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.
I’ll say something positive about class D, and wait for George to say something negative about class D", thread.
Seeing you mentioned me,that's where your wrong and deluded, and non technical. . I only have about the old Class-D technology, not the new GaN Class-D, which I have nothing but praise for "if" used to it's fullest.
Simply put for you, because it, (GaN) removes the old technologies achilles heels x 2 (dead time and switching noise), x1 (dead time) if not used to it's fullest, as some have done.
While I appreciate all of the class D supporters, as I also am a fan, this thread has turned into an, "I’ll say something positive about class D and wait for George to say something negative about class D", thread.
Having owned multiple class D amplifiers from multiple companies and multiple single-ended triode amps and multiple push-pull tube amplifiers and multiple class A amplifiers and multiple class A/B amplifiers over 23 years......... I will say that, just like women, I’ve loved and hated something about all of them.
In the end, I think audio and women share a striking resemblance. We all search for the perfect audio component or woman. Neither of them exist. It’s just a matter of how well we can tolerate the things that make them annoying.
I can tolerate my current class D amplifier to the point where it may have short cummings but in the end, it pleases me and makes me a happier audiophile.
This post may not convince any class D haters but who cares? In the end, if what you’re listening to makes you happy, then just listen and be happy.
Phil has some balanced cables but not ones he likes. He is now a super fan of the Teo liquid cables. But he only has them unbalanced It is very hard for him to change cables (crammed space..using mirror, etc.) so he is waiting for his custom balanced Teo cables to arrive before changing cables again.
I have a couple different XLR cables I could send, but neither comes close to my WireWorld XLRs, and that could be the issue many are having; that being their ICs and speaker cables simply are not a good match for such revealing amps
Phil is waiting on balanced cables to really hear the EVS1200 amps (listening with rca and adapters now). Will be a week or so before he chimes in. The amp sounds so much better balanced I have decided that it is a balanced amp only and will be shipped with xlr inputs only from now on.
klh007, Can we hear about sound quality of the Mivera vs EVS 1200 amps, rather than concentrating on dynamics only? For me, purity and clarity at moderate SPL is far more important than loud, lower quality sound. If an amp has lesser clarity at moderate levels, I don't want to hear the mediocrity at loud levels.
Yes, I've read Phil's comments on the various forums - nice guy!
And I agree with everything you've mentioned in your post.
The Watt/Puppies go down to 1.8ohms vs 2.4 - 2.8 ohm for the Thiels. So they are a bit harder to drive.
I'm not sure comparing the 1200as2 to a Bryston amp that would shut down is saying much.
At first I thought my system sounded pretty good with the 1200as2 amp, but I had someone else come and listen and he convinced me there was a lot missing. I went to his place and realized what a decent system should sound like.
Yes, the stock IceEdge modules are compressed sounding (dynamics, soundstage, etc.). Not the modded mono boards I sell. I do 17 proprietary mods to the boards (in addition to the super wire, Furutech IEC and XLR jacks, binding post bypass system, damped chassis, mounting the boards on multilayer copper/aluminum plating, etc.) You will read here comparisons with the stock module and other amps soon.
The problem with dynamics has nothing to do with class D. It has to do with execution. By the way, dynamics are never what George has complained about.
My friend Phil in FL has a Mivera 1200AS and the first pair in the wild of the EVS modded 1200AS amps. He has been driving a difficult and low sensitive load of Thiels that shut down a big Bryston, he is surprised how effectively the Mivera drives the Thiels to loud levels and barely gets warm, I think he is pumping a lot of current into them. He likes the EVS modded ones even more.
Actually, Erik just said what I meant to before having a couple of pops last night. Class D is just another class. It may be better in some applications, the same, or worse.
My point was that there appears to be twice as many class D promoters talking about class D "haters" than there are class D "haters".
For the record: I've heard plenty of audiophile marketed, linear solid state amps which were pretty sensitive to speaker and cable impedance.
As my original thesis points out, we need to think about Class D amps like amps, with all their possible blemishes, instead of trying to assert an amp-class hierarchy which no longer fits current products.
I'm basing my comments on actually owning 2 of the Icepower 1200as2 amps. The only conclusion I've said was that you'd be selling your amp within a year. I hope I'm wrong, I hope you enjoy the amp. Just know, the resale on your amp won't be very high.
