EA915X DIGITAL TELEPHONE HYBRID
INSTRUCTIONS FOR USE
EELA AUDIO Het Riet 8A
5431NM CUIJK The Netherlands
Page 5
Purpose.
The main purpose of the EA915X is to be used as an interface to make a connection between a telephone
line and a mixing console, with the highest possible quality and reliability. To obtain this purpose, the
EA915X uses a Digital Signal Processor which reduces the crosstalk, normally existing in a hybrid
circuitry, to a minimum.
Realisation.
To realise this purpose, a design has been set up with a by
TELEFICATION
successfully tested and
approved hybrid circuitry from the EA815/1 (analogue hybrid) and attached to it a 16-bit
D
igital
S
ignal
P
rocessor of Analog Devices and a 16-bit Codec of Crystal together forming the heart of
the digital echo canceller. FLASH technology is used for permanent storage of the settings for the
echo canceller. A microprocessor takes care of the internal and external control.
Installation.
Check the equipment for any transport damage after unpacking.
Before installation and taking the unit into service, please read this manual.
Make sure the unit will be installed in any equipment bay with sufficient unobstructed air
circulation so that the maximum air temperature in the equipment environment will not be
exceeded.
Before mounting the EA915X into a 19" rack, the user should make some settings which are
dependent on the use of the unit and its infrastructure. These settings can be done over 4
DIL switches which are reachable on the rear of the unit. Make sure the power is not connected (yet) when
adjusting the switches.
Dilswitch Settings.
DIL SWITCH SETTINGS
CALL
CALL
CALL+READY
1
ON
OFF
REMOTE ON/OFF
CONTINUE
PULSE
4
ON
OFF
CANCELATION
CONTINUE
MANUAL
STORE
2
ON
OFF
ON
3
OFF
OFF/ON
ON
Remark: Standard factory settings are marked in grey.
Dilswitch 1.
With this dilswitch the behaviour of the RING-output (Opto-isolator) is set. In the ON-position this
RING-output can be used as indication of an incoming call.
In the OFF-position the output can be used for signalling of an incoming call as well as indication
of the ON/OFF status of the hybrid. This RING-output can be found on the 9 pin D-type connector
marked IN/OUT/REMOTE.
