dmb12679 Posted January 12, 2018 Share Posted January 12, 2018 Put the ear plugs in and the dog in the laundry room and played with my HK990 and rf7ii's for a short while today. Had a kill-o-watt I've been meaning to see what my system is actually drawing. I plugged the panamax into the Meter, and the Meter into a 1' extension cord into the wall outlet. I know this equipment is far from perfect, but I was just curious as to about what it would pull. The HK990, HD990 cd player, and AC T8 on idle pulled abut 220 watts. 200 watts alone for the HK990. Yikes I sit 14' from the rf7ii's for my db max on my iPhone decibel X ap doing readings. This room has 18' ceilings and is open all around it. Idle draw 215-220 watts Vol -35 av watts 220-225, peak 225, 81db peak Vol -10 av watts 300-305, peak 345, 106db peak Vol 0 av watts 460-470, peak 750 111db peak My HK goes to +10, but didn't think it was a good idea to go any louder. In bench tests it hit 200wpc@8ohm, and double down 400wpc at 4ohm If the HK draws 200 watts on idle, does that mean at my peak of 750 watts, 750-220(idle watts) 530 watts Divided by 2 channels = 265 wpc into the 7ii's?? I know the doubling of power, gain 3db standard, but what about in a real world setting listening to Money for Nothing, that was my CD that was playing It was extremely loud Any opinions? Anyone have a better way of measuring or done something similar? Might try and do the same with my Marantz Home theater set up tomorrow watching Fury Road I know the methods and measurements here are not accurate, but they have to be ballpark ideas. The HK should bottom out at 200wpc@8ohm, so did the ohm dip to 6-4 to allow for more wattage? Or are my measurements that off? Quote Link to comment Share on other sites More sharing options...
Don Richard Posted January 17, 2018 Share Posted January 17, 2018 Current draw from the wall socket will not scale linearly when Class A/B amplifiers go from Class A into class B operation. An amplifier operating in pure Class A wouldn't vary AC power draw much at all. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted January 17, 2018 Share Posted January 17, 2018 1 hour ago, Don Richard said: An amplifier operating in pure Class A wouldn't vary AC power draw much at all. Just the amount of heat it gives off? Quote Link to comment Share on other sites More sharing options...
dmb12679 Posted January 22, 2018 Author Share Posted January 22, 2018 So when I see the initial 210 watts when I turn it on, with no signal being sent, that is the steady ac power draw of the class A? I haven't been able to find anything on when the 990 will/supposed to switch from a to b. Quote Link to comment Share on other sites More sharing options...
dmb12679 Posted January 22, 2018 Author Share Posted January 22, 2018 When I was playing I was hitting peaks of 750 watts, but steady at 210 with nothing playing. So it did affect the draw from the wall outlet. I tried it at 3 different volume levels and they varied with each in relation, but definitely not fairly consistent from the wall. I'm not worried about it, just trying to understand it better. I also found that my spl app on my iPhone is highly inaccurate, especially on the higher DB's. I was well beyond 111, but that is what I logged while doing my experiment. Quote Link to comment Share on other sites More sharing options...
babadono Posted January 22, 2018 Share Posted January 22, 2018 From Dr. Obvious: Amplifiers are not 100% efficient. That is they do not change all the power drawn from the wall socket into power out to your speakers. Hence they get warm. Some amps are more efficient than others. Quote Link to comment Share on other sites More sharing options...
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