Thanks Spanky! I am out of town till Sunday, when I get home I will try your suggestion. I just emailed Ryan to see about exchanging the unit for a new one. I am pretty sure that the popping sound is a shielding, filtering or grounding problem. I'm no novice to electronics and I also talked to a Hi Fi repairmen at one of the local hi end stores here in Minneapolis and he agrees that what we are expriencing is not just digital switching on and off. I'll keep you posted.