Sonifex HY02 DIGITAL, User Handbook Manual

Introduction & Installation       Page 1-1 

HY02 Digital TBU User's Guide 

1.  Introduction & Installation 

1.1. Introduction 

The HY02 

Digital

 telephone hybrid is a series of equipment presented as either a 

single channel unit or a twin channel unit mounted within a 1U high 19” rack frame. 

DHY 02S

Single automatic TBU, rack mounted with PSU. 

DHY 02SR

Single automatic TBU, with ringing detector, rack mounted with PSU. 

DHY 02T

Twin automatic TBU, rack mounted with PSU. 

DHY 02TR

Twin automatic TBU, with ringing detector, rack mounted with PSU. 
 

DHY 02EC

Eurocard version, without ringing detector. 
 
This handbook covers the first four pieces of equipment in the above list. In each 

case the power supply is separately encased within the rack and is connected to the telephone hybrid 
processor by means of short link cables. The twin channel unit incorporates two separate power 
supplies within the same enclosed chassis. For the DHY 02S and DHY 02T units, please ignore the 
section of this handbook which deals with ringing detector, which is not installed in these units.  To 
find out if you have the ringing detector version of the equipment, please check the Serial Number on 
the rear panel. If the Serial No. is of the format DHYR#### ( instead of DHY#### ), then the unit is 
installed with the ringing detector. 

1.2. Description 

 
The telephone hybrid is a two wire to four wire converter which provides the 

interface between a caller on the telephone line and the input to the mixing desk. Built to a very high 
specification, it is simple to install and automatically adapts to line conditions and programme content. 
Analogue signal limiting, controlled from the DSP, is used in the send and receive paths to ensure that 
signal break-up and severe overload problems do not occur. 

The unit has independent LED bar graph metering of send and receive levels with 

input and output gain controls provided at the front panel. Both the input and the output are 
transformer balanced providing complete isolation. 

The illuminating line connect control has a remote facility and the equipment is fitted 

with K-break and dial tone disconnect as standard. Audio connectors are the standard XLR-3 type. 

By using a high power DSP and a high quality 16 bit dual codec, the HY02 

Digital

gives some of the best audio figures available - it provides full adaptive echo cancellation to 28msec 
and gives unwanted sideband rejection figures of 69dBu on tone, reference peak output of +8dB. The 
HY02 

Digital

 has been designed to achieve the best possible audio performance from a telephone line. 

The unit ensures that the dynamic range is as large and the distortion and noise are as small as possible. 

The following product description is necessary for BABT approval and provides 

information on the connection and operating conditions of the units.