Ah so my B&W will still be bright even with rotel paired with the avm?
Absolutely. Unless you can bias your brain to think otherwise.
I don't know about your Anthem pre-pro. But if it has a nice Parametric EQ (like my Yamaha CX-A5100 pre-pro), you can simply manually decrease the amplitude of some of the frequencies in the smallest 0.5dB increments if the sound is too "bright".
For example, you can decrease the 8kHz and 10.1kHz frequencies by 0.5dB or 1.0dB or more. You can easily move it back to 0.0dB if it makes the sound too "warm".
0.0dB is neutral.
Bottom line - audiophile amps usually have a FR of 20Hz-20kHz +/- 0.0dB (usually no more than 0.5dB variance). So they will sound NEUTRAL, not warm (-1.0dB or more) or bright (+1dB or more).
If you want to change the sound to warmer, you need to somehow decrease the amplitude of the upper midrange and treble frequencies.