Koss Bias Supply is a device that provides additional power to your Koss Sonic Boom Microphone Stereophones. If your computer does not supply enough power to operate your boom microphone, you must use the bias supply to power the microphone.

The bias supply is easy to use. Simply insert two "AAA" batteries into the bias supply, connect the bias supply to the 3.5 mm microphone plug on your Sonic Boom stereophones, and connect the attached bias supply plug to the microphone jack on your computer sound card or CD-ROM.

Once the bias supply is connected, you should be able to hear your voice through the stereophones when you speak into the microphone.