just
Got Better!
The DHY-04 telephone hybrid is an enhanced redesign of the DHY-03, the
best performing telephone hybrid in the world. It now has auto-sensing
combined analogue and AES/EBU inputs and outputs, front panel Speed
Dial buttons, together with an Ethernet interface to allow web browser
access to the configuration and internal settings. All whilst still retaining
stunning line balance rejection figures. For the best sounding audio calls
you’re likely to hear, you should specify the DHY-04.
Key new features of the unit include:
• Auto-sensing combined analogue or AES/EBU XLR input.
• AES/EBU sample rates up to 24 bit/96kHz accepted.
• Configurable analogue or AES/EBU XLR output.
• Ethernet port for remote configuration via web browser GUI.
• Remote dialling and line hold control via Ethernet.
• DTMF dial tone recognition for reporter remote access - a journalist can
dial into the unit which can recognise a pre-programmed DTMF numeric
code to automatically connect the journalist on-air.
• Four front panel speed-dial buttons for dialling 7 internally phone Speed
Dial numbers.
• Front panel Redial button for redialling the last number.
Product Function:
Provides separation between send and receive signals on an analogue
telephone network, provides professional level balanced input & output
signals and has echo cancellation.
Typical Applications:
Radio & TV station talk shows, telephony interface to the mixer.
Features:
• Fully automatic - adapts to varying line conditions and has automatic
signal limiting.
• Fully adaptive echo cancellation to 250msec - default is 24msec.
• 70dB typical line balance rejection offering superb performance and
crystal clear audio.
• Front panel input and output gain controls.
• Front panel LED metering of receive and send signals.
• Built-in conferencing for 2 hybrids, so that a single telco channel on a
mixing desk can receive 2 calls.
• Integrated ring detector - automatic call answering after a pre-
determined number of rings.
• Automatic call disconnection. Fitted with K-break, line polarity reversal
and dial tone disconnect detection, defined by the country selection.
• Automatic ducking facility allows the talent to ‘shout-down’, or talk over,
a caller by reducing the gain of the caller’s signal if it goes above a certain
level.

2
1 What Is A Telephone Hybrid?
• Local and remote line hold switching - calls can be remotely switched
through a mixing console.
• Line hold/release button to control line hold circuit, illuminates to
indicate the status of the line and flashes to show ring status.
• DTMF tone recognition allowing a opto-isolated GPI output to be made
on receipt of selected DTMF tones, e.g. for starting a studio automation
recorder automatically to record a remote telephone interview.
• International operation with built-in configurable settings for each
country.
• Country selection allows the unit to provide line impedance and a
simulation circuit to match the country.
• RS232 serial port for remote control of the TBU & DTMF tone dialling.
• Remote port distributes the remote line connect switch and tally output,
a momentary/latch selector and the DTMF detect output.
• The remote line connect switch can be either momentary or latching in
its action.
• Balanced mic/line input - 10k balanced input selectable for 0dBu clean
feed line, or microphone level with adjustable gain.
Figure 1-1: DHY-04 Front & Rear.
DHY-04 Single Freestanding Automatic Digital TBU

3
What Is A Telephone Hybrid? 1
• Balanced output - 0dBu low impedance balanced output, with output
gain settings.
• Record output - the conferencing output can be set to give an output to
record just the caller or a mix of the caller and mic/line input signals for
recording both sides of the telephone conversation.
• Line limiter, bandpass filter and output noise gate with preset threshold
providing low distortion audio.
• Built in universal power supply between 90V AC and 250V AC, 47-63Hz,
IEC mains input.
• ETSI approval compliant with European PTT specifications.
Available Formats
The DHY-04 digital telephone hybrids are available in three different
DHY-04 Single automatic digital telephone hybrid, free standing
DHY-04S Single automatic digital telephone hybrid, rackmount
DHY-04T Twin automatic digital telephone hybrid, rackmount
DHY-04S Single Rackmount Automatic Digital TBU
Figure 1-2: DHY-04S Front & Rear.
DHY-04T Twin Rackmount Automatic Digital TBU
Figure 1-3: DHY-04T Front & Rear.

