Originally Posted by kaledii
Are you sure there are no fundamental design changes. Looking at the internal shots of both the SR7011 and SR7010 shows the layout has changed somewhat, particularly around the heat sinks. Looks to be more beafy heat sink with 2? fans directly underneath. Contrast that to the SR7010 heatsink. The transformer looks (possibly) bigger?
I'm particularly interested as I have a SR7009 and a MM8077 driving a 11.2 set up with 8 in ceiling speakers and the normal speakers (for left, right and centre). The SR7011 is driving The surrounds, rear surround and middle height so 6 channels of amplification (the MM8077 driving the remainder). When all speakers are being driven reasonably hard with a Dolby Atmos or upmixed DTS HD + DD track with a volume set no higher than -20db from reference with Dynamic volume off the Sr7009 will invoke the protection circuit and switch itself off. As far as I can tell I don't have a fault with any of the speakers (tested impedance etc). Is this behavior to be expected, or is there potentially a fault with the amp. If as expected, then does this suggest the SR7009 wasn't sufficiently well cooled, or powered; have Marantz changed the design to improve this with the SR7011?
When your 7009 went into protection mode, how fast was the standby light blinking?
If it blinks several times/second, then it's an amp-related problem.
What model of surround and overhead speakers do you have?
If there isn't a defect in the receivers internal amps, this might be due to "difficult to drive speakers".
How did you test the impedance?
You can't just use an ohm meter, since Ohm meters only test DC and speakers have a varying impedance which is different at different frequencies.
If the blink is slow, with several seconds per blink, then it's an overheating problem (usually caused by being in an enclosure) and you need to enable ECO mode and/or add an external fan.