Eric, very interesting. I had similar situation switching from Rowland 102, an early Icepower (200ASC) class D amp, to Benchmark AHB2 class A/B. Rowland was a little bit darkish sounding while Benchmark is vivid and airy with better treble extension. What surprised me the most was the bass extension - much better with Benchmark. I cannot tell if class D sounded worse when cold, since I kept it on all the time, but I remember that it took initially long burn in time (about 400hrs) to make it sound the best. Benchmark is better sounding overall, but it is for 2x more money. It would be interesting to compare Benchmark to class D amp with the same price tag.
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Newer Class D is a totally different animal , in as good as most very good amps
muchmore efficient and much lower in thd. Jeff Rolands Top Digital is Excellent
and uses custom Pascal digital modules with custom input,output stages
The modules are made in Denmark .my Gato 400-S also from Denmark
make a excellent Digital product ,very natural ,Tube like - with tons of dynamics
and musicality, at under $7k for a 400 wpc integrated is a bargain and
a work of art cosmetics wise.i hav3 owned everything from tubes,to classA ,class AB. I am very happy with this amp it just makes good sounding music.
It is more than a bit worrisome that 99% of the opinions one reads
on this forum espouse opinions and have use a blind tested. Can that
even be considered a valid test? Eric mentions he did it blindfolded.
Good for him.
Sanders makes a class a/b 500/wpc stereo amp which sells for
$5,000. Warranty is lifetime. Not that I don't enjoy the Danes
but hey, Colorado is closer!!
I bought raw ICEPower modules and put them in cases as specified. Speakers were customs with data available here:
Yes, indeed, amps sound different. My point was not that Class D was always worse than Luxman, or Luxman better than Benchmark.
My point to the entire post was that we have to move beyond talking about Class D as being inferior and treat them like we would any other amp.
What we talk about are personal experiences, which scientifically we'd call case studies. If you buy solely on scientific studies and discount case studies, including your own experience, you are definitely in the wrong hobby. That's like buying wine based on Ph factor alone.
I didn't say I did a test blindfolded. I said if I were blindfolded I could not tell the difference, meaning, with my eyes wide open, I was unable to perceive a difference between the specific ICEPower modules and a well known linear amplifier, even knowing they were different.
The quality of sound from gear made by Sanders / Coda is not the point of this thread, but I have strong opinions on the matter and would be happy to debate you elsewhere.
To repeat, the point of this thread is not "my amp sounds better than yours." It is that we need to stop using 1990's Class D sound to describe modern Class D. Treat modern Class D amps as you would any other amp and decide what to buy or not based on your own ears.
Audioman mentioned that Jeff Rowland top amps use modified Pascal modules. The only other amps, at least that i know about that use Pascal modules (also modified) are D-sonic amps which I happen to own and can attest that these things are pretty remarkable. Very few people have heard them but after owning these, i see no real reason to go back to AB class.
I agree it is time to except the benefits of buying a 2019 class D amp. For me it was the low price with high price performance. I have enjoyed a Audio Research VT power amp a few years back, but overall it was to rose colored in sound for me and one of the tubes went bad and caused a hissing noise so it went back to my dealer, but i did enjoy it briefly. Since buying my Nord NC1200 I am now completely satisfied, even tho certain members recommend the ICE power Class D amps which i have not heard. Colin at Nord said his NC1200 Signature is his best sounding amp with the ICE POWER being slightly behind. He is also testing the Purifi modules and states they sound good but still believes the NC1200 is the one to own. Colin mentioned he has got some Weiss OP-AMPS which are very good but expensive, they can go in the NC1200, the great thing about the NC1200 is you can change OP-AMPS to suit ones personal tastes or system, Its called OP-AMP rolling.
@laserjock, tested Benchmark ABH2 vs Nord 500vs SST Ampzilla 2 vs Mola Mola Kaluga’s. Results in our opinion from best:
Mola Mola Kaluga’s
The Nord was the most reasonably priced amp at around £1,800 and was good value for money. The Benchmark was a bit better with a more relaxed mid and top but costs nearly double. The SST was definitely a step up from the other two, the sound being much more fleshed out and comfortable to listen too. The Mola Mola just plays in another league and is close or better than some much more expensive class A amps.
