Class A into Class AB


What is the goal of a designer who makes intergrated amps that have class A for x amount of watts before it goes into class AB? Are there any examples of this being implemented well? I get this feeling that it’s kind of just a marketing thing...where people think they are getting some quality class A without the very high price tag. I was particularly looking at the CODA CSiB amps where you have three choices of how much of your first watts are class A. I have since found a few other respectable brands that implement this as well. I have yet to come across anyone who has heard much of difference between AB amps and one’s that’s state "first X amount of watts..." Class A/AB. Anyone have any experience with these kind of integrated amplifiers? Just looking for a little bit of understanding as I’m trying to upgrade my amplifier.
tmac1700

Showing 1 response by cat_doorman

My (limited) understanding is that class B designates a push/pull configuration with each device (tube, transistor) handling one half cycle. During the transition between devices there is distortion. Class A is always on, drawing the same amount of power regardless of the input signal. Biasing the devices for class A/B helps reduce the transition distortion because there is no longer an abrupt transition between devices. Both devices operate in the transitional region which varies widely between designs.