A Collection of Old-fashioned Optical Cables

Old-style optical cables, including TOSLINK audio cables and early fiber optic connectors like Biconic, ST, and FC, were revolutionary in their time but are now largely obsolete due to bandwidth and design limitations.

TOSLINK Audio Cables

TOSLINK, introduced in the 1980s, was the standard optical cable for digital audio connections. It transmits audio signals using light, which reduces electrical interference. However, its bandwidth is limited to roughly 384 Kbps to 1.5 Mbps, sufficient only for legacy surround sound formats like standard Dolby Digital and DTS 5.1. Modern audio formats such as Dolby Atmos, DTS:X, Dolby Digital+, and Dolby TrueHD cannot be transmitted over TOSLINK, meaning users miss out on high-resolution and spatial audio when using these cables. Essentially, TOSLINK compresses modern audio into a 5.1 signal, losing significant detail before it reaches the listener, making HDMI eARC a preferred alternative for contemporary setups .

Legacy Fiber Optic Connectors

Early fiber optic connectors were designed to physically align fibers for light transmission. Some notable old-style connectors include:

• Biconic connectors: Developed by AT&T, featuring a conic-shaped ferrule. Once cutting-edge, they are now obsolete .
• SMA connectors: Metal connectors used for multimode fibers before ceramic ferrules were introduced. They are declining in popularity .
• ST connectors: Bayonet-style connectors with a 2.5mm ferrule, widely used in multimode networks. Still in use but gradually being replaced by smaller, denser connectors .
• FC connectors: Designed for single-mode fibers, they improved on ST connectors by isolating cable tension and providing keyed ferrules for angle polishing . These connectors were often larger, less dense, and more difficult to terminate compared to modern LC duplex or MPO multi-fiber connectors, which support high-density patching and faster data rates in data centers .

Evolution of Fiber Optic Cables

Older fiber optic cables were less standardized and more sensitive to installation conditions. They required careful attention to bend radius, pulling tension, and termination techniques. Modern cables are often bend-insensitive, smaller in diameter, and easier to terminate, allowing for higher-speed data transmission and more forgiving installation practices. This evolution has made older connectors and cables largely obsolete in professional and consumer applications .

Summary

Old-style optical cables, whether for audio (TOSLINK) or data (Biconic, SMA, ST, FC), were essential in their era but are limited by bandwidth, size, and installation complexity. Modern alternatives like HDMI eARC for audio and LC/MPO connectors for fiber optic networks provide higher performance, support advanced formats, and simplify installation, making them the preferred choice today .