Microphone phantom power when using RJ45 adapters

Updated by Bryan Jones


This document covers the use of many standard "dongles" that adapt from the RJ45 connectors on the back of a microphone xNode to a microphone, specifically when phantom power is required for condenser microphones. Some examples of the cables look like this.

If you are using DYNAMIC microphones, using your own cables, or using breakout cables on the DB25 connectors on the xNode, this article does not apply to you.


The wiring standard for these adapters was created circa 2000 by then Radio Systems owner Dan Braverman to simplify audio connections using standard, readily available tools and cables. Although there are a number of companies producing these "dongles," they have become ubiquitously referred to as "studio hub" dongles; however, StudioHub® is a registered trademark of Angry Audio.

Wiring to your microphone when phantom power is required

When using the types of adapters shown above, you must use a shielded Cat-5 cable to connect to the xNode. The reason you must use shielded cables is that the ground required for the phantom power is carried on the shield conductor. Using unshielded cable results and no ground. No ground results in no phantom power. No phantom power results in no working condenser microphones.

Identifying shielded cables

Shielded Cat-5 cables can be identified by a metal band around the RJ-45 connector like this.

Cable markings

Cables may be marked with the following;

  • UTP - often called "universal twisted pair;" however, it stands for UNSHIELDED Twisted Pair
  • STP - Shielded Twisted Pair
  • FTP - Foil Twisted Pair
Either STP or FTP cables are acceptable

Let us know how we can help

If you have further questions on this topic or have ideas about improving this document, please contact us.

How did we do?