Erik:"To repeat, the point of this thread is not "my amp sounds better than yours." It is that we need to stop using 1990's Class D sound to describe modern Class D. Treat modern Class D amps as you would any other amp and decide what to buy or not based on your own ears."
I switched from good class AB amps (McCormack, Adcom and Aragon) to my first class D amp(a ClassD Audio SDS-440-CS stereo amp) about 12 yrs ago. I was so impressed I replaced all my class AB amps in my combo 2-ch music and 5.4 HT surround system with class D amps soon after(an Emerald Physics EP-100.2EP for my center and a pair of D-Sonic M3-600-M mono-blocks for my mains).
I perceive my class D amps main characteristics as having a very high Signal/Noise ratio resulting in a dead-quiet background noise level and a high level of detail, very good dynamics, extremely low distortion levels, especially good bass response with a detailed but very smooth midrange and treble and overall a very neutral presentation with nothing seemingly added or subtracted from the inputted signals, like the audio ideal of a 'straight wire with gain'.
Class D amps also have significant and numerous non-audio benefits such as small size, light weight, relative affordability, cool to tepid operating temps and high electrical efficiency both during use and at idle.
I understand the appeal of all the various amp types and know excellent sound quality can be attained using any of them. Of course, we should all just use the amp we like best. I choose to use class D amps in my system due to a combination of sound quality and non-audio benefits.
Mola Mola? That is some name for an electronics manufacturer. The problem with class D amplification is that there is a very broad range of quality. It can be a very cheap way to build an amplifier of mediocre quality with a high school electronics degree and make a lot of profit.
Then there are the good ones like the Rowlands that are faster and have high quality power supplies. I had a pair of TACT amps that were sort of class D. They were pulse width modulated sampling at 90 meg. They sounded very nice. I used them to biamp my Divas. Unfortunately they struggled to drive my Acoustats and would keep tripping their protection circuits so I moved on. I think Lyngdorf still uses the design. I have not had the opportunity to listen to a lot of class D amps so my opinion lacks for sample size but I have not yet heard one that sounds as good as a Class A amp. Hopefully some day that will change as I see no great advantage in all that heat and high electrical bills not to mention that big heat sinks are expensive.
If you have ever read the works of Nobel winning psychologist Daniel Kahneman, he devotes a lot of brainpower and ink to proving that people develop a process of thinking that usually makes it very difficult for them to accept change. Often, completely unbiased analytical data doesn't help with allowing someone to open their minds to the possibility that some process or product may be better. Therefore, we may be talking about the comparative aspects of Class D sound for a while.
Six years ago, I bought a Crown XLS 2000...a $500 Class D amp based on a TI chip. It sounded darn good, solid and deep low end, big soundstage (width but with minimal depth), dynamic and decent but sibilant midrange and top end.
I replaced that amp with a Class A/AB Parasound Halo. It was better in every respect...but still, pianos, trumpets and a few other things didn't seem quite right (and obviously, it could have been the speakers, dac, preamp, wires, etc.)
Then, two months ago I replaced the Halo with another Class D...which should elicit the question WHY a Class D of all things. For exactly the reason that erik suggested...there isn't really a reason to be talking about amplifier classes so much anymore.
At any rate, I bought a 2Cherry from Digital Amplifier Company. If you go to their website https://www.cherryamp.com/dac-home you will see that they are building Class D amplifiers unlike anyone else...bandwidth to 150kz...switching frequencies up to 2mghz...and they don't use modules from anyone else. Their owner/engineer Tommy Obrien designs his own circuits and the builds his amplifiers from discrete components. His stated goal is for his amplifiers to sound like nothing. (Sounds a lot like the specs and statements from the well respected Class A and Class A/AB guys)
Tommy doesn't do paid advertising with anyone so one might assume that the professional reviews he is getting from the magazines might be a little more (skeptical, critical, harsh, etc.) less supportive...but in fact, they love his amplifiers.
Let me say this about the 2Cherry...in comparison to the Halo it replaced...What "shocks" you right away is the incredible level of transparency/clarity that seems to lift a fog that you didn’t know was there which brings the music alive. There is no sibilance, no brightness, no harshness, no artificially pumped up midrange and top end. This amplifier brings you into a detailed, layered, powerful yet delicate soundstage with emotional involvement similar to a live performance.
