Originally Posted by jdsmoothie
Depending on the size of your room and how loud you prefer to listen to your 2CH music, the SR7009 on board amps should provide more than enough power. Check this out for yourself before spending extra money on an external amp.
For two channel I agree it should meet the 120W rating just fine without the need for an external amplifier.
Here is a review for the SR7008 and SR7010 models with confirmed measurements:
Marantz SR7008 A/V Receiver Test Bench
2 channels continuously driven, 8 ohms (watts @ 0.1% / 1.0% THD): 122.5 / 148.0
2 channels continuously driven, 4 ohms (watts at 0.1% / 1.0% THD): 195.4 / 216.8
5 channels continuously driven, 8 ohms (watts at 0.1% / 1.0% THD): 101.2 / 111.5
7 channels continuously driven, 8 ohms (watts at 0.1% / 1.0% THD): 68.8 / 82.2
Read more at http://www.soundandvision.com/conten...v390JRVK1kc.99
0.1% THD 1.0% THD
2 Channels Continuously Driven, 8-Ohm Loads 128.7 watts 168.8 watts
2 Channels Continuously Driven, 4-Ohm Loads 201.7 watts 235.3 watts
5 Channels Continuously Driven, 8-Ohm Loads 84.3 watts 113.1 watts
7 Channels Continuously Driven, 8-Ohm Loads 83.2 watts 103.4 watts
Read more at http://www.soundandvision.com/conten...XSaIhtUFZxz.99
I am not sure why the rolloff doesn't occur as fast from 5->7ch in the SR7010 or why they saw more reduction from 2-5ch. The power supplies are listed at 710W for the SR7008/SR7009/SR7010. Perhaps they reduce the voltage rails for the surround channels on the SR7010 when all are enabled or something (purely a guess)...
They didn't have a 9 channel measurement for the SR7010 but I would expect it to drop off with 7->9ch similar to how the SR7008 did from 5-7ch or perhaps a bit more but realistically receivers don't ever have all 9 channels driven in movies anyway...
At any rate if we take the worst of each measurements from the SR7008/SR7010 I would expect the SR7009 to meet them.
External amps are fun but they do add a lot of cost and complexity. For the cost if you do get an external amplifier and you like home theater it might as well be a 5ch because the incremental cost per channel per watt is lower for the 5ch amp vs the stereo amp.
I have gone a bit crazy with external amplifiers and had to break down my equipment for new carpet a few weeks ago and the pile of cables to get 11ch of external amplification was crazy...