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.
Not unless you have quite a few $K for the latest GaN ones at this time, still I would think is the Technics SE-R1. As they have fully utilised the higher switching speeds GaN technology has to offer.
From Audiophile Review.
In fact, that transistor technology is available today and is increasingly being used by manufacturers to create near perfect sound quality for Class D audio systems.
The greater switching speed of Efficient Power Conversion’s (EPC’s) eGaN® FETs allow amplifier designers to increase PWM switching frequencies, reduce dead-time, and drastically reduce feedback; in turn, producing a sound quality previously limited to large, complex, heavy Class A amplifier systems.
A high-definition eGaN FET-based system with higher PWM switching frequency, reduced feedback, and higher bandwidth produces the sound that has the warmth and sonic quality that audiophiles demand; while actually improving upon the power efficiency of traditional Class D.
@georgehifi, I can only take your opinions about GaN seriously if you have actually listened to some GaN amps compared to other class D amps. We know of somebody in the industry, who’s opinion we respect, who has compared top flight class D including GaN types and the GaN model was second from best. It also cost quite a bit more than the top design.
You have made your position on Class D perfectly clear. It would be nice if you would take a time out from the back and forth, especially since you haven't actually heard the newest offerings
Bottom line is, currently GaN offerings are quite expensive for the average audiophile.
I am confident I am not alone in saying GaN is well beyond my budget, as are even 'reasonably' priced Van Alstine amps.
Considering that I am quite pleased with my Audio Alchemy DPA-1 (175 wpc) but appreciated the much needed SPLs in my 19 x 34 room that the 350w PS Audio M700s did, I am excited to hear Ric Shultz's EVS 1200, dual mono @ 600 wpc, which is affordable at $2200 including shipping AND 30 day money back guarantee
I suggest you get one before continuing your ad nauseum mantra
tweak1, The latest TONE Audio review of Van Alstine SET 400 suggests it is somewhat tubey and forgiving. Since the SET 600 is merely a bridged version of the 400, the sound quality should be similar, although more powerful. The AVA site also describes the SQ of these amps as forgiving. There are plenty of amps with forgiving SQ, so even at $2K for the 400, this is nothing special. I seek accuracy, so I am with Ric Schultz who believes that for comparable money, accuracy can be achieved.
I am confident I am not alone in saying GaN is well beyond my budget,
@tweak1 FWIW these days GaN devices do not cost any more than regular MOSFET switching power transistors and in some cases are cheaper. Their implementation in a class D circuit does not cost any more either. Armed with this knowledge it might be interesting to ask a manufacturer of a GaN-based class D amp why their amp is so much more expensive.
viber6, I think Ric Schultz said he could make theVan Alstines' sound much better. That's what I was referring to, though I failed to include it in my post
Ralph, not meant to be insulting, but couldn't you sell your products for a lot less? Nothing there that's cutting edge, though I do understand that highest quality parts cost significantly more
And wouldn't the GaN input buffers need to be a lot more exotic= $$$?
Armed with this knowledge it might be interesting to ask a manufacturer of a GaN-based class D amp why their amp is so much more expensive.
You’d have you been asleep, that goes with any new ground breaking technology eg:TV’s The first models in audio by the boutique manufacturers are always sky high priced because they make their own boards, then once that new technology has proven itself to be the future, those pesky people in Asia like get hold of it and design and manufacture complete boards in the millions for a $100 dollars, that’s when the smaller manufacturers get them and charge too much because they put them in glitzy chassis and charge a fortune and rest on their past names.
soundsrealaudio....."Hum class D....should I sell my 300B???"
YEs TI appears to have GaN based Class D modules now and can’t imagine those cost much more than their others. Anyone know of amps that use these?
FWIW I have a ~40-50 w/ch Fosi Class D bluetooth integrated amp that uses a TI Class D module. It’s slightly larger than a pack of cigarettes and <$100 on Amazon. It is not GaN as best I can tell but the sound is quite impressive especially for that price. It replaced a classic NAD 3020 receiver. Sound is night and day different from the old NAD. Much more detailed and holographic, less warm, and less fatiguing to boot.
