You could be driving each of your speakers with just 10 watts, and have your room filled with sound in low 90dB area. Can you play much louder than that in your apartment? I too thought you already had the 770.

When you say class A power (100 watts), what is that? Does that amp work in a purely class A mode below 100 watts? If that is the case then its idle current draw would be very high?

I really think you can run all your mono blocks on the same circuit as long as you are not running all of them at high power levels i.e. 100 watts to all channels at the same time.

The only other issue I could see is if the mono blocks are triggered on at the same time. If they do not have a soft-start circuit in the power supply, the surge of current pulled from the outlet to charge caps can trip circuit breakers. One or two amps might not be a problem, but six at the same time might be.