2 Configuration & Controls - DHY-04, DHY-04S, DHY-04T
4
2 Configuration & Controls -
DHY-04, DHY-04S, DHY-04T
Front Panel Controls
Power LED Indicator
The power LED indicates that the equipment is powered and operational
when illuminated.
Reset Button
In the unlikely event that the DHY-04 unit fails to respond, press the reset
button to reboot the unit.
In extremis (especially valuable when the network settings have been
incorrectly entered) the unit can clear the settings to factory default by
pressing the reset three times in succession as follows – press reset; wait
for 7 seconds; press reset again; wait for 7 seconds; press reset again and
the unit will clear all the current settings and return to the factory defaults.
Speed Dial Buttons
Press the appropriate button to call Speed Dial settings 1-4. Press and hold
buttons 1-3 to call Speed Dial numbers 5-7 or press and hold Speed Dial 4
to redial the last number. The numbers are configured using the embedded
webserver.
AES/EBU Lock LED
This is a red/green LED with green indicating a successful lock to the
incoming AES/EBU signal, i.e. a valid AES signal is present. The LED is red for
a non-valid AES/EBU input.
Line Hold/Connect Button
This is the front panel button used to connect calls to, and disconnect calls
from, the telephone line. The line connect button flashes when an incoming
call is detected and illuminates to indicate the call has been connected.
Operation of this button can be remotely controlled by GPI.
Figure 2-1: Front Panel Controls.
Line Hold/Connect
Button
Speed Dial
Buttons
Power
LED Indicator
Reset Button
AES Lock
LED
Gain Switches
Level Adjustment
LED
Bargraphs

5
Configuration & Controls - DHY-04, DHY-04S, DHY-04T 2
Gain Switches (Level To & From The Line)
These switches allow gain/attenuation to be applied to the incoming &
outgoing analogue audio. Each switch has 3 positions. Rotating the switches
clockwise give gains of -6dB, 0dB & +6dB. The normal position for the
transmit gain to the telephone line (lower switch) is 0db and for the receive
gain from telephone line (upper switch) is –6dB.
LED Bargraphs
These 8 position bargraphs, by default, indicate the signal levels of the
incoming XLR audio signal from the mixer (lower) and outgoing XLR audio
to the mixer (upper). For best operation set the signal gain switches to
achieve all 3 yellow LEDs mostly illuminated with occasional audio peaks
lighting the first red LED.
The scale indicates from left to right: Green (-30dB, -18dB, -6dB); Yellow
(-3dB, 0dB, +3dB); & Red (+6dB, +9db).
Status & Operating Mode Information
The LED display is also used to indicate special operating modes and other
settings as follows:
• Alternating 2 LEDs on, 2 LEDs off pattern indicates that the DHY-04 is
checking the status of the Line Connect Button to test the Bootstrap
Mode (see page 36)
• Alternating 4 LEDs on, 4 LEDs off pattern indicates that the DHY-04 has
entered Bootstrap mode, because either the Line Hold/Connect Button
was held down for approximately 10 seconds at power up, or the main
code has been corrupted (most likely due to a previous incomplete
firmware update).
• Alternating 8 LEDs on, 8 LEDs off pattern indicates that the DHY-04 has
received an update command from the web page and is updating the
firmware (valid in either Bootstrap or Normal operation).
• On normal power up, the top row of LEDs shows the current country
selection (see table 2-1) with LEDs numbered from left to right reflecting
the DIPSwitch settings.
DHY-04 Internal Controls & Adjustments
If you need to get inside the unit to make configuration adjustments, simply
remove the 4 screws in the corners of the rear panel. The rear panel and
main PCB will slide backwards out of the metal chassis.
When re-inserting the main PCB, ensure that the PCB edges are in the
runners inside the chassis and also that the power LED and line connect
button are in the correct place in the front panel.
Warning: The power must be switched off at the supply or the power lead
must be disconnected before attempting to open the unit. Removal of the
cover can expose dangerous voltages.
Warning: The telephone line plug should be disconnected from the
telecommunications network exchange line before removing the cover.
Jumper and Select Switcher Functions
Put a 2 pin jumper over J1 to switch in an extra 10dB of audio input gain to
allow for use of domestic level mixing desks.
Figure 2-2: Internal Position of Jumper J1.

