The Model 371 Intercom Beltpack combines the features offered by broadcast-style 2-channel party-line (PL) intercom user devices with a single-channel listen output and a 4-pin male XLR headset interface connector. This output arrangement allows deployment in PL intercom applications where support for single-ear headsets is desired. These headsets, which utilize dynamic microphones, are widely used in theatrical, corporate, and industrial applications where it's important to have one ear remain open to ambient audio signals.

The Model 371 uses the advanced capabilities that Dante audio-over-Ethernet can provide. Over a standard IP network, multiple Model 371 units can be used in PL intercom applications with help from an external Dante-enabled audio matrix. Or, units can be used "point-to-point" or directly interfaced with ports on compatible matrix intercom systems. Only a single Power-over-Ethernet (PoE) connection is required for operation. Key user features can be easily configured including microphone preamplifier gain and talk button operation. Additional user features include integrated sidetone, remote microphone off, and call alerting. This capability, along with the great audio quality provided by the digital audio signal path, offers a superior user experience.

Set up and configuration of the 2-channel Model 371 is simple. An etherCON® RJ45 jack is used to interconnect with a standard twisted-pair Ethernet port associated with a local-area network (LAN). This connection provides both power and bidirectional digital audio. A broadcast or intercom-style headset with a dynamic microphone interfaces to the unit using a cable-mounted 4-pin female XLR connector. The connected headset can be either single- or dual-ear models but the Model 371 has only a single channel headphone audio output; the two listen audio channels are always combined and sent to the one audio output. Three DIP switches are used to establish the unit's operating parameters. Two "push-in/push-out" rotary level controls make it easy to set the headphone output volume as well as maintaining the desired settings. The Model 371's enclosure is made from an aluminum alloy which offers both light weight and ruggedness. A stainless steel "belt clip," located on the back of the unit, allows direct attachment to a user's clothing.

The audio quality of the Model 371's two audio channels is excellent, with low distortion, low noise, and high headroom. Careful circuit design and rugged components ensure long, reliable operation. A wide range of applications can be supported, including TV, radio, and streaming broadcast events, corporate and government AV installations, and industrial facilities.

• Dante audio-over-Ethernet technology
• Two independent talk and listen channels
• 4-pin male XLR headset connector
• Integrated call function
• Configurable operating parameters
• Power-over-Ethernet (PoE) powered

Audio Channels

• 2 talk, 2 listen

Power Source

• Power-over-Ethernet (PoE): class 1 (very low power, less than or equal to 3.84 watts)

Network Audio Technology

• Type: Dante audio-over-Ethernet
• Bit Depth: up to 24
• Sample Rate: 48 kHz
• Number of Transmitter (Output) Channels: 2
• Number of Receiver (Input) Channels: 2
• Dante Audio Flows: 4; 2 transmitter, 2 receiver

Network Interface

• Type: twisted-pair Ethernet, Power-over-Ethernet (PoE) supported
• Data Rate: 100 Mb/s (10 Mb/s Ethernet not supported)

Microphone Input

• Type: unbalanced, for use with dynamic microphones
• Gain: 40 or 46 dB, selectable, ref. –60 dBu input to Dante output (–20 dBFS nominal)
• Frequency Response: 50 Hz to 10 kHz, –3 dB
• Distortion (THD+N): less than 0.02%
• Dynamic Range: 75 dB

Compressor

• Threshold: 1 dB above nominal level (–19 dBFS)
• Slope: 2:1
• Status LED: compressor active

Headphone Output

• Type: single-channel (combination of audio input 1 and audio input 2)
• Compatibility: intended for connection to headsets or earpieces with nominal impedance of
• 50 ohms or greater
• Maximum Output Voltage: 3.8 Vrms, 1 kHz, 150 ohm load
• Frequency Response: 20 Hz to 10 kHz, –3 dB
• Distortion (THD+N): less than 0.002%
• Dynamic Range: greater than 100 dB

Call Signal Support

• Method: 20 kHz, ±800 Hz, within audio channels
• Call Send Level: –20 dBFS
• Call Receive Level: –27 dBFS minimum

Connectors

• Headset: 4-pin male XLR (intended for interfacing with a cable-mounted 4-pin female XLR
• connector wired with pin 1 mic –/shield; pin 2 mic +; pin 3 headphone –/shield; and pin 4
• headphone +)
• Ethernet: Neutrik etherCON RJ45
• USB: type A receptacle (located inside Model 371's enclosure and used only for firmware
• updates)

Dimensions (Overall)

• 3.6 inches wide (9.2 cm)
• 1.6 inches high (4.0 cm)
• 4.8 inches deep (12.6 cm)
• Mounting: intended for portable applications; contains integral belt clip; optional mounting bracket kit allows Model 371 to be permanently mounted
• Weight: 0.6 pounds (0.3 kg)