Did you mean to say that only Marantz and Yamaha provide AVRs that are adequate for 2 channel music listening? The OP is looking for the best home theater receiver based on its 2 channel music performance.
"Any" top of the line AVR from "Any" major vendor will push more than enough of power to stereo speakers. If they don't push enough power for enjoyment. I want those speakers.
My CV SL-15s in stereo on the 8015 enjoy the experience. I can hit the ceiling on my setup of maximum quality sound when I try to push it, the problem if you can call it that, is I can only to listen to it for 5 to 10 minutes without ear protection. Again I regret nothing.
Hard to say the volume at the time. For it differs depending on speakers used, filters set or changes to the center channel.
Roughly i'd say it gets to about 50% power usage before I need to dial it back.
If i had to guess, its somewhere between -20 to +3 on the volume dial side, depending on the source, type, etc. It's a wide range for dial settings I know, roughly most of the time 80% -15 / to -8. +3 center. Ecomode off.
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My setup 8015, 3x SL-15, 2x SL-12s, 2x SL-8s.
Caveat I do listen to it mostly in 7.0.
If the OP heard what happens when you put those speakers in extended stereo mode, I wouldn't need to explain my argument.
You could set the speakers in "stereo" placement around the TV and turn it on. It's just as fxcking deadly as "surround mode" or as I imagine atmos is as well.
I still stand by my point, get whichever brand, my preference is Marantz, their top of the line options firstly, second but it could be a coin toss, the top of the line Yamaha.
I see some want the denon clone. It's likely the close to the same effect as the marantz. The torrodial thingy, does help.