2 Configuration & Controls - DHY-04, DHY-04S, DHY-04T
6
Rear Panel Controls & Connections
AES/EBU & Analogue Combined Line Output
The line output is an XLR 3 pin male connector with the following
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analogue or AES/EBU audio by following the input, i.e. a digital input
produces a digital output.
Pin 1: Screen
Pin 2: Phase
Pin 3: Non-Phase
Mic/Line & AES/EBU Input
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floating). It is autosensing for either analogue balanced or AES/EBU (left
channel) signals.
Pin 1: Screen
Pin 2: Phase
Pin 3: Non-Phase
Mic/Line Input Select Switch
This push-button switch sets the input signal mode:
Switch depressed (in) - Mic input mode selected
Switch not depressed (out) - Line input mode selected
Adjusting the Microphone Gain Level
The Mic Level preset potentiometer controls the level of the input signal
when the Mic/Line Input Select Switch is set to Mic input. The input signal
level in Line mode is factory set and is not affected by this control. The Mic
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with a maximum gain of 70dB. Use a jeweller’s screwdriver to adjust the
gain between 70dB and 52dB. The gain range can be extended by ±6dB by
using the front panel ‘Level to The Line’ switch.
Remotes
The remote port allows you to control the line hold circuit from a mixing
desk or other remote device and also outputs opto-isolated outputs to
indicate the line hold status and the DTMF detect function.
The remote connector is a 9-way female (socket) ‘D’ type. To remotely
control the line connect, connect pin 1 to pin 2. The action of this remote
can act as momentary or latching by pin 6 having no connection or
connecting to 0V respectively.
Pins 3 & 7 is an opto-isolated remote line connect indicator and pins 5 & 7
is an opto-isolated DTMF detect output. They can use the local supply pins
4 & 8 to drive an LED indicator or a low current load.
Pin 1: Remote Line Connect Switch
Pin 2: Common – 0V
Pin 3: Opto-Isolated Line Connect Indicator - NPN Emitter
Pin 4: Common – 0V
Pin 5: Opto-Isolated User GPO (DTMF Detect*) Indicator - NPN Emitter
Pin 6: User GPI (Momentary/Latch Line Connect Switch - connect to
0V for latching action*)
Pin 7: Opto-Isolated Line Connect Indicator - NPN Collector
Pin 8: 5V out (current limited supply for pins 7 & 9)
Pin 9: Opto-Isolated User GPO Indicator - NPN Collector
The remote line connect indicator mimics the front panel Line Hold/
Connect Switch lamp, i.e. it flashes when ringing and is on when the line is
held.
User GPO and GPI have their default functions (*) set to the same use as
the DHY-03.
Conference Audio/Record Output
This is an RJ45 analogue audio connector to cross connect to another
DHY-04. This will allow a single TBU channel on a mixing desk to handle 2
calls, one to each DHY-04. Alternatively the conference output signals can
Pin2
Phase Signal
Pin 1
Screen Signal
Pin 3
Non-Phase Signal
Pin2
Phase Signal
Pin 1
Screen Signal
Pin 3
Non-Phase Signal

