Are There Any Inherent Advantages to Class A amps?


All things being equal, power supply size, wpc into 2 ohms and everything else, Is a class A design inherently better than an A/B design? Disregarding the heat issue with class A amps, what makes them so desirable?

I'm saving my money for a pair of used serious monoblocs. I'm thinking a pair of used Pass X-600 monos or a pair of used Krell 750 monos. On the used market, the Krells are approx twice the cost of the Pass monos.

The Krells are pure class A, the Pass are class A for the first 160 watts, then they go to A/B.
128x128mitch4t
I don't think the class of operation will (or should) make one amp be more advantageous over another. To answer the question directly: yes, there is an inherent advantage. It's the elimination of cross over distortion which means one less level of distortion to worry about during design. If one were to design a cost-not-matters sota amp, then class A will probably be ONE design criterion.

But it doesn't mean that the advantage results in a better amplifier - too many other factors are involved. I personally prefer the class A/B Classe amps over the class A Krells. Nothing against Krell, but to me their amps are just not to my taste. So to toss the coin with an eye towards operating class will not, in my view, bring about the end result of a good sounding system.
"The Krell is probobly [SIC] pure class a for the first few watts or so."

That's class AB, Radiob.

Mitch, I believe class-A-biased amps have an inherent sound-quality advantage over class-AB-biased amps, but in well-designed amps, this advantage is overwhelmed...swamped...by other differences. Buy according to the usual criteria...

Class-A amps do make great room heaters! :-)
Dear Mitch4t: Switching-cross distortion: as a fact almost every amplifier works in class AB, what this means?: that it works in class A, for a few or severals watts, and in some time switch to works in class B. So, there are amplifiers that works the first 5, 10, 50, 100 watts in class A and when you are asking for more ( watts ) switch to class B.
This switching-cross distortion ( up and down ) it can be audible. So, a pure class A amplifier does not have this switching distortion because always is working in class A and this is the inherent advantage of pure class A. Theoricaletly the class A has less distortion than class B ( it can be measured ) but it is almost inaudible ( in good designed amplifiers ) , example: if you have two amplifiers ( that have same specifications, design and designer ), one pure class A and one pure class B, working between their best linear power ( not near clipping point ) it is almost immposible to detect any differences in the quality of the sound reproduction .
BTW, I don't know why you need the Krells 750 or the Pass XA 600 in an audio system where your front loudspeakers are biamplified. Can you explain this?
Regards and always enjoy the music.
Raul.
Gs, I generally agree. I stopped short of recommending that Mitch should go for the Class A because there are simply too many design characteristics that influence overall sound. There are clearly A/B designs that beat A designs -- that was also made fairly clear in the great references shared by Tripper. On a straight design to design comparison (i.e., same amp), Class A rules. As always, judge with your ears. Good point Gs.
Raul, I'm considering the Krell and Pass monoblocs to upgrade from my current amplifiers. My current amps are the Carver Silver 9t monoblocs, they are/were the price point that I was able to attempt to enter into the high end audio arena. I started with one pair and I liked the sound, I got another pair and bi-amped, then a whole new world opened up. Then I got the AR LS-10 preamp and the system took another quantum leap. I recognize that my current amps do not rank high on the heap of hifi, some even consider them mid-fi. So, the reason that I'm considering the Krell and Pass monoblocs is to see if they take my system to another dimension. My Infinity Kappa 9 speakers dip to really low impedances and I want unquestioned authority on the bottom end....I keep hearing Krell is really strong there. I tried using a Sunfire Signature on the bottom while bi-amping, and while good, it did not deliver the slam and control that the Carver monoblocs delivered.

My Carver monoblocs cost $1500 per pair used. The Krells will be at least $15k used, whereas the Pass will be about $8k used. I hear that the Pass and Krell monoblocs are light years better my Carver monoblocs. What kind of performance leap can I expect by upgrading to the Pass or Krells? I prefer to bi-amp with matching amps, but at those prices, that will be prohibitive for now.

I liked the sound of my system at every point before I upgraded it, and I liked it better than before every time I upgraded.

I plan to spend no more than $1k for speaker cable and interconnects for the entire system.

Any of you, please weigh in on this for me.

thanks....mitch