I believe this is what Georgehifi is also referring to in his comments.
Especially in the upper mids/highs
golfnuttz, 100 times? you tend to over exaggerate and are a bit misinformed;
That would be you, not golfnuttz as many others hear it also, and it just "happens to be" where passed/present day Class-D technology has it’s achilles heels, in dead time and switching frequency issues, and GaN Class-D Technology if used for all it’s worth fixes both these issues, as presented to you from the inventors, (EPC), the manufacturers TI (Texas Instruments) and Technics with the SE-R1 and to a degree the SU-G30 (dead time not higher switching frequency).
Seriously tweak? Do you really think 2 1200as1 are any different than 2 1200as2's? As for difficult loads, you'll only know if you have inefficient speakers. In my system, it was a flat wall of sound with no dynamics at all. How many times can a person mention the same thing over and over again (EVS amp) before you think they are trolling?
Can’t say for sure but what I was able to find about the Mivera amps referenced the Icepower site for specs, so likely its just that Icepower module in a nice box, which perhaps is just not up to the task of driving demanding "audiophile" speakers to their max all alone.
Most applications are surely not as demanding.
Ref1000m amps listed for $6k a pair originally. I bought mine used for half that price. Not cheap, but that was my best shot at driving my demanding home speakers to their max which worked out well. The input section on ref1000m also allows for good pairing with my higher output tube pre-amp. The input impedance of the stock Icepower module used was only 10Kohm, not good for use with tube pre-amp but fine if SS pre.
golfnuttz, 100 times? you tend to over exaggerate and are a bit misinformed; IcePowers' ability to drive difficult loads, oh, and FYI, the EVS consists of 2 1200AS1s’ which are mono modules
I’m not disagreeing with you. I’m only talking about my own personal experience, which matched what Georgehifi was saying. I’m sure it’s not just limited to the Icepower modules, but that doesn’t mean there aren’t great class D amps (even for inefficient speakers).
I’m not sure the Icepower 1200as2 was even designed/intended for stereo/mono amps based on these comments: "Intended for PA speakers, line arrays and professional single or dual sub-woofers"
You must have mentioned the EVS amp 100 times in all your posts so far. For someone with 40+ years experience, you sure have a lot to say about something that you never heard. You accuse others of being trolls, and basically that's all I see that you are.
All amps work better with higher-impedance loudspeakers.
WHere they differ is how well they work into more difficult loads.
The ref1000ms do fine with most speakers. None I have tried dip down to 2ohm that I know of, but then again I would tend to avoid any speakers that do.
"Fortunately, music rarely includes enough high top-octave energy to reveal the amplifier’s unhappiness in this region."
I have no gripes about the top ends of any of my Class D amps playing the great variety of music and recordings that I listen to, but clearly at least on paper that is where ongoing improvements in the technology will probably best make it’s case. In that sense I agree with George.
I don't know much about the Bel Canto Ref 1000, but I did see comments on Stereophile that said this:
"This latest version of Bel Canto's e.One Ref1000M monoblock offers very high power from its diminutive chassis. It does work best with higher-impedance loudspeakers, however, and at lower frequencies. Fortunately, music rarely includes enough high top-octave energy to reveal the amplifier's unhappiness in this region.—John Atkinson"
I believe this is what Georgehifi is also referring to in his comments.
I have owned quite a few class Ds, including my current (npi) Audio Alchemy DPA-1 (125 wpc) which sounds terrific (see Mar/April 2016 TAS Review) and PS Audio M700s, which sounded excellent and provided a lot more spl in my big room
The only reason I still have the DPA 1 is that no one wanted it when I put it up for sale, but the M700s went qucik, as they should have.
The EVS comes with 30 day money back, so if my experience is similar to yours, it will be returned before I take full ownership
Yes, the 1200as2 is the Icepower module. By no means am I bashing class D. All I am saying is that this module does not do well with inefficient speakers (watt/puppy). I also have Pass Labs amp, and the comparisons are night and day (not even close). When I initially purchased the 1200as2, I wanted to use them for Home Theatre, but decided it wasn't the way to go. I had 2 of these amps and was going to get a third, but I made the decision to just keep my 5 channel Parasound amp.
IS 1200as2 the IcePower module? What amps specifically are you referring to that use it?
