switching between two amplifiers; issues of power

Well, mr decibel is one who’s input I trust for sure. We don’t run an hour in the high nineties for many reasons... this isn’t a lecture but watch your ears !!!! Royals is a high power density track ( give me a bit and I will post the RTA of that track on my virtual system page - I was recently using that to help a fellow audiogon member size his amplifier ( with less efficient speakers than yours )
your hour requirement drives duty cycle. In an A/B amp, you need a beefy power supply, lots of output devices and a way to get the heat out. Look under the hood on the 225 and it will indeed be lacking, so I retract my recommendation. I would point you to Van Alstine IF the class D disappoints. I will let you know when I put up the RTA photo - it is a great track for taxing a system.

Yes, my use of high nineties was for projection out of windows into my backyard. With alleged 98db speakers, I didn't think this would be a problem (for the Nuforce), but it did heat up (considerably) over the hour... 

Within the 12x14.5 room of primary listenership, Peaks are more in the high eighties, or lower, for most of my listening. I should try Royals in that context, but truth-be-told, I'm fairly tired of the song. It's more a sonic biceps flex than anything else.

Just received Trio Jeepy CD from the culture of Amazon, and the hints of the original space of recording come through. Love the distance-impression of the sax, out on the left, the chunky and springy percussion off the right, the sweet double-bass in the midst. The Nuforce is perfect for this. 

I'd be interested to learn more about how the RTA of Royals interacts with an amp. 

@tomic601 You mention, "Van Alstine IF the class D disappoints." I did a search, nothing came up that matched... 

Try Audio by Van Alstine

OK I posted the screenshot of RTA with Royals. A fun track for sure to flex the bass a bit. You can find it on my virtual system Poverty Bay Sound. Have fun, i hope your search is going well.
Jim

Hello Listening99.  Power is a funny thing. The numbers don't fit into our brains very well.  If you've watched Vu meters while music is playing, you know a 10 db jump is not all that impressive. The loudness difference between 1/10 of a watt and 1 watt is the same difference as between 80 watts and 800 watts! So 300 watts is not nearly four times louder than 80 watts. It's just under 6 db louder. 320 watts would be 6 db louder than 80 watts. So it's NOT a matter of perceivable loudness, it's a matter of the apparent ease of an hi wattage amp not running out of power and clipping at say, 200 watts when an 80 watter would have run our of power and clipped the wave, which sounds bad. A current hungry speaker (low impedance) is going to tax any amp, so it's good to have one that can deliver the goods when needed. Good luck with the new amps they will play cleaner at volumes where the 80 watter was struggling. Place them where they can have plenty of ventilation. Keep Smiling!