Why are most High End Amps class A

Another idea might to get a Plinius SA100, about $1800. They have a switch that goes from AB to pure class A. They put these on the amp to save energy, and then you can flip a switch for "serious" listening. When you flip the switch to class A you start burning 400 watts continuously, nice space heater you have there man.

Most class A amps look to be 25% effecient and have an idle current at 4 times their output. So a 50 watt amp has a 200 watt idle current. The Pass Labs site explains this well. I have not listened to class A, but I think the Plinius could satisfy the curious.

Notice that all Audio Research amps have an idle current at about 4 times rated output, the REF 110 at 100 watts idles at 400 watts, the largest ARC amps like 600 idle at 800 watts. These amps have a really loyal following in terms of their sound, and mixed reviews in terms of reliability.

I have been told that class A amplification simplifies things in that the current is not broken up and then reassembled very fast.

But what does it really sound like? It is expensive and seems to be an audiophile only thing, BEST BUY does not have many class A amps, probably none.

So getting back to Bi-Amping. You could Bi-amp with a low power amp in the mid to get the magic class A sound in the vocal range, and then use SS for bass.

Still another option could be like an ARC VT 50 which is 50 watts and then buy something like a REL powered sub to give you that bass slam. Use the ARC VT 50 with a used set of Maggies to get clarity, transperancy and great mid range and then fill in the bottom with REL. You could do that idea used for $3-4k and have an audiophile set up.

Nice that the Plinius has that switch at least to save on your power bill and energy consumption when desired.

Most of you are thinking of 1 type of class-A power amp - the type that Krell, Plinius, Threshold, Forte, Sugden have made/are making. This type of class-A power amp does dissipate a lot of heat as it is biased to run full power bias current all the time. The heatsinks on these amps are large (they have to be!) & the current draw is high thereby running up your electric bill.
There is another category of class-A amps that use sliding bias. I believe that Symphonic Line & Karan amps (there might be others but I do not know) fall into this category. These amps run cool when there is no signal or when the signal is low (from my experience I would say when the SPL level at the listener's chair ~9-10' away is in the 80dB range). As you crank up the signal input, the dissipation increases markedly. These amps do not run up your electric bill.
Just FYI.

As others have pointed out - a well executed class-AB amp can be very satisfying sonically. I can say this from my own personal experience.
However, [b]THERE IS[/b] a certain sweetness to the sound from a class-A amp. I realize that more when I take out the class-A amp & put back the class-AB amp. It's much easier for me to discern what I lost (when I put the class-AB in) than what I gained (when I put the class-A in). In my particular case I say "lost" because I personally like the sweetness of the class-A sonics. YMMV.

It would be interesting to see how the Symphonic Line ($$$$) vs. a Plinius ($$) would sound side by side. Manual vs automatic transmission.

I wonder if all high bias current amps, or the sliding bias current high current as needed is where that extra sweet audiophile sound is coming from. I am sure it is just part of the mix, but the Plinius looks like one of the least expensive SS choices to get 100 watts of class A power.

When did audiophile's start to worry about the electric bill
There are some great A/B Amps but they are not great because they are less expensive to operate or that they cost less to obtain.
To think that way is to say a Honda is better then a Ferrari
because it gets better gas mileage.
I find Class A amps to sound better then the Class A/B or D that I have heard.
This hobby is about SOUND nothing more and nothing less.