The overall design matters. For example a Bel Canto ref1000 (older ice module in a nice box) is not the same as a ref1000m which is same ice module + custom input section and power supply in similar nice box. Both are spec’ed at 500w/ch into 8 ohm. The ref1000m’s are the only amp I have ever owned capable of driving any speaker I throw at them to their max and never ever even comes close to breaking a sweat. The sound is smooth, non-fatiguing and totally effortless at any practical volume, another first experienced for me.
So any claim that Class D can’t do that is totally wrong. As is anyone who might claim any Class D can.
Even the TI Class D module in my $85 Fosi amp is capable of more if integrated and housed towards that end where the extra heat generated is able to dissipate.
The devil is always in the details, Class D or otherwise. Avoid drawing generalized conclusions from limited evidence much less on theory alone.
All I'm saying is what George is describing has been my exact experience. There is no way the 1200as2 is a high current amp putting out 600w (8ohms) or 1200w (4ohms). It might do well with efficient speakers, but it does not do well with inefficient speakers.
Your experience is your experience as mine is mine and others are theirs. I’m saying yours is possible despite mine for many possible reasons. Please don’t say others aren’t because of yours, especially when there are specs and measurements in many cases to support specific claims like high current delivery with specific models/designs.
High efficiency obviously is a factor that helps enable high current delivery capabilities, not hinder it.
As for George, with all due respect, his comments regarding Class D seem based largely on theory, not on practical experience. Maybe I missed something?
I believe georgehifi mentions something about inefficient speakers, and that's what I'm referring to when paired with low-end class D amps. The Icepower 1200as2 were supposed to be the next best thing, however, that wasn't my experience.
Just spoke with ric via phone, looks like mine will not be ready to ship until late next week. I told him he should let people know what his time frame is. I think he’s been preoccupied but now ready to stay focused
Hard for me to imagine zero improvement when direct soldering and using high end fuse, but then a lot of people seemingly cannot hear when polarity is out, so...
Golfnutz you are drawing conclusions based on way insubstantial evidence.
There are in fact many high current Icepower based Class D amps out there and have been for years.
I own two: the BEL Canto ref1000m and the C5i. Look em’ up. I’ve used these with great results with various power and current hungry monitors and full range floor standers including Dynaudio, KEF, and OHM.
I also own a third newer (Fosi) that is a minimal design built around a TI Class D amp chip that only cost $85 and still sounds great with a pair of limited range small monitors (refoamed vintage Boston A40s...very nice). I don’t expect anything at that price to be able to drive a very difficult load but I suspect this one is also at least very efficient and probably can at least as well as most anything else anywhere near the price and certainly anywhere near its size (about the size of a pack of cigarettes).
By my estimate, the Icepower 1200as2 is around the $300 price per module. For the money, it's pretty good. Not so good for inefficient speakers though. All connectors on the 1200as2 are JST, using tin. I've had every single connector connected directly to the board (power/input/output), also using a high quality fuse. There was ZERO difference between direct/indirect connections. This is not a high current amplifier. My SS amp is much more dynamic and louder at a much lower volume setting. I'm afraid I agree with what Georgehifi has been trying to tell everyone (at least for lower priced class D).
This conversation turns a lot of my Audiogon impressions on their head.
People who, I think, believe that great sound qualities can’t be
measured are at the same time suggesting that because of inherent
measurable design challenges of class D, that no class D amp can sound
good. It also seems that more measurement-oriented folks may be coming
out against class D because...I don’t know.
Let me be clear, I like measurements. But a measurement is not inherently audible or valuable. An oscilloscope does not work 40 hours a week, and go home to listen to music. There's a big difference between a measurement and pleasure or desirability.
If there is 100kHz noise on an output, I'm not convinced it is audiuble unless I can hear it. If you go from 0.01 to 0.00001 distortion I'm not willing to pay 1000x as much for the latter.
People who cherry pick a measurement to make broad claims about the inferiority of one technology over another are not objective. They are just biased.
@georgehifi there are different types of audio dealers, most are not very knowledgeable I find and haven’t heard or bothered to hear a wide range of equipment, they sell whatever they have. They don’t even know about things like the importance of seismic isolation for example or their approach to this may be totally wrong and inadequate. Then there are others that are more thorough, test out different brands and only represent a few that are value for money. They also have the knowledge about setting up equipment properly and know about important aspects like seismic isolation, cabling and mains quality. I like to think we fit into the second category.