7
Configuration & Controls - DHY-04, DHY-04S, DHY-04T 2
be used as a record output by using the webserver interface. The output
is then a sum of the caller and main audio input so both sides of the
conversation can be recorded from this output.
Pin 1: N/C
Pin 2: N/C
Pin 3: Conference Input (phase)
Pin 4: Conference or Record Output (phase)
Pin 5: Conference or Record Output (non-phase)
Pin 6: Conference Input (non-phase)
Pin 7: N/C
Pin 8: N/C
Telephone Handset
This is the connection for a telephone handset and is an RJ11 6/4 socket.
There is a converter lead supplied with the DHY-04 for accepting a standard
UK BT605A telephone plug.
The connection details are the same as for the Telephone Line connector.
Telephone Line
This is the telephone line connection and is an RJ11 6/4 socket. Two cables
are supplied with the unit, to connect this either to a UK BT line jack socket,
or an RJ11 socket. The telephone line is connected via Pins 3 and 4 on the
RJ11 and Pins 2 and 5 on the BT Plug (the latch adjacent to Pin 6).
RJ11 Telephone Connections
Pin 1: N/C Pin 4: Telephone line B
Pin 2: Earth recall Pin 5: Ringer
Pin 3: Telephone line A Pin 6: N/C
Note: When not used in the UK, connect pins 3 and 4 only for operation.
RS232 Serial Port
The serial port allows direct connection to a 9 way ‘D’ type connector on a
PC via a pin to pin cable. See chapter 5 for details about this interface.
Pin 1: N/C Pin 6: N/C
Pin 2: TxD Pin 7: CTS
Mic Level Mic/Line Input
Select Switch
Configuration
Settings Switches
Figure 2-3: Rear Panel Controls.
AES/EBU & Analogue
Output
Mic/Line/AES/EBU
Input
Conference
Audio
Remotes
Connector
Telephone
Handset
Telephone
Line
Serial RS232
Port
Ethernet
Port
Mains IEC
Inlet
Earth Bond
Point

2 Configuration & Controls - DHY-04, DHY-04S, DHY-04T
8
Pin 3: RxD Pin 8: RTS
Pin 4: N/C Pin 9: N/C
Pin 5: Ground
Ethernet Port
This is an RJ45 port which should be connected via CAT5 cable to an
Ethernet device or switch. The port will automatically set the pins to suit
(Auto-MDX) and select the maximum available speed (10Mbps, 100Mbps or
1Gbps) depending on the connected infrastructure (Auto-Negotiation).
Mains Input
The power supply is connected via a filtered IEC Plug and is continuously
rated 85-264V AC @ 47-63Hz.
Protective Earth Terminal
This earth bond screw terminal is a screen terminal that must be connected
to an earth point.
Configuration Settings DIPSwitches
The SETTINGS switches are used to configure the DHY-04 in the modes
that you want it to operate. A label on the top panel of the unit shows the
orientation of the switches:
The following paragraphs describe the function of each switch; the default
or normal position is shown in curly brackets.
Noise Gate Select - SW1 {ON}
An output noise gate operates when the telephone signal is below the noise
gate threshold control. This noise gate reduces the output gain by 34dB
during low level signal conditions. This eliminates the effects of telephone
line cross talk. The noise gate can be switched off if you don’t wish to use it
by switching SW1 to the OFF position.
Ducking Enable - SW2 {ON}
This switch allows the received signal to be automatically attenuated by
18db when both received and sent audio are present in the hybrid. This
allows an operator in the studio to talk over the caller at all times.
Auto Disconnect Enable - SW3 {ON}
When SW3 is enabled (ON) the DHY-04 automatically disconnects from the
telephone line by detecting the appropriate disconnect regime selected for
the specific country according to the selected country code (see Table 2-2).
Line reversal and K-break work by changing the voltage on the line and
have parameters settings which indicate a duration range for which this
voltage change must be present. Tone detection has a more complicated
and extensive parameter set. A variety of single or dual tones with level
control are available together with the ability to handle cadence patterns,
where known countries disconnect requirements are preset, but if not the
ETSI default of 400Hz tone is used. These parameters can be defined to use
standard tones or the ‘User’ sets which are set via the webserver. You may
need this capability if your telephone system provides non-standard call
progress tones.
Country Set on
Power Up
Noise Gate Select
Force Static
IP Address
1 2 3 4 5 6 7 8
ON
OFF
Network
Cancellation Enable
Auto Answer Enable
Auto
Disconnect Enable
Ducking Enable
Unused
Figure 2-4: Configuration Settings Switches.

