A hum eliminator, also known as a ground loop isolator, is a device used in music production and audio engineering to eliminate unwanted hum or buzz in audio signals caused by ground loops.

A ground loop occurs when there are multiple paths to ground in an audio system, which can cause electrical interference and result in a low-level hum or buzz in the audio signal. This is a common problem in audio systems that have multiple pieces of equipment or that are located in environments with electrical interference.

A hum eliminator is designed to interrupt the ground loop and break the connection between the audio equipment and the ground current. It typically works by using an audio transformer to isolate the audio signal and prevent the flow of ground loop current through the audio cables.

Hum eliminators are available in a variety of different types and configurations, including passive and active models. Passive hum eliminators do not require any power source and work by using audio transformers to isolate the audio signal, while active hum eliminators use active circuitry to amplify and filter the audio signal.

Hum eliminators can be useful tools for audio engineers and producers who are dealing with unwanted hum or buzz in their audio signals. However, it is important to note that they are not a cure-all for all audio issues and should be used in conjunction with other troubleshooting and problem-solving techniques to ensure the best possible audio quality.