Gochurchgo,
40 watts best described the class A envelope prior to me ratcheting up the bias of the amp quite a bit. It's currently a nominal 32 watts with a 64 watt class A envelope. Class A amps, especially push-pull, require behemoth power supplies because the amp is drawing full output power from the supply 100% of the time. You never see anything like that in class AB or class D amps. I also removed all of the output current limiting in the amp.
I say these speakers need that quality of power because they're pretty reactive. There's a big difference between 4.1 ohm and 2.8. You can readily crunch the numbers and see what kind of wattage you're speakers are calling for at a given volume and distance. We know they're something like 91dB/2.83V/M. So you figure out the actual listening distance and the required voltage is a square of that number. Then you plug that voltage and the speakers impedance low point into an ohm calculator like you can find online, and it'll tell you the current draw and watts. As long as that wattage is below what the amp will push, you're fine, and that wattage isn't going to be all that high given your speakers.
Hopefully I explained all that right. If I didn't, or it can be explained better, please somebody do so.
I agree with Czbbcl. These folks suggesting triple digit power for those speakers are out of their minds.