Anyhow, back on topic. The performance of class D varies enormously, there is good and bad. Even a manufacturer using the same class D modules will sound different depending on the implementation used. So just because a brand uses a Hypex NC something module, for example, doesn’t mean they will all sound the same.
And, as I have said before, just because an amp employs GaN it doesn’t mean that it will automatically sound better than other class D amplifiers that cost a lot less.
jetter, Also, tweak1 likes his Audio Alchemy DPA1 stereo amp, which is class D. I agree that he may be eagerly anticipating the EVS 1200, but when he gets it his ears will tell the truth.
Whether you are interested in my reports is up to you
Do not confuse me with the facts
I have been an audiophile for 40+ years and even owned a retail company, and have read a ton of magazine reviews that left me perplexed as I had owned a fair amount of the kit in those reviews and did not have the same glowing experiences
As to actually hearing mine; it’s been over a month since plunking down my $2200, and still nothing from ric, which IMHO is not good business, so I am not a happy camper.
If it doesn’t significantly outperform my AA DPA-1 it will be returned for a refund
Other than George's post by manufacturers who would be expected to praise the virtues of their amps, the common post by those who support class D is that the rest of us are class D haters.
In fact, on A'gon, there are 10 class D posts calling us class D haters as there are posts by class D haters. IMHO, most of us just don't think about it that much.
Tweak, I was excited to hear your evaluation of your new amp as I was considering purchasing one, but now that you are already posting like a loyal supporter before even receiving your amp (or hearing one?), I will take your evaluation with a grain of salt.
Fortunately (for those of us who are in the market for a new class D), ric is not governed by the budget constraints of manufacturers who are not interested in going the extra mile, but will spend said monies on a prettier face plate.
Ill bet his speaker binding post bypass ALONE is revelatory
@georgehifi, I stand corrected, you are correct. For whatever reason I was under the impression that it was a class D amp. It is not. Well that's ok, but now I'm really curious about class D, George Hifi you got a loaner I can try?
Sure a couple you can choose from, you can pick up (i won't post) from North Manly 2100 Sydney, where are you coming from.
Earlier, George gave a list of well respected manufactures of high end components. They all said how class D was inferior and it wasn’t as good as their stuff and yada, yada.
Did anyone stop to think that these other high-end manufacturers are purposely downplaying class D because then no one would buy their overpriced components?
People see two amplifiers in front of them. One is a class A/B that costs $40,000 and the other is a class D that costs $4,000. People will automatically assume that the $40,000 amplifier must be better because the price difference.
High-end manufacturers know people are gullible and listen with their wallets.
@georgehifi, I stand corrected, you are correct. For whatever reason I was under the impression that it was a class D amp. It is not. Well that's ok, but now I'm really curious about class D, George Hifi you got a loaner I can try?
This conversation turns a lot of my Audiogon impressions on their head. People who, I think, believe that great sound qualities can’t be measured are at the same time suggesting that because of inherent measurable design challenges of class D, that no class D amp can sound good. It also seems that more measurement-oriented folks may be coming out against class D because...I don’t know. The latest designs (NCore and purifi) seem to have dampened the IM distortion well into inaudible range.
Nothing to do but listen to the new designs as they come out and try to get rid of our preconceptions. I have a cheap NCore design on order and I’m looking forward to possibly hearing the difference. Given that it is, effectively, a weak AM transmitter, I’m going to move it away from my sources, as that *could* be a source of problems.
I do, but sorry toetap I also go with the views of these 10 top amp designers, before listening to a retail salesman as yourself. https://forum.audiogon.com/posts/1785554
@georgehifi, you really must go and listen to some amplifiers before giving opinions. As @ricevs says there are many factors that add up to influence the sound of an amplifier, just because it is using GaN doesn’t necessarily make it better. This was shown in a recent high end class D comparison were a GaN based amp came second despite being considerably more expensive than the “conventional” class D amp that came out on top. A close third was a class D amp that cost considerably less than the GaN based amp.
We have listened to a number of highly regarded class A/B designs and a particular class D design we use was far better.
You mentioned Soulution class A, we know somebody who has had the 7 series (£50k +) in his system and changed to the same class D amp that won the shootout mentioned and is very happy with the changeover.
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.
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
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.
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