I have a pair of Monitor Audio RS6 for my front speakers. I see that the 7500 is rated at 200 watts at 8 ohms and 300 at 4 ohms. My question is (and will reveal my lack of understanding of impedance loads, perhaps) is, if my speakers are 6 ohms, does this mean the amp will output 250 watts?

I do realize that impedance is not consistent, so maybe my question is too simplistic.

Also, if I'm doing 2 channel listening with the 7500, does that mean there's more available wattage?

First, 250 watts into 6 ohms is about right. It's not going to be quite that high but it will be close.

Listening to two channels will mean that there is incrementally greater power available. Since each channel has its own tap off the transformers, there isn't much that any channel can do to drag down wattage available to any of the other channels.

My mains are 4 ohm, center and surrounds are 8. I can't tell any difference in the mains when driving the center and surrounds.

Makes sense. Thanks for the info.