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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
tom6897's avatar
tom6897
1,484 posts
 
To me the first few watts of class A are the most important. That is where 85%+ of your listening will exist. Only on big crescendos and heavy bass lines will you require more watts. The extra wattage is for headroom when needed. IMO, class A watts are sweet, natural and musical. I could expand further but that would take several paragraphs and I am sure other members will have plenty to say more eloquently than I. I know that I prefer Class A and I own the CODA CSX with 20 watts of class A. 330wpc @8 ohm/660 @4ohm. I real stunner in silver!!!
noromance's avatar
noromance
9,488 posts
 
Class A gets expensive as you go up in watts. Big power supplies and heat sinks because they are biased to run at full power when idle.  
deadhead1000's avatar
deadhead1000
710 posts
 
@Tom6897 is correct on the first few watts. I own the Luxman 590AXII, it was a tough decision to go with pure class A over their 509 with A-AB with more headroom. I do not believe it's hype or marketing. For me, I decided I didn't need more then the 30 watts into 8 ohms or 45 into 4 ohms. I just don't play my music that loud anymore and with 30 watts, I can get well past 90db if I really need too.  I have found it to be plenty of power, but I do still wonder if I could have heard the extra headroom in an AB amp - or perhaps heard the amp when it switches from A to AB (I've heard that some can hear it, some say BS). Just giving you my experience - I doubt I'll ever go back to D amps which I have owned many times.
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