Have an ip office (69) revision trying to have external MOH with the same music source playing to an amplifier for background music over their paging speakers. I have my MOH cable tapped into the feed cable(with a mono plug)that goes to the amp(a rca plug). Whenever I plug into the ksu it messes with the amps volume & no way of adjusting. Also as soon as I plug it in & I have my buttset on the output of the amp my buttset starts to ring like their is higher voltage coming out of the ksu, which is causing the no adjustment of the volume on the amp. Does the ksu have to be a stereo plug? Should I try to split the inputs where the music source is? Has any one tried making an analog ext. be the MOH input? Also have they come up with a background music over the phone? I know *34 does, but it busys out the phone. Looking for something like the ACS systems & the feature 19 turns on & off music. Thanks