Hello- Thanks for the replies. Gutbucket- Sorry if I was unclear- the M-10 is battery powered. I meant that every wall outlet I get near is a source of hum I can hear in my phones. I'll try cleaning again. Thx. Beatkilla- Yes. I'm a sound designer and have used the DSM6s for ambiance capture and some 1st person SFX recording. I've also done some 1st person dialog recording. The mics can decode in an interesting way when mixed/played in various surround/"spatial" formats. They are just another cool tool in the toolbox! Thanks again, everyone. I'll update if I figure out what the problem is. Cheers- Ken