@craigl59 The noise happens with the IEMs plugged in even with no source input connected so just the power from ADI-2 DAC. @gepardcv I'm retarded. The power connector is actually two prong so a cheater plug and @AllanMarcus suggestion won't work. Ugh. I did try it with my Furman but the AC was on so it wasn't quiet enough to check. I'll double check this later. Any way to do a trickle charge from powered battery bank or something to completely eliminate the grid power?