wingnut4772...I share your pain. I was talking with Steve on Friday of last week (he is very good) and I believe that I have three seperate problems: The first is the popping, like you describe above. The second is a loud thump when I turn on / off the system and the third hisssssssssssss.

Based on Steve's advice, I fixed the thump! You need to have your ICBM always on. Don't switch it on during power up or down. Also I have a Paradigm crossover circuit that also liek to stay up all night...

the popping sounds are last on my list. Hopefully you will all figure it out soon.

the hisssssssssss, is a wierd one. I was pretty certain that it was NOT 60 cycle hum, but I am not sure now. I pulled EVERY wire out of my system and began to build it up from the speaker back. So I had the speaker connected to the amp. That's it. Turn on the power and HISSSSSSSSSSSS.
I tried all of my amps (Outlaw M200's X 2, Marantz MA200 & MA150's X 6). Funny thing is that the Outlaw and the Marants MA200 are rock solid quiet in this test. It is only the MA150's. I will be trying to see if the AC power has been swapped (out of phase). I had this happen a long time ago, but since we have polarized plugs, I did not think of this until now.

The reason I bring this up is that this extra (voltage, whether AC or DC) may be contributing to the issue of the popping. I do nto think that it is the only source for the popping, but may be a primary culprit.

I will know more in a day or so....