Well some will call their amps Class A, but obviously it's just a marketing tool for some. As you say, "buzz" word.
All 'Class A amps are not equal, just as all Class A/B amps are not equal, and all tube amps are not equal.
FWIW, I have not heard the Karan KA-S 450, but just looking at photos I find it VERY hard to believe that it could be pure Class A. 450 wpc in pure Class A would require monoblocks with much larger heatsinks.
As a comparison, Pass Labs XA series, which runs in pure Class A, goes to monoblocks with their 60 wpc XA-60.5
Their top of the line XA-200.5 puts out 200 wpc, and each monoblock is larger than the stereo Karan 450. So I would be inclined to believe that the Karan slides into Class A/B at around 50 wpc. This is no ding on Karan, as I have not heard this amp. I'm simply saying that physics makes it impossible for me to believe that this amp delivers 450 wpc of Class A power.
It's just physics, Class A generates a LOT of heat. If it truely is Class A, the power rating will be about 20-25% of a similar size amp which slides into A/B. Many amps will give you 5-10 wpc of Class A before sliding into Class A/B, and some may be bold enough to claim that they are Class A amps, as it is a selling feature, and marketing folks know what buzz words attract customers.
I also agree with Ngjockey, that the best way to compare A to A/B is in the same amp. AFAIK, Plinius and Clayton are the only two manufacturers who offer an A>A/B switch that you can flick on the fly. I've owned both, and experimented. I would say the Class A sounded better, more relaxed and articulate especially at low to moderate listening levels. At higher listening levels the differences decreased, IMHO.
Cheers,
John
All 'Class A amps are not equal, just as all Class A/B amps are not equal, and all tube amps are not equal.
FWIW, I have not heard the Karan KA-S 450, but just looking at photos I find it VERY hard to believe that it could be pure Class A. 450 wpc in pure Class A would require monoblocks with much larger heatsinks.
As a comparison, Pass Labs XA series, which runs in pure Class A, goes to monoblocks with their 60 wpc XA-60.5
Their top of the line XA-200.5 puts out 200 wpc, and each monoblock is larger than the stereo Karan 450. So I would be inclined to believe that the Karan slides into Class A/B at around 50 wpc. This is no ding on Karan, as I have not heard this amp. I'm simply saying that physics makes it impossible for me to believe that this amp delivers 450 wpc of Class A power.
It's just physics, Class A generates a LOT of heat. If it truely is Class A, the power rating will be about 20-25% of a similar size amp which slides into A/B. Many amps will give you 5-10 wpc of Class A before sliding into Class A/B, and some may be bold enough to claim that they are Class A amps, as it is a selling feature, and marketing folks know what buzz words attract customers.
I also agree with Ngjockey, that the best way to compare A to A/B is in the same amp. AFAIK, Plinius and Clayton are the only two manufacturers who offer an A>A/B switch that you can flick on the fly. I've owned both, and experimented. I would say the Class A sounded better, more relaxed and articulate especially at low to moderate listening levels. At higher listening levels the differences decreased, IMHO.
Cheers,
John