Expandable Digital to Analog Converter (EDAC)


EDAC Usage

EDAC equipment is used in conjunction with many Telephone Call Recording Systems/Voice Loggers in the marketplace to allow connection of digital PBX handsets to the analogue inputs of the voice loggers.

The Expandable DAC recording interface translates proprietary PBX switch data to an analogue format used by call recording hardware.

Expandable one port at a time, the equipment supplies quality digital conversion for a wide range of PBX types including Nortel Networks, Aspect, NEC, Avaya (Lucent), Siemens, Ericsson and Panasonic.


Expandable Digital-to-Analog (EDAC) recording interface

EDAC Key Features

  • Base unit accommodates twelve individual port cards
  • Installs in the switch room with minimal wiring and assembly
  • Secure system– agents cannot disconnect recording at the desktop
  • Industry standard Amphenol Cable Connection
  • Cable Tails available in standard 3M lengths, other lengths on application


The Expandable DAC monitors the digitized voice information carried on the Digital Extension telephone line and reformats the digitized information into a standard 600 ohm analogue format required by most recording equipment.

The unit captures both sides of a conversation and sends audio to the recorder only when a call is

This is especially useful with the search features of recorders that look for silent periods between conversations.

Since there is no open microphone, as with simple recording systems, recording occurs only during active phone conversations.

Therefore, office conversations held between calls are not recorded and remain private.

EDAC Configuration

The diagram below demonstrates the connectivity between the Expandable DAC and the digital telephone system and Digital Handsets to be recorded.

The Expandable DAC bridges across each digital telephone line to be recorded and provides a corresponding audio pair out to the recorder.

EDAC Configuration Diagram
EDAC Configuration Example


Loop length is system dependent — system specific distance details are available from the EDAC Manual.


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