Amplifier power ratings and distortion.
I had a Crown CE1000 and due to weight was looking at changing it to an XLS1502. The CE1000 was rated at 275 W/ch into 8 ohms. The XLS1502 is rated at 300 W/ch into 8 ohms. You would think that was a good substitute. However I note the CE1000 was 275W at 0.1% distortion and the XLS 1502 was at 0.5% distortion. So if you measured the XLS 1502 at 0.1% distortion what would the power rating be? My observation of power versus distortion is when you start to drive the amplifier into distortion the distortion increases quite rapidly with a minor increase in power. Also on power rating, what does maximum continuous power really mean? Is it close to the RMS rating. My observations are the XLS 1502 does not seem as powerful as CE1000. The CE1000 feels like it has more reserve power and sounds a bit sweeter in the high frequencies. That may be just the Class D versus AB but it is compared using the same speakers.
Don't get me wrong, I think the XLS 1502 is a great amplifier in many ways. The modern class D offers some big pluses.
I'd be interested in other peoples experiences.
Rated distortion figures, at these rated power are hardly audible. Don't forget that these figures are usually determined with a sine wave at rated power! Do we usually work with sine waves? Usually, no.
Notable difference between a CE and XLS02 series is the power supply. CE has a transformer, analog type psu, while the XLS is SMPS driven. The CE has classic AB output configuration while the XLS has a D style configuration, using a sophistically engineered IC for drive!
IMO, the CE has more low freq impact (warmth) compared to the XLS's precision (hf) but sterile