Eela Audio EA815/2 User Manual

eela audio

EA815/2

Telephone hybrid

User guide

EA Broadcast / eela audio
http://www.eela-audio.com

Eela Audio EA815/2 Telephone hybrid

WARNING

Do not expose this appliance to rain or moisture. To reduce the risk of electrical shock, do not remove
cover. There are no user-serviceable parts inside. Do not attempt to repair the unit yourself, refer
servicing to qualified personnel.

CE-Product

This product is in conformity with the requirements of the CE directives.

This product should only be installed and used in installations as specified in this manual and should
only be used with the ancillary equipment and options and in the right environment according the
recommendations.
The supplier will not take any responsibility of damage to or induced by this product caused by using
the equipment in any not specified application or connecting items or equipment, in any way or
environment other than specified.

General Information

Cleaning

Clean the outside of this product with a soft cloth. Do not use any cleaning detergents like alcohol,
white spirit or ammonia based fluids to clean this product. This can severely damage the finish of the
product.

Eela Audio EA815/2 Telephone hybrid

SYSTEM DESCRIPTION

The design goal for EA815/2was to produce a telephone hybrid with the best results and the
easiest operation. There is only ONE operator control; the ON switch to connect the PTT-line to
the hybrid instead of a telephone. The function can be remote controlled.

The power supply is a wide range “universal” adapter suitable for 100 to 240 Volts, 50/60 Hz and
comes with Euro, UK and US/Japan style wall plugs. Please note that these power supplies will
not work with older hybrids nor will the previous transformer adapters work with the new units.

The hybrid itself is composed around two transformers with a PRESET BALANCE NETWORK.
This preset network needs to be trimmed only at installation for best balance on an average line.
Practice has shown, that the connection to the first exchange is determining for the setting and in
most cases this is always the same line.

The best results can be obtained when a DIRECT telephone line is used, not routed via a house
telephone system.

To achieve the best damping of the send signal in the receive signal, this hybrid employs VOICE
CONTROL in combination with the preset balance.

The following processing is done:

The SEND signal is bandfiltered and limited, so not to spoil the damping by too much level and out
of band signals.

The RECEIVE signal has:

* VOICE CONTROL of the gain by the SEND signal. As soon as the studio starts talking,

the gain of the receive chain is reduced to lower the crosstalk over the hybrid. By this
action, the direct signal of the microphone is not spoiled by the crosstalk from the hybrid
and so gives a cleaner result.

* Also some filtering is employed to reduce out of band signals like hum, dailing pulses etc.

GAINS for SEND and RECEIVE are adjustable through the frontpanel.