The only potential for damage that i see would be one of a safety factor to you, the human being using the device. so long as the amp never "goes defective" on you, i don't see that coming into play either. Sean
Classe knows better than to assume that everyone has three-wire wiring in the house. It's unlikely that the third prong of the AC Mains cord for requied for anything necessary to the functioning of the amplifier . . . though there might be some kind of AC Mains filtering in the amp that uses the AC ground as a place to dump noise. Check with Classe on that.
Typically the third prong is a safety ground only, a path for current to take in the event that the product suffers an internal failure that might otherwise cause the chassis to become "live" and zap ya. Classe builds good stuff -- you can certainly float the plug without affecting the operation of the amp.
But for safety, I always recommend that one (and only one) component get grounded. Ground more than one component and you'll probably create a ground loop, which can cause audible speaker hum. BTW, systems that are fully-balanced, i.e., which use balanced interconnects, can have more than one component grounded without worry about ground loop-induced hums 'n' buzzes.
I'm in an older building and have to float all my grounds as I've only got 2-prong outlets. Since I recently started using a high-end power strip I've been getting shocks that feel like pins & needles when I unhook positive RCA connections from my preamp and sometimes my DAC(volume is down and amp is turned off). Nothing fatal but is this potentially harmful to me or my equipment? Should I unplug everything when I change connections? Sorry to diverge from the main question but it seems related. Thanks.
Tim please follow Seans' advice you may have a potentially lethal situation there. I presently ground all of my stuff, but I wouldn't hesitate to lift grounds as required to eliminate hum that can't be cured in any other way. Just always be well aware of the 'potential' for personal harm, which in your case does definitely exist; BE CAREFUL! If you measure with a voltmeter between those 'tingling connections' you'll probably read something close to 100 volts. Try reversing some AC plugs while trying not to induce any hum. If that doesn't help then try an inexpensive isolation transformer like Francisco uses; do a search for membername = Psychicanimal; he has posted on the subject.