The Evertz 7707AT13-8U is a modular fiber optic transmitter card designed for installation within the 7707-series backplane chassis, specializing in the multiplexed transport of eight channels of unbalanced AES/EBU digital audio over a single optical fiber. This system addresses the need for reliable, long-distance, and noise-immune audio signal distribution in large broadcast facilities, campuses, or between remote locations. The card accepts eight discrete AES audio inputs, typically on RCA or BNC connectors (unbalanced 75-ohm format), multiplexes them into a single data stream, and modulates a 1310nm Fabry-Perot (FP) laser for transmission over single-mode fiber. This approach consolidates multiple critical audio paths into one fault-tolerant fiber link, dramatically reducing cable bulk and eliminating concerns about electromagnetic interference, ground loops, and distance limitations inherent in copper-based audio cabling.

Engineered for broadcast-critical performance, the transmitter ensures signal integrity through high-quality electrical-to-optical conversion. The 1310nm wavelength is a standard for medium-distance fiber optic communication, offering a balance of performance and cost-effectiveness. The card includes status monitoring for key parameters such as optical output power and input signal presence, allowing for proactive maintenance. It is designed to work in tandem with a corresponding receiver card (such as a 7707AR model) at the far end of the fiber link, which demultiplexes the stream to recover the eight original AES channels. This creates a transparent, point-to-point audio "pipe" that behaves as if the sources and destinations were locally connected with very short cables.

As part of the modular 7700-series ecosystem, the 7707AT13-8U benefits from the chassis's centralized power, cooling, and management. It can be combined with video, data, and other audio transport cards in the same frame to create a comprehensive fiber aggregation node. Configuration and monitoring are typically handled via the chassis's system controller. This card provides broadcast engineers with a robust, high-density solution for distributing pristine digital audio over fiber infrastructure, essential for inter-building links, contributions to remote production trucks, or any application where audio quality and reliability must be maintained over extended distances.