Removes AC noise: The Pyle hum eliminator removes 60Hz AC hum caused by ground loops that act like Radio antennae (loop antenna). breaks the ground loop safely making it impossible for the signal lines to pick up the AC noise in the first place | Passive device: The noise isolator is a passive device which does not require power to operate. Equipped w/ ¼” TRS phone and XLR inputs and outputs on 2 channels. Automatically converts unbalanced to balanced signal without any signal loss | Compact design: This noise filter device features a high performance Ultra compact and portable design allowing you to easily bring it anywhere. It has high quality components and rugged construction while maintaining the highest sonic quality | 1:1 ISOLATION TRANSFORMERS: The 1:1 isolation transformer is responsible for breaking the ground loop or the loop antenna that prevents buzz for a clear sound. Also responsible for balancing audio lines. Device accepts mono or stereo connections | Worry-free Shopping: with the pylepro Phe400 hum/noise eliminator, we are confident of the quality of our product, therefore, we offer a 30 day money back guarantee, No questions asked