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
George,
What amps have you removed the output filters from so you can test your "idea"?  What amps have you raised the switching frequency on so you can again....test your "idea"?  You have interesting ideas.  That is all they are.  You have no proof.  More and more people everyday are listening to 500K switching amps using mosfets and they do not hear the "terrible mids and highs" you keep talking about.

On the other hand, I agree with you about switching at higher frequencies being a "possible" positive (apparently hard to do without drawbacks....Merrill even says so).  You could make the coil smaller and it would have less effect.  As far as dead time there are various ways of dealing with it.  Everything will be known about all this within 10 years.  In the mean time we have great sounding relatively modest costing mosfet based amps that are replacing class A and A/B amps all over the world.  Not that any class D amp (including the new Merrill GaN amps) is state of the art.  I am sure the $100,000 plus Class A amps are still the best there is (Audionet Heisenberg, DAgostino Relentless, etc.).

I really hope that GaN transistors can help class D get even better.  However, there is no proof yet.  Even the $36,000 Merrill GaN amps don't do depth or dynamics or classical music as well as the CH Precision stuff (according to one guy who had them both in his house).  Most of the class D amps out there are inexpensive, use off the shelf modules (including mine), are not being produced by serious tweakers, etc. and therefore are compromised.  I do 17 mods to the modules and hook them up in state of the art ways and sell wholesale direct.  This is why my amp is so good for the money.  It is not state of the art.....no way.  State of the art means the best available period.....Heck, that bar keeps changing every year....even at the $100K price range.  Class D is very good right now and will keep getting better and better at cheaper and cheaper prices.  If GaNs can help this trend then all is a WIN!  I have high hope for GaNs...let us see what happens.  Right now there are no (zip, zero, nada) tweaked out affordable GaN amps available (the inexpensive Technics is not a tweak product!!!).  This is going to take some time.  What is for sure (and I keep saying this over and over....so here goes again)......is that every amp with GaNs (when and if they get released) will sound different from every other amp with GaNs or whatever.  Every single thing you do changes the sound.  Unless you invest tons of time tweaking something you will never get what is possible.  I have been tweaking the IceEdge modules for a year now and am just now starting to ship.  Perfecting and tweaking takes time.  You will have GaN amps that do not sound as good as mosfet amps.....that I am sure of.  There is no silver bullet.  Everything has to be done right.  I hope that GaNs done right are another level better....I always want everything/everyone to improve.  I want everyone to feel happier and happier with each day.  May it be so.
Ric hits the George issue on the head, eloquently. Not that his eloquence or reasoning will dissuade George from using cherry picked measurements to assert issues with Class D which are almost solved.


ricevs,
What amp have you heard side by side with your EVS 1200 that makes it "better" or SOTA, whatever that means?  I am not impressed by high  retail prices on hyped big brand names.  I heard an Audionet that was warmer and rolled off compared to the Mola Mola Kaluga.  D'agnostino amps are euphonic and rolled off, according to a few posters on various threads and a dealer I know.  The Audionet Heisenberg and D'ag Relentless may have high power, but there is no indication to make me think that for accuracy they are SOTA.

The latest Heisenberg is suppose to be way better than the old Max......same with the Relentless.  The new DAgostino has .003 percent distortion at full power, .03 ohm output impedance, 100K  bandwidth...all with no feedback!!!.....this is staggeringly better than any other Dag amp.  The old Dags measured just so so but some really liked their warm sound.  I have not heard either.....just what I gleam from reading reports from those that have heard.  My point is that you cannot expect SOTA at $2200.  I am sure there are better amps than mine.  How much more you would have to spend?  We shall see. 

Here is an interesting factoid.  The new Relentless amps have binding posts made out of massive brass.......yes, custom massive thangs made up of super lossy material.  Why would you make a "SOTA" contender amp and then put horrible brass connectors on the output.  They could of made them from copper, OFC copper, cryoed OFC copper, PCOCC copper, silver or ?  Remember, this is a quarter million dollars and they are mounting veiled hardware on the output.  I sent them an email about this but I am sure they will pay me no mind.  If they used the latest low mass Furutech or WBT copper or silver connectors they would have mucho better sound.  My binding post bypass system is even better.....but would not pass their "must look sexy" thang.  By the way, they are using $5 Neutrik xlr connectors on the input.  I use the much more expensive and better sounding  Furutech ones.....also better are the Cardas ones.  So, just imagine how much better the Relentless would sound with better input and output connectors.  Do these people really listen? 

Of course, when you get your Relentless amps installed you can bypass the hardware and hardwire.......he he.  However, this is how I listen....I hardwire two feet of custom balanced cable from my modded Oppo 205 to the custom input stage on the modded IceEdge module.  I solder my speaker wires directly to the module and directly to the xover in my speaker.  The first rule of tweaking is: remove everything not needed.

George,
What amps have you removed the output filters from so you can test your "idea"?
Your kidding, your tweeters wouldn't last a nano second, if you didn't know??.

What we have here creeping up are manufacturers using the threads to promote their new Class-D products, it’s not on guys, there was one removed/banned totally from Audiogon not so long ago, take heed.