I do notice when it goes off line...the fan slows down (to about 80% power I guess) and then resumes.
Ouch! That doesn't sound right. I've never heard my power supply fan slow down like that.
Four possibilities come to mind:
(1) Voltage dropout from the wall socket. But if you observe the symptom happening only when a heater is turned on, that's probably not it. (And a good UPS should prevent this.)
(2) Problem with the power supply.
(3) Problem with the Azteeg controller.
(4) A heater is drawing way too much current.
Try this: Unplug printer from wall, and unplug USB cable too, wait for a minute, then measure the resistance of each heater element. Measure at the Azteeg, right at the screw terminals (you don't have to disconnect the wires): H-BED, H-END1, H-END2 (if you have both).
My Helios platform heater measures 1.3 ohms, and my hot ends are about 7.6 ohms each.
Try this too: Measure platform heater with one hand while you move the platform back and forth with the other. Then measure hot end heater while moving the X carriage back and forth. You shouldn't observe the resistance changing while you are moving the carriage; if you do, perhaps there is an intermittent short happening while the cable is flexing. (A long shot perhaps, but a good thing to rule out...)
A dead short happening in a heater circuit would be a bad thing, and might explain what you are observing.