Studio Technologies MODEL-2
IFB Plus Central Controller

MODEL-2

The Model 2 one rack-space unit offers a wide range of features all optimized for mobile applications. It contains two independent IFB channels. Each channel has a complete set of controls and indicators. Program source select switches allow one or more of the four program inputs, as well as incoming audio from the two telephone interfaces, to be selected as program audio. Program level controls allow adjustment of the selected program sources. Channel audio level is displayed by 5-segment LED meters. Channel interrupt activity is displayed by LED indicator lights.

Program Inputs
The Model 2 has four program inputs that can be individually assigned to the two IFB channels. Each program input has a trim pot that allows the nominal +4 dBu input level to be adjusted over a ±8 dB range. During interrupt activity, program audio is muted. A sophisticated analog switch is used to give a noise-free mute with absolutely no clicks or pops.

IFB Outputs
Each IFB output (program and interrupt audio) is sent to four places: the talent amplifier output, a line output, telephone interface 2, and the monitor amplifier. The talent amplifier output provides IFB channel 1 and 2 audio, along with power to support any combination of up to four Model 32A or Model 33 Talent Amplifier units. The balanced line-level output can be used to drive wireless IFB transmitters, etc. Using telephone interface 2, IFB audio from channel 1 or 2 can be used to originate an IFB feed. An external speaker or headphones can be connected to the internal 4-watt amplifier, allowing monitoring of either IFB channel.

Internal Interrupt Microphone
An electret-type microphone is contained behind the Model 2’s front panel. Two switches allow the internal microphone to interrupt either IFB channel with clean, clear audio.

Telephone Interfaces
The Model 2 contains two telephone interfaces. Each interface can be used to bring program or interrupt audio into the Model 2. In most applications, telco signals will be used as program audio sources. In special situations they can serve as an interrupt source in conjunction with the voice operated (VOX) interrupt function. The receive audio level of each telephone interface is adjustable using a front panel control. In addition to receiving audio, interface 2 can be used to originate an IFB feed. Using this function, audio from IFB channel 1 or 2 can be sent to a studio, a remote vehicle, or a portable telephone.

The telephone interfaces are unique in that they allow two very different telephone "lines" to be correctly interfaced. Each interface can be set to operate with a telephone line or a standard audio signal. A telephone line would be a 2-wire DC-biased circuit provided by a local telephone company. A standard audio signal could be provided by, for example, a cellular telephone.

The two operating modes supply distinct feature sets. When an interface is set to the telephone line mode, full monitoring and control is implemented. Each interface contains a switch that allows the telephone line to be seized (taken off hook) or hung up. When an interface is active, telephone line loop current is monitored. The interface will automatically hang up if a telephone company provided disconnect signal is received. Interface 2 also implements an auto answer function, "answering" the telephone line when ringing is detected.

When an interface is set to handle a standard audio signal, the loop-current-specific features are disabled, and the interface operates as a transformer-coupled balanced audio input. The input and output audio levels are optimized for use with telephone-type audio signals.

Voice Operated (VOX) Interrupt
For special applications, the Model 2 allows an audio signal to serve as both an interrupt audio source and a control source, eliminating the need for a push-to-talk button or contact closure. A switch is used to select the VOX audio source. The choices are: receive audio from Telephone Interface 1, receive audio from Telephone Interface 2, or audio from the VOX line-level input.

Monitor Amplifier
The Model 2 contains a 4-watt audio amplifier, allowing either IFB channel to be monitored. A click-free analog switch mutes the monitor output when the internal microphone is actively interrupting an IFB channel. In addition, Model 22 or Model 24 Access Stations can be configured to mute the monitor amplifier upon interrupt.

Audio Quality
Great care was taken to make the Model 2’s audio sound clear and crisp. The unit’s specifications belie its seemingly humble function as an IFB unit. This unit sounds great!

Each IFB channel includes a studio-quality compressor circuit. The compressors even out variations in interrupt audio signals, making talent cues more intelligible and helping reduce the risk of abnormally high signal levels from reaching the talent’s ears.

Installation
For easy installation and maintenance, standard connectors are used throughout, including male and female XLR-type, ¼-inch tip and sleeve, 9-pin D-subminiature, and modular telephone jacks. Mains power is factory selected for 115 or 230 V, 50/60 Hz. The Model 2 is mounted in one space of a standard 19-inch rack.

Our Part #  MODEL-2