Help me understand Amps

[Doug Lax]

I understand that class A amps usually double down when the impedance is lower. I driving a lower impedance harder on the amps ? How does effiency play into it?

[Amfibius]

Hi Douglax, a sign of a good amp (not just Class A) is that it doubles its power when the impedance is halved.

Yes, lower impedance is harder on amps, because it has to produce twice the current (or voltage, depending on what type of amp it is).

Efficiency is an independent variable.

[Volks]

Originally Posted by Amfibius

Hi Douglax, a sign of a good amp (not just Class A) is that it doubles its power when the impedance is halved.

Yes, lower impedance is harder on amps, because it has to produce twice the current (or voltage, depending on what type of amp it is).

Efficiency is an independent variable.

But what about Mcintosh?It does not double the power when the impedance drops and of course they are still good amps......i guess what im saying is.......If the impedance is halved and the amp doubles its power.....is that really a sign of a "Good Amp" or is it just how it does its job?

[Hawk]

McIntosh uses autoformers to keep the power consistent regardless of the speaker. Here is an answer from McIntosh concerning a question I had about this:


"Some brands just burn out 10 min after the warranty is up.
On a Krell 100 watt amp, it does 100 into 8ohms, 200 into 4 ohms and 400 into 2 ohms, they do this by making the power supply and heatsinks good for 400 watts, but if you have 8 ohm speakers, get 100 watts, but you PAY for a 400 watt amp! That’s why we say with autoformers, you get all the power you pay for."

Chuck Hinton of McIntosh & Snell Tech Support

[Doug Lax]

Originally Posted by Amfibius

Hi Douglax, a sign of a good amp (not just Class A) is that it doubles its power when the impedance is halved.

Yes, lower impedance is harder on amps, because it has to produce twice the current (or voltage, depending on what type of amp it is).

Efficiency is an independent variable.

Thanks Amfibius does the stability of the amp suffer then?

[10Beers]

I hope this helps..http://http://www.passlabs.com/pdfs/...ng_class_a.pdf