2. amps-preamps
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Watts and power

Can somebody break it down in layman's terms for me? Why is it that sometimes an amp that has a high watt rating (like, say, a lot of class D amps do) don't seem to always have the balls that much lower rated A or AB amps do? I have heard some people say, "It's not the watts, it's the power supply." Are they talking about big honkin' toroidal transformers? I know opinions vary on a speaker like, say, Magnepans - Maggies love power, right? A lot of people caution against using class D amps to drive them and then will turn around and say that a receiver like the Outlaw RR2160 (rated at 110 watts into 8 ohms) drives Maggies really well! I'm not really asking about differences between Class D, A, or AB so much as I am asking about how can you tell the POWER an amp has from the specs? 
redstarwraith

Showing 1 response by drasberry

drasberry
3 posts
 
The difference in acoustic power delivery between amplifiers regardless of design class eventually comes down to the maximum instantaneous peak voltage the power supply can deliver relative to its RMS average power rating. 
Music can demand peak to average power ratios as high as 10 times or more the average output.
Class D amps are limited to the maximum rail voltage of the power supply.  A more traditional power supply with large transformers and very high capacity filter caps can potentially deliver several times the rail voltage on peak demand as the caps discharge before hitting clipping.So an amplifier with deep voltage and current reserves beyond it's nominal rating can deliver higher average power in relation to peak demands than one with a lesser power supply of the same rating.
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