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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
melvinjames
416 posts
 
Great thread Erik.

I've wondered about said deficiencies with class D also and wondered if it's because this class doesn't sound exactly like typical SS nor typical tube amps. Just my own limited experience but I don't hear these horrible deficiencies either. 

mijostyn's avatar
mijostyn
8,541 posts
 
I joined the Audio Circle and asked a few questions. I like the philosophy of the company very much. Low overhead, straight forward well executed chassis. The 1500 watt, quadruple rail version of the Megaschino is $17,000/pr. Not cheap!  I still can not find any info on how he is sampling and why. I think he holds that information close. He has a thread on planar speakers which seem to be an interest of his. I described my speakers and related that I would like very much to hear his amps. Not many amps drive my speakers gracefully. We shall see how he responds.  
erik_squires OP
16,021 posts
 
audiofun:
I used the self-powered version of the ICEPower modules, and I simply have not experienced the differences you did.

I did keep the amps far away from other gear though, and used ferrites on the power lines.

Best,

E
bigkidz
3,376 posts
 

OK I have a question. I have not listened to a Class D amp in recent years.  Way back I listened to the NuForce, Gilmore Raven and Channel Island Class D amps.  The CI was nice sounding and the Gilmore was the clear favorite.  The Nuforce did not impress.  A good friend on mine has the NuForce and upgraded the internal power supplies.  He claims they are much better and loves them in his system.  He visited me a few months back and plugged them in my system.  I am using an old Counterpoint SA-100 modified with better caps, resistors, added filter choke, etc.  The Counterpoint in my system was way better than the NuForce and I was pretty disappointed.  We did not really take the time necessary to try to see what was up.  Since then I have recently modified a few Counterpoint amps with bi-polar output transistors, class A output, all point-to-point wiring and those amps make my modified Counterpoint sound pretty bad, slow, no dimension, less details and dynamics, etc.  I actually knew that those amps would be that much better.


So my question is, if I was to try a current class D amp for a reasonable price, what would you recommend that I try out?  I would love to get an amp that weighs 8 pounds and sounds good.  I will have the opportunity to hear the Merrill amps next month to see how those sound.


BTW, I can build them if there are kits that sound very good.  I just have not had the time to research them myself at this time.


Thank you and Happy Listening.


My system:  Audiomeca and Metronome transports, my own components Vu Jade Audio 6SN7 preamp, Direct heated Triode DAC, Tube phono stage, and my own design Counterpoint power amp SA-100 and SA-220 which are really no longer Counterpoint designs, just using the chassis and transformers.    Speakers are Vandersteen Model 5As.  I think you can see my gear on this site under by member ID. 

Thanks in advance.


erik_squires OP
16,021 posts
 
Let me clarify myself, a little.

While I like Class D, and in some cases a lot more than certain Class A amps, I do think the ability for them to emit noise back into the power line or radiate it to nearby devices is not zero. So I advocate the uses of shielded power cables and using multiple filter banks to isolate them from other gear.


A detailed coverage of my thoughts on the matter are here:


https://inatinear.blogspot.com/2019/04/power-management-for-frugal-audiophiles.html


Best,
E
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