Krell Amps vs others

Be careful throwing around the "class A" terminology as nearly all amps that flaunt Class A status are only so for the first tens of Watts (even a hundred is rare), not for the full 500W or what. A 500W class A output would burn up 2500 to 3000W which is a tough thermal challenge. Generally class A refers to the fact that the BIAS is class A, and not operation at full power. Actually nearly all audio amps could be called class A amps. It is just that the class A upper limit changes making some more class A than others (e.g., some go AB at 50mW and some at 50W).

I also meant to add that the new Pass XA series is surely worth looking into (and the other Pass for that matter). Arthur

Pettyfeversk: Your Dynaudio's will take a million watts if you can feed it to them. So long as you keep the quality level of the power that they are being fed up to a high level, the more power that you can feed them, the better they will sound. Welcome to the world of "phenomenally thirsty" speakers. My guess is that about 800 - 1200 wpc should do it. Obviously, this will depend on the size of the listening room, type of music and the spl's that you want to achieve with good clarity.

John: I like your thinking. I too "love" the SA12's. I had a chance to buy a pair a while back for a very fair price and passed it up. I am kicking myself on a regular basis over this one. Out of all of the deals that i've passed up, this is the one that haunts me. Having said that, I'd like to see how the 12's stack up to the newer X amps in a side by side. Regardless of which one would "win", it would be quite fun and interesting to say the least : )

Art: Your right on the money. I wonder what amp is actually biased and operates in Class A the longest ( highest power ) ??? Bare in mind that as you drop impedance, your ability to remain in Class A also drops. I know that Bear's amp, which is a MONSTER ( or is it a "bear" : ) in terms of sheer weight, runs in pure Class A up to 50 watts. Anybody know of anything that beats that ? I know that a lot of amps say "Class A", but i sincerely doubt that they operate up to the levels claimed in Class A. Sean
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Check out Edge and Boulder, as well. These also offer a variable bias approach, somewhat akin to Krell, but implemented differently if I'm not mistaken. Class A operation is maintained by ensuring the bias point is high enough relative to the signal level to prevent signal distortion or class AB operation. This greatly improves amplifier efficiency, but at what sonic cost? None? A little? A lot? Listen for yourself and decide. Good luck.

As above, regarding "clas A" & how much of it we really get.

Other than Bear's Symphony1, another amp that runs in A for a long time is the Symphonic Line Kraft 250 (stereo & monos: the latter offer ~250 A instantaneous @ peaks). BUT, like Bear's amp, they are huge and heavy (+150pds each), and UNLIKE Bear's amp, they are ugly. But they produce prodigious bass and natural harmonics in the upper end...