Studio Technologies Model 45A 2-Wire Analog Audio to 4-Wire Analog Audio Interface

ITEM #: STCH-MODEL-45A MFG #: MODEL 45A

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MODEL 45A - Overview

The Studio Technologies Model 45A is designed to interface a 2-wire full-duplex party-line intercom circuit with a 4-wire audio circuit associated with a matrix intercom system. Other specialized audio system interfacing applications can also be supported. Applications for the Model 45A include television sports and special event broadcasting, theme park and theater installations, corporate events, and industrial testing environments.

The Model 45A provides a full-featured 2-channel interface which includes two hybrid circuits with automatic nulling capability. The analog hybrid circuitry provides excellent audio quality and high return-loss. For flexibility, the Model 45A can be powered by the connected 2-wire party-line circuit or by means of an external source of 24 Vdc. When powered by an external source the Model 45A is capable of supplying DC power to the 2-wire intercom circuit, allowing direct operation of devices such as user beltpacks. Audio level meters provide confirmation of system performance during setup and operation. Standard audio connectors are used for all input and output signals. The Model 45A'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 45A units can be mounted in a single space of a standard 19-inch rack enclosure or one unit can be mounted in a speial 10.5-inch rack.

  • Features:

    • 2 Wire to 4 Wire Intercom Converter
    • Portable "throw-down" or rack-mount use
    • Analog hybrids with auto null capability
    • Input and output level metering
    • Excellent audio quality
    • Flexible powering
    • Standard audio connectors
    • Transformer-coupled 4-wire inputs and outputs
    • Integrated 2-wire intercom power source
     
  • Specifications:

    • General Audio:
    • Frequency Response: ±;2.5 dB, 100 Hz to 8 kHz
    • Distortion (THD+N): <0.2%, measured at 1 kHz, 4-wire input to 2-wire interface pin 2
    • Signal-to-Noise Ratio: >55 dB, measured at 1 kHz, 4-wire input to 2-wire interface pin 2

      2-Wire Party-Line Intercom Interface:
    • Type: 2-channel party-line, unbalanced (pin 1 common; pin 2 DC with channel 1 audio; pin 3 channel 2 audio)
    • Compatibility: single- and dual-channel intercom systems such as from RTS® and Clear-Com®
    • Impedance-Normal: >10 k ohms
    • Impedance-2-Wire (PL): Power Source Mode: 200 ohms
    • Nominal Level: -10 dBu
    • "Mic Kill" Signal: square wave, 24 kHz, ±;1%
    • 2-Wire Power Source: 30 Vdc nominal, 300 mA maximum

      Hybrids: 2
    • Topology: 3-section analog circuitry compensates for resistive, inductive, and capacitive 2-wire party-line loads
    • Nulling Method: automatic upon user initiation, processor implements digital control of analog circuitry; settings stored in non-volatile memory
    • Nulling Line Impedance Range: 120 to 350 ohms
    • Nulling Cable Length Range: 0 to 3500 feet
    • Trans-Hybrid Loss: >40 dB, typical at 800 Hz

      4-Wire Inputs: 2
    • Type: transformer-coupled, capacitor isolated
    • Impedance: 13 k ohms
    • Nominal Level: +4 dBu
    • Maximum Level: +22 dBu

      4-Wire Outputs: 2
    • Type: transformer-coupled, capacitor isolated
    • Impedance: 50 ohms nominal
    • Nominal Level: +4 dBu
    • Maximum Level: +20 dBu into 2 k ohms

      Meters: 4
    • Function: displays level of 4-wire inputs and outputs
    • Type: 5-segment LED, modified VU ballistics

      Connectors:
    • 4-Wire Line Inputs: 3-pin female XLR
    • 4-Wire Line Outputs: 3-pin male XLR
    • 2-Wire (PL) Interface: 3-pin male and female XLR
    • External 24 Vdc Input: coaxial power jack, 2.1 x 5.5 mm, locking bushing, compatible with Switchcraft® S760K plug

      Power Requirements:
    • External: 24 Vdc nominal, acceptable range 20 to 28, maximum required current 750 mA @ 20 V. Universal mains input/24 Vdc power supply shipped with each unit.
    • 2-Wire Party-Line (when serving as source): 24 to 32 Vdc, 175 mA

      Dimensions - Portable "Throw-Down" Version (Overall):
    • 8.7 inches wide (22.1 cm)
    • 1.72 inches high (4.4 cm)
    • 8.3 inches deep (21.1 cm)
    • Weight: 1.8 pounds (0.82 kg), rack-mount front panel adds 0.2 pounds (0.09 kg)
    • Mounting: single-unit (M45ARM-1), dual-unit (M45ARM-2), or "1/2-rack" (M45ARM-3) rack-mount front panels; single-unit and dual-unit panels use one space (1U) in a standard 19-inch rack, "1/2-rack" panel uses one space (1U) in a special 10.5-inch rack.
     

MODEL 45A - Required Accessories

    California Residents:
    WARNING:
    Cancer and Reproductive Harm - www.P65Warnings.ca.gov