Ralph, not meant to be insulting, but couldn't you sell your products
for a lot less? Nothing there that's cutting edge, though I do
understand that highest quality parts cost significantly more
And wouldn't the GaN input buffers need to be a lot more exotic= $$$?
All of our products are built by hand, and to that end set a pretty high bar in terms of construction quality. Despite that we are expecting our first class D entry to be less expensive than most of our amps are right now.
mapman Yes TI appears to have GaN based Class D modules now and can’t imagine those cost much more than their others. Anyone know of amps that use these?
Thanks for that info. Didn’t think it would be long before big companies like TI (Texas Instruments) got into GaN for audio use, others like Motorola ect will follow
Here is a snippet from TI’s propaganda on the GaN technology.
"GaN FETs provide superior switching characteristics, which enable even higher efficiency, better thermal sinking reduced size and weight, as well as reduced distortion for Class-D audio solutions.
GaN’s inherent characteristics provide a more ideal model of a small-signal PWM, driving the output filter. Along with this, the absence of a body diode eliminates reverse-recovery charge, which enables increased output linearity. Both characteristics allow GaN to minimize THD and ultimately create higher-quality sound."
Not sure if you are intimating that it is the ICE tech that is an issue (to you) or if the SMPS is not a problem to you.
I have not, and will not, use the term SMPS to refer to a power amplifier in general, since the last two initials stand for "Power Supply." To use SMPS to refer to a switching audio amplifier in total is incorrect. It negates several components entirely, and fails to acknowledge the improvements that have been made to make it wide band.
ICEpower refers to a particular brand of Class D which is owned by B&O. ICEpower 250 ASP is a specific model of amp which includes a power supply in it, and it is what I have the most amount of experience with.
To repeat my original message: The tropes about the terrible sound quality of Class D amplifiers are not supported by any of the many reasonably good Class D amplifiers out there. Nor is there any evidence that you can hear the switching noise anymore. Not for decades.
If we want to talk about the positives, and negatives, we have to stick to experience and specific models. All amplifiers have a negative. All have something they could do better or differently. Seeing 1 measurement and going "look look, Class D is terrible" is not scientific. To close the loop, you have to connect it with listening. And that’s where a lot of anti-Class D bias looses all of its wind.
Again, referring back to my original post. I like this specific model of Class D better than some linear amplifiers, but not better than the Luxman I'm listening to now.
With this specific example, and I don't think it was by any means the best available today, I never heard anything that said "Class D." So I imagine that not only are there a lot of other Class D amps that don't sound bad, but that they've made significant strides.
Yes expensive also but they are the new GaN Class-D technology, stuffed inside a stupid tube housing, to keep the tube guys happy.
This is hilarious. You must live in an all grey world
While it's true that the tubes do nothing, they are pure marketing genius. The tubes have probably done more to draw attention to GaN tech then anything on the market
And as I understand it, the parts in those tubes make up the main portion of the GaN tech, and as such, when the tech improves, these can be simply pulled out and replaced, instead of having a door stop or spending lots of money returning to manufacturer for upgrades
A few years ago I did a local sale on a Conrad Johnson tube preamp which was connected to a Class D amp. When the buyer came over for a listen his first question was, what kind of amp is that? He then went on to point out how impressive the two sounded together and yes he did purchased the preamp.
Interesting this thread seems to have no end in sight. i have a Peachtree Nova 150. I enjoy it very much. I think Class D amps are only going to get better. To each his own, agree to disagree.
A few years ago I did a local sale on a Conrad Johnson tube preamp which
was connected to a Class D amp. When the buyer came over for a listen
his first question was, what kind of amp is that? He then went on to
point out how impressive the two sounded together and yes he did
purchased the preamp.
This is one of my classic combinations!! CJ pre with solid state amp. I haven't tried Class D with ESLs, but in the past I loved that combo.
While it’s true that the tubes do nothing, they are pure marketing genius.
