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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
georgehifi's avatar
georgehifi
10,312 posts
 
This one too  devilboy

https://www.theabsolutesound.com/articles/technics-launches-hot-new-products/

From the Absolute Sounds review.
" The amplifier section delivers 100Wpc into 4 ohms (50Wpc into 8 ohms), and features a GaN-FET driver to perform high-speed switching with minimal loss for greater transparency"    
 
ricevs
1,543 posts
 

The Gramophone review said the Technics was not the most detailed thing around and the Hometheater review guy is now raving about a Levinson Integrated class A/B amp.  I guess Technics GaN amps have come and gone........and who the heck is going to buy the big Technics GaN amp?  anyone?  I have no doubt GaNs will be used in state of the art products some day.....but that day has not arrived.  Even the $36K Merrill does not have the depth or dynamics of the CH Precision.  There will be State of the Art GaN and other super class D amps in the future....the future looks bright.  However, today's $3K class D is really good.  But every single class D amp sounds different from every other one whether they are using Mosfets, GaNs, high switching frequency or low switching frequency.  There is no silver bullet.  Every single thing you do to an amp changes the sound....no matter what the class.  Everything has to be done to the nth degree or you don't get what is possible.  If you don't damp the heatsinks on class A/AB amps you add ringing sound....everything must be done right.  One spec or transistor type does not bring State of the Art sound.
tweak1
3,645 posts
 
Just an FYI, I was reading my Audio Alchemy manuals last night, Turns out it is not 175 wpc, but 125 @ 8ohms and 200 @ 4 ohms. No wonder the 350wpc PSA M700s sounded significantly beefier.

Now, if I could just get an update on delivery of my EVS 1200 from Ric...  it's been over a month since I paid for it (7/02)
erik_squires OP
16,021 posts
 
This is what I mean about George doing very little listening, and therefore making it hard for his arguments to be persuasive.

Most others on this thread, starting from myself, are commenting from actual listening experience.

Notice please in all my threads how often I’ve gone after listeners who post their personal experience. Never. I may not agree with them, but their experience is their own. When it comes to Class D in modern times, George rarely goes there.


Now, purely from theory, the Technics qualifies as an actual digital amp with DSP used to compensate for speaker impedance interactions. You can't separate the type of transistor, switching speed, and DSP to tell which is responsible for what.  I do think the DSP impedance compensation is very cool, but it means a second DAC in your stream.
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