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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
mapman's avatar
mapman
22,288 posts
 
Your experience is your experience as mine is mine and others are theirs. I’m saying yours is possible despite mine for many possible reasons. Please don’t say others aren’t because of yours, especially when there are specs and measurements in many cases to support specific claims like high current delivery with specific models/designs.

High efficiency obviously is a factor that helps enable high current delivery capabilities, not hinder it.

As for George, with all due respect, his comments regarding Class D seem based largely on theory, not on practical experience. Maybe I missed something?
golfnutz
231 posts
 
All I'm saying is what George is describing has been my exact experience. There is no way the 1200as2 is a high current amp putting out 600w (8ohms) or 1200w (4ohms). It might do well with efficient speakers, but it does not do well with inefficient speakers.
mapman's avatar
mapman
22,288 posts
 
IS 1200as2 the IcePower module? What amps specifically are you referring to that use it?


The overall design matters. For example a Bel Canto ref1000 (older ice module in a nice box) is not the same as a ref1000m which is same ice module + custom input section and power supply in similar nice box. Both are spec’ed at 500w/ch into 8 ohm. The ref1000m’s are the only amp I have ever owned capable of driving any speaker I throw at them to their max and never ever even comes close to breaking a sweat. The sound is smooth, non-fatiguing and totally effortless at any practical volume, another first experienced for me.

So any claim that Class D can’t do that is totally wrong. As is anyone who might claim any Class D can.

Even the TI Class D module in my $85 Fosi amp is capable of more if integrated and housed towards that end where the extra heat generated is able to dissipate.

The devil is always in the details, Class D or otherwise. Avoid drawing generalized conclusions from limited evidence much less on theory alone.




golfnutz
231 posts
 
Yes, the 1200as2 is the Icepower module. By no means am I bashing class D. All I am saying is that this module does not do well with inefficient speakers (watt/puppy). I also have Pass Labs amp, and the comparisons are night and day (not even close). When I initially purchased the 1200as2, I wanted to use them for Home Theatre, but decided it wasn't the way to go. I had 2 of these amps and was going to get a third, but I made the decision to just keep my 5 channel Parasound amp.
mapman's avatar
mapman
22,288 posts
 
Are you building your own amp using that module?  If not what specific amp using that module are you talking about?   Sorry if I missed that.


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