How to spot a high current amps?

Most any amp can provide a high level of "surge current" or momentary "peak to peak" output levels, but it is "long term muscle" that separates the "wanna-be's" from the REAL "brutes". Brief surge capacity can help amps sound cleaner on dynamic peaks, but they may still suffer loss of control / smearing on passages that are both loud and long in duration.

As for the Electron Kinetic's amps, the designer could have easily de-rated the amp to spec at 100 wpc @ 8 and 200 wpc @ 4 ohms. Instead, he chose to rate it more realistically and let the performance of the amp speak for itself. The fact that the Eagles have such large power supplies are what give them a big advantage when it comes to bass control and extended duration low frequency passages i.e. they are able to sustain high current levels longer than many other amps and don't "poop out" easily. Sean
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PS... My favorites are the specs that say something like "2000 watts PMPO" on computer speakers, boom boxes, etc... PMPO translates to "Peak Momentary Power Output" but really means "this is what the device is capable of at the point of thermo-nuclear meltdown" : )

Paulwp-

I'm not saying it's a bad amp. It sounds like it was well engineered for its price point. But that doesn't stop the marketeers.

Your last post sounds like the old "Instantaneous Peak Power" ratings that amps got in the 70's, before the FTC stepped in. You had 1 watt amps delivering 2000 watts of instantaneous peak power.

Refering to my previous post, the power delivered to a load of resistance r with a current of 40 amps is 40^2 times r, or 1600 times r.

So if they claim delivery of 40 amps at 8 ohms, that implies 12,800 watts delivered.

At 4 ohms, that's 6,400 watts.

At 2 ohms, 3200 watts.

At 1 ohm, 1600 watts.

In other words, just saying the amp can deliver 40 amps doesn't really tell you anything by itself. You need to know for how long, into what impedance, and over what bandwidth.

Otherwise it might mean that the amp can deliver 40 amps for just the quarter second it takes for the line fuses to blow, or the protection circuitry to activate.

So does anyone have a rough method of evaluating current without physically contacting the amp. All of the aforementioned techniques are sort of "tire kicking"...

PS - to Dweller

The fuse argument is a good one, but not as you state it. Remember, the amp's power supply converts power line voltage up or down as required by the design (tube or transistor). You can't compare line current directly to speaker current.

So its more correct to say that the fuses limit the continuous power the amp can provide. Power is also equal to voltage times current, so a 10 amp fuse at a line voltage of 115 would limit power to a maximum of 1150 watts.

This number is an upper bound but not a least upper bound, and doesn't take into account efficiency, which would limit power (and thus current) further.

Of course fuses take time to blow, so the instantaneous power drawn from the AC line could exceed this number.

The LFD Mistral SE has no current limiting circuitry. It puts out 75 wpc. Does this mean it's a high current amp? I don't know. To me, if it was a true high current amp it should be able to drive <1 ohm Apogee ribbons and the only limitation would be maximum loudness based on the rated 75 wpc.
Coreymccann there really is no way to know all the facts from a spec sheet. Even if you could find out the amp rating, there are many other problems which you'll never know about. For example, many amps produce high order harmonic frequency distortions which can be incredibly unpleasant. I spoke with a top U.S. amp designer and he mentioned something about thermal stability or intermodulation (Aball is the expert on this stuff) which isn't even measureable but can be audible.
Another way to get high current is with a tube input stage because tubes can handle much higher current peaks than transistors.
I understand your problem because I am having the same problem. You could spend $5,000 trying out all the $2,000 amps out there to find the one that is right for you. So we all have to live in our own fantasy world to some extent and figure what we own is pretty good (or good enough). Or else go broke trying everything in existance.