How to Mod a Phantom With a USB

Condenser microphones require a phantom power source for operation.

Condenser microphones utilize a phantom power supply instead of batteries or an electrical outlet. This phantom power can come from a USB recording interface on your computer. Because microphones are very sensitive instruments, you need to adjust them properly to achieve the desired sound. The availability of USB interface recording gear on your computer makes this task much easier to do.

Things You'll Need

• Condenser microphone
• XLR cables (2)
• USB cable

Instructions

1. Turn on your computer then choose the audio input source that is best compatible with your phantom device. Your computer will typically have multiple USB ports available. Test each USB port until you find the one that works best with your device. If you are not sure which USB port works best, use a USB 2.0 port by default.

2. Plug one end of a USB connector into your phantom-powered mixer’s USB output. Most phantom devices come with a USB cord.

3. Insert the opposite end of the USB connector into the USB port on your computer. Because USB delivers DC current, your computer can also power your phantom device.

4. Turn all of the volume controls to zero on the phantom mixing board.

5. Plug the positive and negative XLR cables for your condenser microphone into the “Output” jacks on the mixing board.

6. Turn on the phantom power by flipping the "48v" button on the mixer's interface to the "On" position.

7. Raise the volume on the microphone loud enough to pick up the audio but not so loud that the sound distorts.

8. Adjust the music and microphone volume levels by turning the “Master Volume” knob.

9. Press the "Record" button at the bottom right-hand of your computer’s audio-recording software and speak into the microphone to record your voice. While recording, stand at least 4 inches away from the microphone to prevent distortion. Turn on the main volume knob on the mixer to the desired loudness level while recording. Adjust the mixer volume and tone controls until you get the desired sound quality from your microphone.

Tips & Warnings

• Ribbon microphones do not require an external power source. Connecting a ribbon microphone to phantom power could damage its electronic parts beyond repair.

• Before connecting or disconnecting your microphone to a power source, be sure to turn down all of the volume controls to prevent a power surge that could permanently damage your microphone.

References

• Tangible Technology: Phantom Power and Microphone Interconnect Basics from the "Ground" Up!
• "Recording on a Budget: How to Make Great Audio Recordings Without Breaking the Bank"; Brent Edstrom; 2010