I went from Class D to Luxman A/AB - And most of what you think is wrong


Hi everyone,

As most of you know, I’m a fan of Class D. I have lived with ICEPower 250AS based amps for a couple of years. Before that I lived with a pair of Parasound A21s (for HT) and now I’m listening to a Luxman 507ux.


I have some thoughts after long term listening:
  • The tropes of Class D having particularly bad, noticeable Class D qualities are all wrong and have been for years.
  • No one has ever heard my Class D amps and gone: "Oh, wow, Class D, that’s why I hate it."
  • The Luxman is a better amp than my ICEPower modules, which are already pretty old.

I found the Class D a touch warm, powerful, noise free. Blindfolded I cannot tell them apart from the Parasound A21s which are completely linear, and run a touch warm due to high Class A operation, and VERY similar in power output.


The Luxman 507 beats them both, but no amp stands out as nasty sounding or lacking in the ability to be musical and involving.


What the Luxman 507 does better is in the midrange and ends of the spectrum. It is less dark, sweeter in the midrange, and sounds more powerful, almost "louder" in the sense of having more treble and bass. It IS a better amplifier than I had before. Imaging is about the same.


There was one significant operational difference, which others have confirmed. I don't know why this is true, but the Class D amps needed 2-4 days to warm up. The Luxman needs no time at all. I have no rational, engineering explanation for this. After leaving the ICEPower amps off for a weekend, they sounded pretty low fi. Took 2 days to come back. I can come home after work and turn the Luxman on and it sounds great from the first moment.


Please keep this in mind when evaluating.


Best,

E
erik_squires
They are an entirely analog process.
 
And for the most part in the nCore/ICEpower/Pascal/TI world this is true, though recent amplifiers from Technics blur the line further, with an A/D stage, DSP processing and unknown amounts of analog feedback at the outputs.
@jmolsberg, suggest trying to get a listen to some of the following class D amp brands, SPEC, Audio Nec and Mola Mola, that might change your mind.
And for the most part in the nCore/ICEpower/Pascal/TI world this is true, though recent amplifiers from Technics blur the line further, with an A/D stage, DSP processing and unknown amounts of analog feedback at the outputs.
Yes, that does add to the confusion. But even with an digital source built into the amp, its still an analog process.
But even with an digital source built into the amp, its still an analog process.

There are people who are going to argue all audio amplifiers are by definition, analog, but we don’t call DAC’s analog either.

If an amp samples the input into discrete voltages, at regular intervals (i.e. has a sampling rate) and has an output controlled by those inputs, even if the last stage has an analog feedback loop, then it is 95% digital, and the last part had an analog feedback loop I call bunk on those who want to insist that makes the whole amp analog.  Calling it a digital amplifier is a lot closer to the truth than calling an analog amp.


Best,
E
Calling it a digital amplifier is a lot closer to the truth than calling an analog amp.
Amplification process is still analog, hence "Analog Amplifier".  Connecting amplifier to DAC doesn't make amplification "digital".