I think we might all agree that the sound that moves us and the amplifier that brings us that sound is a personal preference...you prefer X and I prefer Y...and one of the beauties is that we have choices. I'm with eric on this one; there is no longer a need to talk about Class D vs other classes...instead focus on what sounds best in your system and be open to the idea that it just might be a Class D amplifier.
I'd like to offer a correction. I said:
I didn't say I did a test blindfolded. I said if I were blindfolded I could not tell the difference
But actually, I kind of DID say that. Sorry.
What I meant to say was:
"I knew which amp was which, and even then I could not tell them apart."
Apologies for forgetting what I just wrote.
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.
Just a guess, but the switching times of transistors vary as a function of temperature, which may take a relatively long time to stabilize in a class D amp due to the low power consumption. And perhaps what is occurring during the 2 to 4 days is that the turn-on and turn-off times of the transistors which supply current to the output from the positive DC rail become more closely aligned with the corresponding switching times of the transistors which supply current to the output from the negative DC rail. Thereby reducing or eliminating "shoot-through" or "dead time" that may occur during those transitions, when both groups of transistors may for a brief instant be simultaneously on or simultaneously off.
On another note, Erik, as others have said thanks for yet another very interesting thread.
I recently auditioned Bel Canto Ref600 M's for a good bit of time in my system and was super impressed. These are wonderful amps that compete with any amps under $10K regardless of topology;
My speakers are Dynaudio Contour 60's; Amps in my rig over the past few months: Pass XA30.5, Pass X150.8, Pass X250.8, Luxman 509X;
All have various strengths and such and one does not necessarily "blow away" the other; The Bel Cantos gave me the sense of a wide open window into the performance and seemed to be very complete. I remarked many times about how beautiful and real voices sounded. Excellent grip of the (4 ohm nominal / medium sensitivity) Dyn woofers as well; If they had any weaknesses I did not hear it. Incredible value.
Great post and very interesting about the on-time;
I did notice the amps sounded most excellent after about 30 minutes of on time. I did not hear any further changes after that.
Great post snapsc!
Your description of the performance characteristics of your Digital Amplifier Company 2Cherry class D amp to what I experience with my D-Sonic M3-600-M mono-block class D amps are remarkably similar.
I also found your discussion on the psychology of change very interesting and relevant. Having been a manager of large groups of individuals in a constantly changing and fast paced environment, I'm well aware that individuals have varied, wide ranging and evolving reactions to change. Typical reactions progress from skepticism and firm resistance to reluctance and mild resistance to acceptance and little resistance to education, experience and complete understanding leading to no resistance and the eventual embracing of change.
Individuals will vary in their initial reaction to change which will dictate their beginning stage in this evolutionary progression of stages of human reactions to change. The most successful individuals learn to expect constant change, look for opportunities where change would be beneficial, seek to completely understand the change and eventually embrace constant change.
I should point out that these stages of individuals' reactions to change I described above are just my thoughts and recollections spurred on by snapsc's mentioning of the psychology of people on change. I've never read any of Daniel Kahneman's writings, or any writings, on the psychology of change. My thoughts are based on the behavior of employees who worked with me confronted with change and are a summary of what I learned.
The presence of good quality class D solid state amps, as an additional option to the more traditional tube and solid state amps, was a change to home audio that I believe follows the normal variance pattern individuals demonstrate in their reactions to change in general.
My first experience with a class D amp in my system was about 12 yrs ago when I bought a ClassD Audio SDS-440-CS stereo amp (220w/8 ohm 440w/4 ohm,15lbs with a linear power supply and Texas Instruments class D modules) for about $500 to drive my pair of Magnepan 2.7QR speakers (4 ohm and 86dB efficient). It was about 1/5th the size and weight of my prior amp, a class AB Aragon 4004 MKII, but still delivered a bit more power (440w/ch at 4ohm vs 400w/ch).
I paired a VTL 2.5L preamp with a set of 4 NOS Mullard tubes with this new class D amp and was amazed by the performance even straight out of the box with zero run-in time. Of course, it just sounded better with run-in time over a few weeks. The outstanding characteristics I quickly noticed were the extremely low background noise level, the high degree of detail and the best bass response I had ever heard up to this point from the 625 square inch dipole bass sections in each of my 3-way Magnepan speakers. Taut, detailed, natural and impactful bass that I had no idea these speakers were even capable of producing. I think this must have been a result of the extremely high damping factor (>1,000) that this little class D amp possessed.