People that get sucked in buy this "pure marketing genius" are what I call a "glitz queen" and this is the reason he has a $15k odd price tag on them. When what’s inside amounts to a few hundred dollars. How could he then charge $15k odd for a small grey box.
It’s not marketing genius, this is feeding on the gullible.
Even he said in an interview, it’s bulls**t, and just there to amuse the tube freaks.
Supertramp Eric their song was written for you. You are dreaming, at best Class-D has a 40-50% share over linear, and that’s mainly for low to mid fi and subs, in the hi end it favors linear much more
You have to put down the axe and stop grinding it!!!
I was participating in a class D thread maybe 6 months ago or more and you were dumping on class D then too. If anyone does a class D search going back 10 years, you were there dumping on class D then.
Remember what I said to you last time??? I think its pathetic that you cant let anyone enjoy class D. You did the same thing in this thread. I love my Red Dragon Pascal S500s. You said they are made in China by this sangia or whatever it is last time too. I don't care where Pascal manufactures their amps.
Like someone else said, you can keep crusading your anti class D agenda, but no one cares what you think. You aren't converting anyone, you aren't making anyone a class D hater like yourself.
I am not saying my RD S500s are the best, but they are pretty dam good especially for the money. There was a review of the S500s vs some 30K Luxman monos. The reviewer said his Luxman were better, but not by much. When you consider 30k vs 4k (2K on sale) I don't feel short changed at all. There are some mighty fine class D amps out there such as the D Sonic, Nord Acoustic, Red Dragon, Apollon, and a whole bunch more.
Nobody is saying your class A/AB aren't any good and by all means enjoy your gear George. Let others enjoy class D. I would encourage anyone to try class D. You might love it, you might hate it, you might prefer your class A/AB. My point is don't let a anti class D crusader stop you from trying anything.
I sold a pair of speakers a couple years ago and I was using a ClassD Audio SDS470 to power them. This diehard tube amp guy came to buy the speakers. He asked what amp are you using? I said its a class D and hes looking at me with this priceless bewildered look on his face. I think he even said it twice...this is class D...this is class D. At any rate he thought it sounded pretty good.
One thing I do like about my class D over my former class AB is they do run a lot cooler and are waaaay more fuel eficient. I leave my S500s powered up all the time because they only use a few watts idling.
I was just going by memory on the review, but it was a 6 Moons review. The Luxman amps were 2 x M800A @ $16,000 each vs 2 x Red Dragon S500 @ $2000 each....or the RD super sale the S500s were only $1000 each. So as I said 32k vs 2K...forgetaboutit lol
Hey maybe if I won the lottery and cost wasn't an issue. I might go for a full blown Gryphon pre/amp system, but until then I will have to force (lol) myself to enjoy my lowly made in China or wherever S500s. They are actually a good match for my made in China tube DAC.
George: I clearly meant you are outnumbered here in the forums, with most people responding at least not trying to hijack a thread with a strawman army. You are also vastly out gunned, with responders bringing in personal specific listening experiences which are far more valuable than your uncorrelated theories of why current Class D must sound bad.
Also, in terms of music listeners, I'd bet right now the ratio is 70% listening via some class D, probably voice controlled appliance.
You are dreaming, at best Class-D has a 40-50% share over linear, and that’s mainly for low to mid fi and subs, in the hi end it favors linear tube and solid state much more.
And you and your mate tweak have your heads buried in the sand, if you can’t see the advantages of GaN technology used in Class-D over past/present technology. Guarantee you’ll be one of the first in line to get a GaN one when they meet your price expectation. Why not embrace it, you can’t stop it from coming that’s for sure.
Aren’t GaN amps pretty expensive? At least the one manufacturer I heard about is.
I have 100 hours on my PS Audio S300 and it sounds absolutely lovely driving my Selah Tempestas. My last system was an Almarro integrated using the 6C33C driving a pair of Rethms. Two very different approaches for amplification and speakers and I’m enjoying it just as much.
I’ll start a new virtual systems in the next week or two.
