So here's what I've got...
The 2-channel Rotel is the RB-980BX rated at 120 watts per channel.
The 6-channel Rotel is the RB-956AX rated at 40 watts per channel.
RSP980 Brochure.pdf (rotel.com)
The Audiosource is an AMP200 rated at 80 watts per channel
Finally, I have an Audio Design Associates MPA-6. I couldn't find much other than it's 100 watts per channel.