Well... I did a bit of research on the
power consumption specs of several receivers in the price range of under $1,000 street.
Obviously, a receiver can never send the speakers a higher (continuous) total wattage than the wattage it gets from the AC line. So, I figured that the rated AC power consumption of a receiver would likely give us some insights into its "power reserve" and aspects of design philosophy. Of course, this is under the assumption that the manufacturers are fairly honest about the AC power specs (which I guess they must be because of safety regulations). So, here are some results:
Denon AVR-3803: 566W** / 7.0A
H/K AVR-7200: 1040W / 12.9A**
Onkyo TX-SR800: 655W / 8.1A
Pioneer VSX-45TX: 600W / 7.4A**
** Presumptive calculated values based on Onkyo's specs, which list both wattage and amperage (since the power transformer in an amp is not a purely resistive load, you cannot get wattage by simply multiplying amperage by voltage). All amperages are at 120V AC.
Assuming that these listed and calculated values are not grossly different from the real maximum power consumption of these receivers, it is quite interesting to look at these numbers. For example, the Denon appears to have the lowest maximum power consumption, despite the fact that it is rated at 110W x 7 (all others are rated 100W x 7)
and despite its reputation of good power reserve. If these numbers are correct, the Denon cannot possibly feed more than ~560W of total continuous power to the speakers.
H/K's numbers are striking. I also found that this receiver is listed to consume as much as 120W when idle (powered on, but no signal). My guess is that H/K's final stage uses a relatively "shallow" design of Class AB operation (i.e., closer to Class A design, with lots of shunt currents), which
might provide some benefits on sound quality and dynamic power handling. Anyway, no wonder the H/K has a reputation of running quite warm even when idle. By the way, will the 7200 have a cooling fan?
How about the Pioneer? Considering these numbers in conjunction with Pioneer's reputation of also running quite warm (again, probably reflecting a shallow Class AB final-stage design), I would have to agree with some folk's claims of its relatively anemic power reserve.
Just my 2 cents...