The midrange and treble response was also very good, smooth, detailed, natural, with no hint of shrillness or harshness and with a well defined, solid and stable soundstage illusion projected. I realize that my tube preamp likely assisted in this very good performance but the combination of the VTL preamp with the class D amp sounded at least equal in sound quality to the combination of the same preamp with my previous class AB Aragon amp.
Given my great first experience with a class D amp, I was surprised to discover that some posters on Agon at the time and since have claimed to hear deficiencies in the sound of class D amps that confused me since I was completely unable to detect any of their claimed deficiencies such as 'harshness and shrillness in the treble', 'a lack of high frequency extension and air' and 'the carrier frequency being too low and causing sonic anomalies in the audible range'.
12 yrs later and owning several additional class D amps and listening to many more, I am still unable to detect any of the continually claimed deficiencies in class D amps. I've come to the conclusion that either these are false claims or that some individuals, for some currently unknown reasons, perceive deficiencies in the performance of class D amps that others do not perceive. An oversensitivity or allergy to class D sound.? I'm just trying to figure out this dichotomy between those that love class D and those who don't like it at all.
It’s not the class D (ICE in this case) that’s the issue. It’s the sucky SMPS’s that are the problem. I have a pair of (when available) $25k Acoustic Reality Thaumaturges, it is one of the finest amps I’ve yet to hear and own and that is a very long list. I also had a pair of the Acoustic Reality Ones (if I recall the model correctly), they were about $6k per pair and had some custom mods performed by the manufacturer to take them even higher than stock. The One’s used a SMPS and like all SMPS’s I have ever experienced, the moment they are plugged in anywhere near my system, the whole system TANKS AND SUCKS!
I sold the One’s, they were HORRID! I’ve owned the Thaumaturges with their linear power supply for nearly 10 years now. The only amps I’ve preferred to them are my Graaf GM 200’s and my Graaf Modena, maybe my former Tube Research Labs GT 200’s but not sure about that, been a long time since I owned the very impressive TRL’s.
Class D can be wonderful but in my experienced opinion, if it has a SMPS just forget it! Even my Mac Mini music server SMPS killed the sound, it now has a linear supply.
Even my router LOL!
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.
If the former, I am certainly not stating that all ICE implementations are the same or that they would all be good if not but for SMPS’s.
I’m saying SMPS’s ruin everything I’ve ever heard including the Studer A820, which is one of the reasons I passed on that deck when looking for a tape deck (it has multiple SMPS’s). It’s also one of the main reasons I sold my Technics SL 1200 GAE.
If you are saying you can live with SMPS’s well then we just differ in how we hear which is ok.
Class D can be wonderful but in my experienced opinion, if it has a SMPS just forget it! Even my Mac Mini music server SMPS killed the sound, it now has a linear supply.All highly rated Rowland class D amps have SMPS. When done properly SMPS is much quieter than linear power supply, not to mention line and load regulated while linear supply is not.
Rowland uses SMPS even in preamps, where efficiency is not important, just because they can be so quiet. Another example is Benchmark. Their products, known to be extremely quiet, contain SMPS. They were able to lower noise by 10dB in their DACs just by switching from linear supply to SMPS. AHB2, an extremely quiet power amp uses SMPS.
"Linear Power Supply", in fact, is a very primitive unregulated switcher operating at 120Hz and switching at max voltage, charging output capacitors with narrow current spikes of very high amplitude. It produces 120Hz ripple as well as very narrow switching spikes, both very difficult to filter out. Also, many believe that transformer has to be heavy to deliver a lot of current. It is all matter of frequency. Small 1" ferrite transformer operating at 100kHz can deliver as much power as huge transformer operating at 60Hz.
Yes, SMPS can be very bad, especially when in cheap/crude computer power supplies but can also be wonderful when done right. It is funny that anybody can think, that SMPS is not good enough for class D, while class D is modulated SMPS.
Yes I know SMPS’s are inherently regulated and can be very quiet but the crap noise (RF) kicked back is VERY VERY hard to stop and it fouls up (at least for me) everything I’ve ever heard them in when it comes to a high end system. A switching amp and SMPS are not the same thing.
