The Model 44D Audio Interface provides a simple yet high-performance means of interfacing two channels of analogue line-level audio to and from applications that utilize Dante® audio-over-Ethernet media networking technology. Two Model 44D units can also provide one-to-one signal paths, two in each direction, over a standard local area network (LAN). In addition, the unit supports transport of status signals or contact closures between Model 44D units and other compatible products. There are two general-purpose inputs (GPI) and two general-purpose output (GPO) on each Model 44D.
A special operating mode allows the Model 44D to serve as a tone generator rather than an audio interface. When configured for the tone generator mode 1 kHz and 18 kHz sine-wave audio signals are available in both the analogue and digital domains.

The Model 44D is a fully professional product that offers the audio quality, features, and reliability required by 24-hour, on-air, and commercial applications. The two line-level audio inputs use standard 3-pin female XLR connectors for easy interfacing with balanced and unbalanced sources. The input audio signals are converted to 24-bit digital and then transported via the Dante interface. Two digital audio signals arrive into the Model 44D via the Dante interface and are then converted to analogue. Two 3-pin male XLR connectors on the Model 44D’s back panel provide balanced line-level outputs.

The Model 44D is designed as a bridge, using Dante to link analogue or other Dante interfaces found on devices such as matrix intercom systems, broadcast routers, and audio consoles. An Ethernet connection is all that’s required to make the Model 44D part of a sophisticated, networked audio system. Dante audio-over-Ethernet has found wide acceptance as an audio “backbone” due to its ease of use, high performance, strong interoperability, and wide adoption by a large number of equipment manufacturers. The Model 44D is a general-purpose “tool” that helps to expand Dante’s capabilities to facilities and equipment that primarily supports signals in the analogue domain.

Careful attention to circuit design and component selection ensures that excellent audio quality is maintained. Extensive filtering helps prevent damage or less-than-optimal performance should DC voltage, ESD (“static”), or strong RF signals be present on the associated analogue signals.

Configuration switches allow several Model 44D operating parameters to be selected. The nominal audio levels of the line input and line output functions can be independently selected. In this way compatibility with SMPTE® and EBU nominal signal levels is supported. Audio level meters provide confirmation of system performance during setup and operation. Two general purpose input and two general purpose output functions allow support for installer-selected applications, including party-line intercom call-light functions. Two LEDs provide a direct indication of the status of the GPO functions.

The Model 44D can be powered by Power-over-Ethernet (PoE) or an external source of 12 volts DC. Standard connectors are used for the line inputs and outputs, Ethernet, GPI/GPO, and DC power interconnections. The Model 44D’s enclosure has a “1/2-rack” 1U form factor and weighs less than two pounds, making it well suited for use in portable applications. Alternately, using one of the optional rack-mount front panels, one or two Model 44D units can be mounted in a single space (1U) of a standard 19-inch rack enclosure.

Key Features
 • Dante audio-over-Ethernet technology 
 • Input and output level metering 
 • Selectable input and output nominal levels 
 • Excellent audio quality 
 • GPI/GPO support 
 • Tone generator mode for REMI applications 
 • PoE and 12 Vdc powering 
 • Standard connectors 
 • Table-top, portable, or optional rack-mount use

(Model44D)