I have tried all voltage settings.. 2V seems to be the best setting as well as eq settings on the ipod. I would like to determine if this is a ground loop problem that is coupling noise into the audio path. I'm out of town currently but I was thinking I could try unplugging the audio connector from the ice-link ( 6pin connector I believe) and connect a set of headphones to the ipod. If this eliminates the noise when listening over the headphones, it seems to me that an isolation transformer on the ice-link audio connections should fix the problem. I could then modify the icelink cable to include an isolation transformer.