Palmer PAL-PVILS Channel Merge Line Isolation BoxWe've all had the same experience before: At home the sound was crisp and clean but during the presentation it hums and buzzes and there is no time to figure out the cause. Here is where the Palmer vils comes in handy as it safely isolates the ground potentials of the laptop, media devices and PA systems from each other. (Calm returns and the audience and you can concentrate fully on your presentation again.) The Palmer vils has two unbalanced RCA