What are the most powerful Pure Class A Amplifiers ever made?

LL21

Well-Known Member
Dec 26, 2010
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Very cool...thanks Wizard.
 

MylesBAstor

Well-Known Member
Apr 20, 2010
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New York City
PA460m inside.

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I read a review of PA460 stereo - this is just paper watts - in real life it can deliver only in 8/4 ohms 110/130 watt with 1,5% distortion.
It can deliver up to 8A peak current in 3,5 ohms - this is a weak amplifier.

And Slew rate was very slow at only 6V.

Shouldn't Class A double down? :) Paperweight?
 

audioarcher

Well-Known Member
May 6, 2012
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Seattle area
^^ The ability to double power as the load is cut in half has nothing to do with the amp being class A.

Is there any amp that truly does double it's power as the loading is cut in half? Some manufacturers that claim their amps can are just under rating their power into 8 ohms so it appears that it doubles into 4 ohms.
 

mep

Member Sponsor & WBF Founding Member
Apr 20, 2010
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Is there any amp that truly does double it's power as the loading is cut in half? Some manufacturers that claim their amps can are just under rating their power into 8 ohms so it appears that it doubles into 4 ohms.

Ok. So pick an output power number that a manufacturer gives for 8 ohms and see if the output power keeps doubling down even past the 4 ohm mark. Maybe that will tell you more about the power supply. My KSA-250 is 250 watts into 8 ohms and 4000 watts into .5 ohms. If you drop your 8 ohm rating down low enough so that the power appears to double into 4 ohms, I think it will run into a problem as the impedance drops in order to maintain that doubling of power. You can fudge the first output power number in order to make the second appear 'right,' but the charade won't continue.
 

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