9
Configuration & Controls - DHY-04, DHY-04S, DHY-04T 2
Ring Detector (Auto Answer) Enable - SW4 {ON}
This switch enables the integrated ring detector, which automatically
answers incoming calls after the number of rings set using the webserver
(see page 24, Configuration - Telephone). The default is 2 rings.
Note double cadence ring tones count both rings in the cadence pattern.
Force Static IP Address – SW6 (ON)
When SW6 is enabled (ON) during the unit power-up routines, the Network
settings are overridden to force the unit to use a static IP address of
192.168.0.100 with a subnet mask of 255.255.255.0
Network Cancellation Enable – SW7 {ON}
When switch SW7 is enabled (ON) the DHY-04 performs the echo
cancellation routine on the incoming signal from the telephone line. This
would be the normal operational setting, but it may be disabled for special
circumstances.
Country Set on Power Up – SW8 {OFF}
SW8 is only read on power-up and needs to be ON to set the specific
country code to be used for the unit (set ON the remaining switches to
define the country code - see Table 2-1 on page 10). After power up,
the switches should be returned to their normal position, otherwise the
unit may fail to work correctly. The country code can also be changed via
the Ethernet port webserver, but in either case when the country setting
is altered, any calibration parameters are discarded as they will most likely
now be incorrect. These parameters include tuned hybrid impedance
settings & coefficients and default cancellation calculation coefficients.
Country Code Selection
The correct country code selection is essential for proper operation of the
DHY-04 unit. It ensures that all telephone approval parameters are met
for operation of this unit in various parts of the world. The table following
is likely to change with additional countries or PABXs and possible detail
changes for existing countries. However the actual country codes are fixed
and will not alter. For the latest table please refer to our website www.
sonifex.co.uk/dhy04
The country codes are selected on power up, by setting DIPSwitch 8 of the
SETTINGS on the rear panel to the “ON” position and setting DIPSwitches
1-7 as per the following table or from the Webpage. Once the system has
initialised – indicated by the chase pattern of LEDs on the lower bargraph,
then all switches should be returned to their previous position for the
correct operation of the unit. ETSI, the European Telecommunications
Standards Institute (http://www.etsi.org/) govern the telcoms standards
used and in the majority of cases, it has been provisionally assumed that
the disconnect tones are at the ETSI standard - Code 1 in the following
table.

2 Configuration & Controls - DHY-04, DHY-04S, DHY-04T
10
Country Code Tone Disconnect Type Frequencies Disconnect Details DIPSwitch Set On Power Up
ETSI – TBR21 1 400Hz Continuous 1
Argentina 2 400Hz * Continuous 2
Australia 3 400Hz * Continuous 1+2
Austria 4 400Hz * Continuous 3
Bahrain 5 400Hz * Continuous 1+3
Belgium 6 400Hz * Continuous 2+3
Brazil 7 400Hz * Continuous 1+2+3
Bulgaria 8 400Hz * Continuous 4
Canada 9 400Hz * Continuous 1+4
Chile 10 400Hz * Continuous 2+4
China 11 400Hz * Continuous 1+2+4
Colombia 12 400Hz * Continuous 3+4
Croatia 13 400Hz * Continuous 1+3+4
Cyprus 14 400Hz * Continuous 2+3+4
Czech Republic 15 400Hz * Continuous 1+2+3+4
Denmark 16 400Hz * Continuous 5
Ecuador 17 400Hz * Continuous 1+5
Egypt 18 400Hz * Continuous 2+5
El Salvador 19 400Hz * Continuous 1+2+5
Finland 20 400Hz * Continuous 3+5
France 21 400Hz * Continuous 1+3+5
Germany 22 400Hz * Continuous 2+3+5
Greece 23 400Hz * Continuous 1+2+3+5
Guam 24 400Hz * Continuous 4+5
Hong Kong 25 400Hz * Continuous 1+4+5
Hungary 26 400Hz * Continuous 2+4+5
Iceland 27 400Hz * Continuous 1+2+4+5
India 28 400Hz * Continuous 3+4+5
Indonesia 29 400Hz * Continuous 1+3+4+5
Ireland 30 400Hz * Continuous 2+3+4+5
Israel 31 400Hz * Continuous 1+2+3+4+5
Italy 32 400Hz * Continuous 6
Japan 33 Line Reversal 1+6