Studio Technologies Model 74 – 5.1 Surround Monitoring Central Controller (100 Volt) Studio Technologies

The Model 74 Central Controller is a single rack-space unit that contains analog, digital, and power supply electronics. Four analog sources can be connected: two surround (5.1) and two stereo. In many applications the first surround input, Surround A, will be connected to a multi-channel output on an audio console or digital audio workstation. The second surround input, Surround B, will be connected to a playback device, such as a multitrack tape recorder or disk storage system. For film or video post applications Surround A would be considered the direct source, while Surround B would be considered the playback source.

Features:

• Supports 5.1 surround and stereo audio signals
• Analog inputs
• Analog outputs
• Integrated headphone cue system

The two stereo inputs, Stereo A and Stereo B, are provided for general-purpose use and can be connected to a variety of 2-channel direct and playback sources. For flexibility, the surround and stereo inputs are compatible with balanced or unbalanced signals having a nominal level range of –12 dBV to +6 dBu. Fifteen-turn trim potentiometers are used to precisely calibrate the input signals.

The Model 74 provides two 6-channel monitor outputs. A powerful system feature is the ability to configure the monitor outputs to meet the exact needs of an installation. In a “straight-ahead” application the monitor outputs might be configured to support two independent surround (5.1) loudspeaker systems. Alternately, one surround and one stereo monitor system could be connected. However, other more unique configurations are also possible. These include supporting alternate surround monitor speaker systems or adding additional LFE or surround speakers. The monitor outputs are electronically balanced and designed for connection to audio power amplifiers or amplified loudspeakers. Protection circuitry provides power-up and power-down protection of the connected loudspeaker systems.

Audio input and output connections are made using four 25-pin D-subminiature connectors. The Model 74’s audio path features low-noise, low-distortion analog switches for input source selection and laser-trimmed voltage-controlled-amplifier (VCA) integrated circuits for monitor level control. One 9-pin D-subminiature connector is used to connect the Model 74 to the Model 75 Control Console. A second 9-pin “D-sub” connector is used to interface remote control signals with the Model 74. The Model 74’s talent amplifier output uses a 3-pin male XLR-type connector. An infrared receiver module can connect to the Model 74 using a 3.5 mm jack.

An advanced 8-bit microcontroller provides the logic “horsepower” for the Model 74. AC mains power is connected directly to the Model 74, which is factory selected for 100, 120, or 220/240 V operation. The internal power supply utilizes two toroidal mains transformers for quiet audio operation.