Oh and George, one more thing. I don't want to hear anything about Gan amps if they cost $40,000. I'm sure they're fantastic and probably a breakthrough in the technology, but frankly that's out of the ballpark for 99% of us. As with everything else, one day it will trickle down and be available in amplifiers under $2,000 but don't tell me I need to spend an exorbitant amount of money for class D to sound good.
" 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"
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.
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)
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.
I won't be responsible for George's lack of self control. If I can't say "I like Class D" without him abandoning his family, friends and life to respond with hundreds of pages of random facts about Class D it is not my fault.
This is what I mean about George doing very little listening, and therefore making it hard for his arguments to be persuasive.
You and your mate tweak give/present nothing technical in your posts to why using old present Class-D technology is as good as the new GaN technology, all you guys can do is attack on a personal level.
If I can’t say "I like Class D"
An I’m not saying you don’t like your Class-D, as your many threads you have started on it state. Just look at what the new GaN technology will bring to it, and fix it’s achilles heel it has in it at present, that you obviously can’t hear but others do, "dead time" and "switching noise frequency"
ricevs I have no doubt GaNs will be used in state of the art products some day There will be State of the Art GaN and other super class D amps in the future....the future looks bright.
+1. I finally agree with something you’ve said, could it be you've seen the
There are people who say they hate class D. I'll bet that if you sat them down and played some music and told them that the amp they're listening to was a $10,000 class A or class A/B amp, they would say it's fantastic. I believe that a lot of the negative criticism that comes with class D amps is from people who already have a preconceived opinion of class D which convinces their brain that it's not good before they even give it a chance.
I believe that a lot of the negative criticism that comes with class D amps is from people who already have a preconceived opinion of class D which convinces their brain that it’s not good before they even give it a chance.
Tell that to these brain trust guys, it’s the same technology now as it was then, may have moved sideways a little, but still basically the same.
Cyrill Hammer of (Souloution Audio knows very well about the Class-D’s achilles heel, and says so, which GaN can fix, and why you few doubters should embrace it, instead of putting **** on it
The only one to give it any credence is Jeff Rowland, I wonder why? does his company make Class-D?? yes it does
Bob Carver "I built many of them right here in my own laboratory with the thought they could and would fulfill that final promise.... I was never able to build a Class D amplifier that sounded as good as a linear one."
John Curl (Parasound, CTC, Vendetta Research, Constellation) "Some version of hybrid Class A/D looks like the future in optimum audio design."
Cyrill Hammer (Souloution) "if you want to have your product performing at the cutting edge it is not possible with today’s known switching technologies. In order to come close to the performance of the best linear design we would need high-current semiconductors that provide switching frequencies of several MHz or even GHz."
Lew Johnson (Conrad Johnson) "I tend to think that Class D circuit design is an approach best relegated to producing low-cost, physically manageable multichannel amplifiers—where one might accept some compromise in sound quality for the sake of squeezing five, six, or seven 100 watt channels into one moderate-sized package for a budget home-theater installation."
Vladimir Shushurin (Lamm) "No, it is not. And I would like to respond to the second part of this question with an allegory. Any field of human activity defines a number of requirements which, when properly implemented, guarantee a positive outcome. For example, the basic requirement in the army and sports is an able-bodied individual. So, it would be quite natural to concentrate on searching for such an individual (especially as we know where to find him). However, out of the blue we decide to choose a feeble-bodied person who, on top of that, is encumbered by various diseases. Having made this decision (which is a priori improper) we start justifying it to ourselves and others by citing the great state of our medicine, which is capable of curing many ailments."
Fumio Ohashi (BAlabo) "No. Class D can’t really be considered for super-high-end performance in its present stage of development, although it can be fine for mid-market products."
Nelson Pass (Threshold, Passlabs) "Does a $10 bottle of wine compete with a $100 bottle? Of course it does, and it often wins based on price. Right at the moment Class D designers seem to be still focusing on the objectively measured performance of their amplifiers. I expect that at some point the economics of the marketplace will encourage them to pay more attention to the subjective qualities, and then they will probably play a greater role in the high end."
