[perpetual]

I posted this as a response in a thread but only got one answer.


I've been wondering something about amps. I'm planning to buy one in the near future, probably used since I don't have that much of a budget.


I've been looking at different amps and see a vast difference in weight between amps, even if they have the same power. for example the emotiva xpa 5 is 200wpc and only weights around 60lbs. some of the amps I'm considering are also 200wpc but weight close to 100lbs or more. some even come with two power cables to use two outlets. some of these amps also have 1.5k power transformers or more and 130,000 capacitance and still are only rated at 200wpc.


my question is why the vast difference and which would be better?



also, are ATI amps any good? how do they compare to the emotiva amps.


thanks.

 

[RoboRay]

One thing to be aware of is that published amp power ratings have very little meaning. There is no agreed-upon standard way to measure, and every company does it differently. Some companies even measure their different models in different ways!


In general, it's often fairly safe to say that a heavier amp is more honest about it's power claims than a featherweight one, but even that's not entirely true. And cool-running Class-D amps throw that assumption entirely out the window, as they simply don't need the heavy heat sinks of less efficient amp designs.


You can use the published power spec as a starting point for determining an amp's true capabilities, but you really have to check all the details... Was it rated with a full-range signal or just a 1kHz test tone? Was it rated at .05% THD, .1% THD, 1% THD, or 10% THD? For a multi-channel amp, was it rated with all channels driven, or with only two in use, or even just one?


Unfortunately, there are so many variables to amplifier power rating amplifiers that comparing the simple wattage number is pretty much pointless.


As far as signal quality goes... So long as your amp has sufficient power available to produce the sound levels you desire without clipping and distorting, there will be no audible difference with any other modern amp that's not clipping.