Behringer NU6000DSP iNUKE - How does it make rated power claims with 15A receptacle?

[krips]

I'm wondering how power amps make this much power while running off what seems to be a standard power cord? This one in particular claims to put out 4400w at 4ohms with what appears to be a 15a cord running to it? To me this would require around 36 amps to do, so a 50A cord and #8 wire or better would be needed. Thanks .

[wkhanna]

manufactures (but not all) often take 'best case' scenarios when publishing specs.
power ratings are often given for instantaneous performance (over a V short period time).
the transformers & capacitors in amps also can allow for short bursts of power depending on the design.

this is a V non-technical reply, others are welcome to go to further length in answering krips' question.

[JonMarsh]

There has to be sufficient energy storage in the capacitors in the powe supply to deliver that current- you're quite right, in that a normal 15 or 20A 115VAC line won't do it. This Class D amp uses a switch mode power supply, and energy storage could be done both at the output rails, and at the rectified bulk AC DC rail- and energy storage is proportional to the capacitance,but to the square of the voltage. That said, the 3 kW at 4 ohms is strictly a transient rating, based on the fact that music has a typical crest to average ratio of 6:1. So, the continuous power capability is likely 1/6 or less- in fact, if I could read the back panel illustration (at Sweetwater) a bit more clearly, I think it just says 625w. So Behringer may be working on a 10-1 ratio of peak to continuous power. Peak power will be set by the power supply voltage rails and how much energy the caps can store without sagging excessively. BTW, amps with a lot of rail sag don't usually sound very good. Note, this is really intended as a live performance PA amplifier, not for a home music system.