Palmer PWUPPER Passive Line Isolation Boxhe more complex the setup, the higher the chance of ground loops. With the Palmer wupper Line Isolation Box, everything is quiet again so you can enjoy your audio without humming and buzzing. The Palmer wupper is an isolation transformer in a robust aluminium and steel housing. It separates the ground potentials of two devices so that equalising currents are prevented and only your sound is transmitted clean and without interference. The Palmer wupper