Stereo Audio Ground-Loop Isolator and Filter with RCA connectors. Eliminates ground loop noise between any audio source such as DVD player, MP3 player, or notebook PC and audio equipment. Perfect frequency response of +.03 db from 20 to 20,000Hz. Uses proprietary audio transformers and filters for total elimination of any spurious buzz and hum in the audio.The unit is simply inserted in series with the audio and it literally eliminates the ground connection between the two sides, passes all the audio while filtering out any noise using high performance audio transformers. In most cases the unit can be used in either direction, however it is designed so that the male RCA connectors on the molded cable are used as input and the female RCA connectors on the box are outputs. The input side incorporates DC blocking capacitors. Some audio source equipment may have a certain DC bias voltage on their audio output connectors. In order to isolate this Bias level from the transformer coils, DC blocking capacitors are employed by the GLI-RCA. The isolated output is automatically AC coupled and has no bias. It uses 1:1 audio transformers therefore it does not change the impedance. So if your load is 5K Ohm, adding the isolator in front of it, the source still sees a 5K Ohm load impedance.