I would still like to know what was happening right at power on, is everything still powering on at the same time? I looked at the Monster site for your surge suppressor. The literature says it should protect from transients from outside sources but says nothing of anything unpleasant that might be created by something plugged into the strip itself.

We talked about this but others here know the tech side to a much greater extent than I so will probably see something I would miss. Here I run everything from a single 15 amp circuit without issue but am careful to never turn on everything at the same time. Running separate surge suppression I keep the amps separate from anything with a processor on board. Based on what I am seeing in my own system my monster Adcom probably pulls its heaviest load at power on.

Here I am looking at just over 120,000 uf of power supply capacitance at start if I turned on every amp at the same time. (not counting the SW but being class D I doubt it would have much effect) You are at almost four times that amount. It has to have an effect. It would be great if one of the techies would take time to explain what might happen.

Xenon is correct in stating your meter is not necessarily showing everything. My DMM is of the "averaging" type so would not give the actual highs and lows. Shoots my idea of the clamp on amp/voltage meter showing anything we do not know now.

How much current does a class A/B amplifier pull just sitting turned on with no input signal applied? I understand this is relative to the amp but in general. I still think you could solve the problem by bringing the amps up first to get any potential nastiness out of the way before the sensitive stuff comes into play.

It is an interesting puzzle.

Looking around at the DIY sites one of the first upgrades to signal path components is the power supply. I would like to get one of your kills for a bit of fun time and experimentation. Better power supply and film cap/resistor upgrades in the signal path might yield something pretty cool.