Why are most High End Amps class A

Consider Bi-Amping. Use a calss A tube amp for the mid-range to get warmth / big sound stage, and use solid state in the bass for impact.

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.

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.

Kirkus,

We touched on Bi-amping a bit and using class "A" on the high frequency, and class A/B on the bass. I noticed on a system you helped create you used a Marantz Model 2 with EL34 tubes for high frequency and then a McIntosh MC275 with KT88 for the low frequency.

Is the Marantz running in class A, or do you like the mix of a nice EL34 amp for the high frequency and then the KT88 for the low frequency.

How can you bi-amp economically to try and get nice high notes, leads, vocals, and then get good bass as well. If you bi-amp should you stick to all tubes, or all SS or can you mix it?

So Kirkus,

What AMPS do you like and why if it does not matter if they are class A or class AB? Do you judge an amp mostly subjectively by sound or do you look for a particular construction?

It seems like you are a real expert in this area.

The wine analogy that Kirkus used might be the way to go here, but with wine the you can try many types easily and see what you like and have a collection of Cabernet, Pinot, Chardonnay, etc.

But with Hi-Fi, you can't collect to the same degree, and you cannot sample to the same degree. So I think for many people we rely on the audio equipment equivalent of the master sommelier, like reviews from Stereophile as stated above or sound engineers with a lot of experience and people who have been into it for a long time. The expense of audio, and the rate of audio collection, generate a reliance on expert advice in this kind of situation.

So what is the advice for the guy who started this thread, he likes his McIntosh gear. What would be an interesting flavor change, would a Plinius SA100 mkIII be an interesting taste choice? Better is pretty subjective, but how would a class A amp with his McIntosh pre be different?