Studio Technologies MODEL 46A Dual 2-Wire Analog Audio to 4-Wire Analog Audio Interface

The Studio-Tech Model 46A 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 46A provides two independent full-featured 2-channel interfaces. Each interface contains two hybrid circuits which include automatic nulling capability.

Key Features

• Two 2-channel party-line intercom interfaces
• Four analog hybrids with auto null capability
• Input and output level metering
• Excellent audio quality
• Integrated intercom power sources
• Standard audio connectors
• Transformer-coupled 4-wire inputs and outputs
• 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 optional 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)
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%
Internal Power Source
30 Vdc nominal, 315 mA maximum
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
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 Vdc; 2 mA minimum for operation, 20 mA maximum
Functions
auto null interface 1, auto null interface 2, and "mic kill"
AC Mains Requirements
100-240 V (-15/+10%), 50/60 Hz, 34 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
4.6 pounds (2.1 kg)