Studio Technologies Model 47A Dual 2-Wire Analog Audio to 4-Wire Analog Audio Interface

Studio Technologies Model 47A Dual 2-Wire Analog Audio to 4-Wire Analog Audio Interface The Model 47A is designed to interface 2-wire full-duplex party-line (PL) intercom circuits with 4-wire audio circuits associated with matrix intercom systems. Other specialized audio system interfacing applications can also be supported. The Model 47A provides two independent full-featured 2-channel interfaces. Each interface contains two hybrid circuits which include automatic nulling capability. The analog circuitry, under software control, provides excellent audio quality and high return-loss. The interfaces are compatible with powered and unpowered 2-wire party-line circuits. They are capable of supplying DC power to devices such as user beltpacks and user stations. Independent power sources are provided for both channels (pins 2 and 3) of each interface, allowing direct support for broadcast source assignment panel (SAP) applications. Configuration settings allow the 2-wire and 4-wire interface circuitry to be compatible with a range of nominal signal levels. Audio level meters provide user confirmation of system performance during setup and operation. Applications for the Model 47A include mobile and fixed television facilities, theme park and theater installations, and industrial testing environments. Standard audio connectors are used for all input and output signals. The Model 47A mounts in one space (1U) of a standard 19-inch rack enclosure and requires 100-240 V, 50/60 Hz for operation. Key Features Two 2-channel party-line intercom interfaces Four analog hybrids with auto null capability Input and output level metering Excellent audio quality 2-channel intercom power sources Direct support for broadcast SAP panel applications Standard audio connectors Universal input mains powered Technical Specifications General Audio Frequency Response +/-2 dB 100 Hz to 8 kHz Distortion (THD+N) <0.5%, 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 Connectors Inputs from 4-Wire 3-pin female XLR Outputs to 4-Wire 3-pin male XLR 2-Wire Party-Line Intercom 3-pin male XLR Remote Control 10-pin header, requires user-provided 10-pin ribbon connector assembly AC Mains 3-blade, IEC 320 C14 (mates with IEC 320 C13) 2-Wire Party-Line Intercom Interfaces 2 Type 2-channel party-line (PL), unbalanced (pin 1 common; pin 2 channel 1 audio or DC with channel 1 audio; pin 3 channel 2 audio or DC with channel 2 audio) Compatibility single- and 2-channel intercom systems such as from RTS and Clear-Com Impedance, External Power Mode >10 k ohms Impedance, Internal Power Mode 200 ohms Nominal Level -10 or -14 dBu, selectable “Mic Kill” Signal square wave, 24 kHz, +/-1% 2-Wire Party-Line Power Sources 4, 2 per interface Rating 30 volts DC nominal, 315 mA maximum, software monitored and controlled Hybrids 4, 2 per interface 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; null settings stored in non-volatile memory Nulling Line Impedance Range 120-350 ohms Nulling Cable Length Range 0-3500 feet, typical Trans-Hybrid Loss >40 dB, typical at 800 Hz 4-Wire Inputs 4, 2 per interface Type transformer-coupled, capacitor isolated Impedance 13 k ohms Nominal Level 0, +4, +6, or +8 dBu, selectable in tandem with nominal output level Maximum Level +22 dBu 4-Wire Outputs 4, 2 per interface Type transformer-coupled, capacitor isolated Impedance 50 ohms nominal Nominal Level 0, +4, +6, or +8 dBu, selectable in tandem with nominal input level Maximum Level +20 dBu into 2 k ohms Meters 8 Function displays level of 4-wire inputs and outputs Type 5-segment LED, modified VU ballistics Remote Control Inputs 3 Type optically coupled Input 3-32 volts DC; 2 mA minimum for operation, 20 mA maximum Functions auto null interface 1, auto null interface 2, and “mic kill” AC Mains Requirement 100-240 volts (-15/+10%), 50/60 Hz, 60 watts maximum Dimensions (Overall) 19.0 inches wide (48.3 cm) 1.72 inches high (4.4 cm) 8.4 inches deep (21.3 cm) Mounting one space (1U) in a standard 19-inch rack Weight 4.7 pounds (2.1 kg)