Did you read the article linked in the first post of this thread? The Sony avr just says power consumption, not max, and can exceed 240W.
That was a pretty useless response. Thanks. For example, why would Sony elect to mark it as a 240 watt device when it could potentially draw more, even when tested at 1/8 de-rated, unclipped power. Since Sony advertises 120 watts per channel at 1 kHz, it looks to me that the formula would work out to be:
Class AB: 0.125 * 120 = 15 watts / .20 (eff) = 75 watts x 7 = 525 watts
So again, why did Sony elect to mark this as a 240 watt input device. when, from a marketing perspective, a bigger number would look better, and from an electrical load perspective, at 1/8 load, ACD, this AVR would draw quite a lot more than 240 watts... unless there is some sort of thermal protection built in which limits the output power.
And again, for the JBL MA710, the formula looks like this:
Class D: 0.125*110 = 13.75 watts / .80 (eff) = 17.19 watts x 7 = 120.32 watts
So why did JBL mark the this as a 500 MAX watt device? Does this number suggest that as one approaches max power and 90 percent efficiency, this AVR could potentially (by the numbers given) put out as much as 55 percent of rated power, ACD, as in:
Class D: 0.55*110 = 60.5 watts / .90 (eff) = 67.2 watts x 7 = 470.6 watts
I doubt that's actually the case; nevertheless, the MAX input power of this device was derived from somewhere, and based upon the output power alone, 500 seems excessive.
Perhaps you could enlighten us?