Jürgen Reiss (MBL) "I have worked a lot lately with Class D. Ninety-nine percent of Class D circuits are not competitive with linear circuits. Most Class D sounds sterile. It’s tricky to figure out what to do to compensate for that."
Jeff Rowland "I consider Class D to be highly competitive in the present, and to offer an evolutionary pathway of audio design that may produce even more astonishing results in the future."
Thorsten Loesch "I have yet to hear a pure class D Amp I’d rate above "below average for solid state" (which is not very high performance). In a little update of my classic "Valve Analogue Stages for DAC’s #" I wrote: "Perhaps more crucially, so called Class D Amplifiers, which have in recent times sprouted up like mushrooms after a warm rain, continue to use the straight two or three level modulation scheme described above. And thus they still require the use of heavy handed noise shaping to attain anything like acceptable 16 Bit Audio performance. The clock frequencies for these amplifiers are usually at 300 KHz to 1MHz in the best cases. That is 3,000 to 10,000 times lower than what is required to attain 16 Bit / 44.1 KHz performance without noise shaping and other forms of signal manipulation! And again, one is baffled and perplexed by the rave reviews many Class D amplifiers receive, as baffled as one was about the late 90’s reviews of timeslicing dac’s. The best of breed I have auditioned were certainly not bad; however in direct comparison to the best available valve and solid state amplifiers they do not produce a very good sound. Well, at least they offer novelty and the reviewers something to write about other than another (however good sounding) 8 Watt valve amp. Incidentally, the best sounding Class D amps tend to be really low power single chip devices (putting out little more than the 8 watt valve amps), presumably because they are faster AND because they always work near what one might call “full scaleâ€, if they would be dac’s. On second thought, they of COURSE are DA Converters and where a Class D amplifier accepts analogue input directly it is an A2D converter followed by a power D2A converter! What an insight!?" Mark Levinsons interleaving of multiple Class D Amplifiers is potentially a step in the right direction, but does not go far enough. Personally I think that the best option would be something that combines a Class D Amplifier for the heavy lifting with something Class A for fine detail. Probably implemented in the style I did for AMR’s AM-77 "Jikoda$" Style. In this case both of the circuits involved can operate fully open loop. In many ways the problems in Class D Amplifiers are analogous (but not identical to) those in Class B Amplifiers (but without an option to implement Class AB or Class A) so similar solutions apply. All Class D amplifiers are essentially delta-sigma DAC’s. If the input is not digital PWM signals (aka "DSD") but analogue audio then it is also a Delta Sigma Analogue to digital converter... Now DSD (aka SACD) which to my ears fails to come close, never mind equal true PCM CD Replay in most aspects of sound quality, operates at 2.8MHz switching, or around 10 times as fast as common Class D Amplifiers... Why anyone would want to listen through an A2D followed by an D2A Converter that are around 10 times worse than single speed DSD is beyond me. But with enough hype and snazzy naming it cannot help but sell high and wide.
A tidbit for the anti D crowd, recently a friend who has been out of town came by for a visit. We used to jam quite a bit and he did not know my Krell Kav 250 died and is temporarily replaced by an Emotiva Gen3. While jamming he exclaimed that my sound was the best he's heard yet. Go figure. He still don't know it's class D. All his amps, yes multiples, are class AB and sound fantastic. Maybe he's getting hearing problems, but if so I must be too. The plan, when the Krell died, was to get an inexpensive amp with lots of power, then save for a parasound halo but now I'm more inclined to try a better class D such as Dsonic True story
A tidbit for the anti D crowd, recently a friend who has been out of town came by for a visit. We used to jam quite a bit and he did not know my Krell Kav 250 died and is temporarily replaced by an Emotiva Gen3. While jamming he exclaimed that my sound was the best he’s heard yet. Go figure. He still don’t know it’s class D. All his amps, yes multiples, are class AB and sound fantastic.
Sorry to burst your bubble gillatgh, I maybe wrong, but for memory I think you’ll find all the Gen 3 Emotiva’s amp are linear Class-A/B driven from Class-H power supplies. They make a cheap $300 budget Class-D called the PA1, PA standing most likely for "Public Address" amp.
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