ycable

A Y cable, also called a Y-adapter or Y-splitter, is a cable arrangement that branches from a single connector into two connectors, forming a Y-shaped configuration. It is used to route a signal from one source to two destinations or, in some cases, to connect two devices to a single input. Most Y cables are passive electrical conductors with shielding and are designed for low-power signals. Common formats include 3.5 mm stereo audio Y-cables, RCA Y-splitters, and USB power Y-cables.

In audio applications, a Y splitter can divide a stereo signal from a single source to two headphones or to two amplifiers. Caution is advised: simply wiring two outputs together or feeding two active sources into one input can cause impedance mismatches, crosstalk, or damage. For reliable signal combining or routing, a mixer, buffer, or resistor-based combiner is preferred.

USB Y-cables are typically used to draw additional power for devices such as external hard drives or LED accessories. They do not increase data bandwidth and may not be supported by all devices. Some USB Y configurations simply combine power from a second port while sharing a single data line, which can lead to power management or compatibility issues if not specified by the device manufacturer.

Limitations of Y cables include impedance differences, signal degradation at long lengths, and potential harm when connecting two active sources. When in doubt, use purpose-built equipment such as splitters designed for the intended application or consult device manuals. See also: splitter, adapter, mixer.