The Truth About Sending Phantom Power Through TRS Connectors

TRS (Tip-Ring-Sleeve) connectors are commonly used in various audio applications, including headphones and guitar amplifiers. However, can you use these connectors to send phantom power? This article explores the feasibility and potential risks of sending phantom power through TRS connectors, comparing it with the more common XLR connector.

Understanding Phantom Power

Phantom power is a method of powering certain types of microphones and other active electronic devices via the interphone cables between a mixing console and the device. It is typically carried through the tip and ring of an XLR connector and is referenced against the shield. This method ensures reliable and consistent power delivery, as the power is independent of the signal path.

TRS Connectors: A Closer Look

TRS connectors, commonly found on 3.5mm and 6.35mm audio cables, consist of a tip, a ring, and a sleeve. They are used for balanced and unbalanced audio signals. In stereo applications, the tip usually represents the left channel, the ring the right channel, and the sleeve is the ground. Similar to the XLR connector, the TRS connector can carry both signal and power, but there are key differences.

Can You Send Phantom Power Through TRS Connectors?

Technically, it is possible to send phantom power through a TRS connector as long as both ends are wired to handle it. The signal is passed differentially between the tip (positive) and the ring (negative), with the shield functioning as the ground. A blocking capacitor is typically used to separate the signal from the power. However, the design and implementation of phantom power through a TRS connector can lead to issues, such as potential PCB shorts and signal integrity problems.

Comparing TRS and XLR Connectors for Phantom Power

The XLR connector is specifically designed to connect earth first, then the hot and cold conductors together. This design ensures the continuous delivery of phantom power while changing out microphones or cables, maintaining safety and reliability. In contrast, the TRS connector, while capable of carrying both signal and power, lacks the same level of safety and reliability due to its design and the risk of shorts when inserting or removing the connector.

Practical Considerations

While you can indeed send 48v phantom power through a balanced TRS connector and cable, doing so is inadvisable. The act of inserting a TRS connector into a mixer, especially through an XLR to TRS adapter, can short out the phantom power circuit, damaging the microphone or causing mechanical damage. Additionally, the limited conductor configuration (tip, ring, sleeve) of the TRS connector means that only positive and negative conductors are available for signal or power.

Conclusion

In conclusion, while it is possible to send phantom power through TRS connectors, the risks and complications involved make this method less ideal. The XLR connector, with its earth-first design and more robust protection, is the preferred choice for reliable phantom power delivery. Always ensure the proper connectors and adapters are used to avoid potential damage to equipment and to ensure safe and reliable operation.