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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
toetapaudio
474 posts
 
So, @georgehifi you have compared GaN with other class D amps?
mcintech
128 posts
 
Hi,
While I love the small footprint, cool running, low current draw of Class D, there is one compelling reason I will not own one: as an audio repairman for almost 40 years (McIntosh Labs, Nagra, dCS, Musical Fidelity), I cannot even begin to repair a Class D amp.
Class A or AB  for me for the foreseeable future.
Cheers!Steve GeorgeNashville
georgehifi's avatar
georgehifi
10,312 posts
 
So, @georgehifi you have compared GaN with other class D amps?

Once again in case you missed it, or just inconspicuously trying to shill your own wares
  • Don’t need to, they are all variations on a technology that has an achilles heel that can’t be fixed.
  • Even Mark levinson tried to get around the problem with these massive monoblocks with very robust "higher order" output filters to get rid of the switching noise as to not effect the phase shift into the audio band, but it flopped also. https://ibb.co/YdVr6Wr
  • The only way is much higher switching frequency with low order filters that are also set much higher, aka Technics SE-R1 because of the GaN technology.

Cheers George
erik_squires OP
16,137 posts
 
Don’t need to, they are all variations on a technology that has an achilles heel that can’t be fixed.


But only George can hear it.

georgehifi's avatar
georgehifi
10,312 posts
 
But only George can hear it.

Not just me sunshine, everyone else that hears something wrong in the upper mids/highs with Class-D, you just don’t hear it, and choose to ignore that very big fact.
https://live.staticflickr.com/3666/33726831296_436f60f683_b.jpg

You say you can’t hear it that’s fine then live with it, but stop starting new Class-D threads to look for confirmation/cred from everyone about how good it is compared to the best linear amps.
When that old Class-D technology moves forward instead of sideways with the new GaN technology and make use of the 3 x higher switching speeds available, then it will compete with the best linear amps.

I’ve said it before, when Class-D can finally drive a pair of speakers like my big ML’s, Wilson Alexia, Alexandria or Watt/Puppies to their very best like linear amps can, then it will be time to sell my inefficient boat anchors, to purchase them.
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