D&R Telephone Hybrid-2, User Manual

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Manual page 3
D&R’s newest Telephone Hybrid-2 is the active version of the well known passive one, successfully
sold over the last 5 years.
Its concept originates from many demands for a more sophisticated hybrid with more features.
The Telephone Hybrid-2 is an analogue unit with digital control and features like ducking making
intelligibility a lot better in broadcast..
What is a telephone hybrid?
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 canceling out the unwanted signal they also facilitate two-way
communication down a single telephone line.
Each hybrid has a telephone line connection, a handset connection and separate connectors for audio
input and output from a broadcast mixer, or other professional audio source.
A large proportion of D&R hybrids are used in radio and television broadcasting applications allowing
external callers to be connected to the studio mixing console. Most of the other units are supplied to
communication operations allowing extremely effective conversion between 4-wire audio circuits and
standard telephone lines.
Front panel lay-out
CONNECT BUTTON:
(RING)
Line connect switch to connect and disconnect calls from the telephone line.
It can be remotely driven by connecting a switch to the GPIO sub D
connector.
LC:
Variable Low Cut filter to filter out unwanted low frequency noise.
HC:
Variable High Cut filter to filter out unwanted high frequency noise.
Ducking
Indicates when caller’s signal is reduced.
RECEIVE:
Level control for incoming signal from caller.
SEND:
Level control for outgoing signal to caller.
.