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
teo:

I understand your hypothesis and it is well articulated. The only issue I have is that I do not agree it is tightly intertwined with Class D operation. My AMR Phono stage is the best I’ve heard and it sounds great straight from standby mode but when that thing has been powered up for over 48 hours it is insane. Note that I said nothing about listening to it over this period of time, so it is not a brain-ear conditioning scenario. I’ve owned it long enough to know that is likes to be powered up for a while. It is why I power it up Thursday mornings as I head out the door and leave it powered until Sunday night. My Luxman EQ 500 could not care less ( if it could care :) about warm up, sounds the same from first hour to the last.

My Acoustic Reality Thaumaturges sound fantastic from power-up. They proved to me that class D can sound as good and in this case smoke many convential designs.

I have always believed garbage in garbage out. The power supply is the (in my opinion) most important thing. It is ultimately the power supply that is being modulated to create a facsimile of the original event.

I have three OTL’s, a S.E.T. (Reimyo PAT 777), a switching amp (mentioned above) and multiple push pull SS amps. I love them all and they all make music. Personally, nothing makes music like a well executed OTL but that’s for another thread :)
FYI, the retail price of the 507ux and ux ii in the US were identical until the latter was introduced.

The only difference in the two is a refinement in the feedback loop.
Luxman makes a lot of different models, so it is easy to confuse one for another, especially going by pics alone. :)

Best,
E
Let me first say I think Erik's post is great and I totally agree.

I have a Channel Island D200 fed by a Rogue Audio RP1 tube preamp into Harbeth Super HL5plus speakers. In moving to this system from a class A amplifier a couple of years ago I listened to a wide variety of electronics and speakers (to the point I’m sure vendors went "not you again" when I walked in. I was extremely impressed with the Benchmark, but it was out of price range. In one store I was able to compare what is now my system with a pricier but very good sounding all tube system and neither my wife nor I could here a major difference. I went with the class D in part because I decided I wanted to move away from hernia level components, although the price per pound of class D systems is much higher than class A solid state, let alone tubes.

One thing I find missing in this and almost every other discussion is the type of music being listened to. At audio shows I would bring some CD’s and a USB drive to try to listen to music I was familiar with. I listen primarily to classical music and two of the most revealing CDs were a recording of Mahler’s Fourth Symphony and Ravel’s Piano Concerto in G, pieces I am also familiar with from concerts. I found that systems that sounded good with the vendor’s selected music were frequently totally inadequate with mine. At a show, the best sound I heard with my music was the Benchmark with a speakers whose manufacturer I don’t recall.


My main point about Class D power warm up really is just to avoid making buying decisions based on a cold demo as you may get an unfair experience.

I'm not suggesting you listen to the D's for two days. That's not part of my recommendation.

Best,
E
erik, your main point makes perfect sense, and should regardless of new kit.

I would not make a buying decision on a unbroken in product of any kind (what audiophile would?). While I currently enjoy my AA DPA-1, I also bought a pair of PS Audio M700s that were likely sold for the very reason you state.

When I quizzed the seller, he said they had < 100 hours. BUT, several reviews indicated that they needed closer to 200 hours and then were pretty darn good, especially at $3K MSRP, let alone what I paid for them.

Alas, many claas D amps haven't gotten the interest from review magazines.  Still I didn't evaluate either of amps until > 100 hours break in, then another 100 using various mixing break in discs through the entire system. In both cases after 200+ hours, they got even better