I have owned amps as stated before with similar ICE modules, one with linear, the other with the SMPS from the same manufacturer. Forget even running a signal through an amp with a SMPS, try this experiment if you have another amplifier with a linear supply. Power your system with the amplifier (linear or switching) that has a linear supply. Listen to a well recorded passage. Now take a device, amp or anything else with a SMPS and plug it in near your audio system. Now listen to the same passage. If you hear no difference, your experience is FAR different than mine.
It’s the type of noise that is so damaging with a SMPS. It’s akin to odd order harmonic distortion. Large amounts of even order harmonic distortion can be tolerated and sometimes even enjoyed, but odd order harmonics orders of magnitude lower can completely wreck a system. SMPS manufacturers and users of them like to tout the noise levels but what they always fail to discuss is that the noise in linear supplies is MUCH MUCH more benign that the noise from a SMPS.
Manufacturers like SMSP’s because they are cheap, and don’t weigh anything, thus it’s cheaper to ship product. Some years ago, and I’ve mentioned this before, John Ulrich and I were discussing if he should stop using the big toroidal based power supply in the Spectron amplifier in favor of a SMPS. I successfully talked him out of that possibly disastrous path. What was his reason? Sound? No. Noise level reduction? No. The reasons were cost and primarily weight. He knew it would hurt the sound but he told me his shipping cost to the Far East were very high and that was the main driving force behind the desire.
Ed Meitner tried it with the Bidat as an option. It was horrid! They dropped the SMPS option almost as quickly as they came out with it and no, I don’t care for any of the new EMM Labs gear with the SMPS. Note that when Andreas left EMM and started Playback designs he went with a linear supply.
Again, if you don’t hear the detrimental effects I hear with a SMPS that’s good for you.
If I plug my noise sniffer in near SMPS that thing goes off like a Geiger counter near Chernobyl, not so much with linear.
Ok, enough, I didn’t mean to hijack this and I apologize to the OP, I was just trying to answer comments that came my way.
We return you to your normal programming :)
Switching amp (class D) and SMPS IS the same thing. In fact class D was discovered when engineers tried to show how responsive SMPS was by modulating it with music. I would say that it should be more difficult to build good class D amp than good SMPS since class D amp has to maintain linearity while SMPS only keeps voltage steady.
As for the noise in amplifier - it can be easily measured. I currently listen to music coming from my Benchmark AHB2 power amp driven by Benchmark DAC3, both powered by SMPS, and it sounds wonderful. Both received the highest Stereophile ranking in "2019 Recommended Components".
Linear power supply has to have a lot of output capacitance to keep voltage steady under the load and to filter out 120Hz ripple. These huge, inductive capacitors are in series with the speaker (circuit closes thru them) compromising sound.
Here is interesting FAQ:
It mentions AHB2 (powered by SMPS), perhaps the quietest power amp ever, with 132dB S/N.
I don't question your bad experience with SMPS understanding where it might be coming from, but keep your options open. Jeff Rowland wouldn't compromise his business by completely abandoning linear supplies and making everything with SMPS if there is something inherently wrong with it.
One more thing (as Columbo said): SMPS are not cheap. Cost of high quality SMPS has to include high cost of development. Rowland’s supplies deliver thousands of regulated watts operating at 1MHz (and components doing this are not cheap either). I couldn’t believe it is even possible, since most of switchers operate at 1/10 of this frequency. I can give you a simple reason (other than complexity) why many manufacturers decide to go with linear supplies. It is because there is still a lot of people thinking like you. There was similar prejudice against all class D amps not so long ago. Many believed they are good only for subwoofers. I would advise the same as Eric did - don't look too much into technicals like class of operation or type of supplies, but listen instead.
I visited Cherry's web site yesterday alerted to this amp by another threat. I would love to hear a mono pair of the Megachinos. The web site is not very informative as to what type of sampling he is using PWM or PCM and he does not mention how fast. 2 meg is mentioned above. The Tact and Lyngdorf amps sample at 9 meg PWM. Those amps were/are crystalline but do not have the best bass and have trouble with difficult loads. For a system that uses subwoofers they are first class driving any speaker 4 ohms and above. You had a choice of digital or analog inputs.
The Cherry amps are a nice clean design without unnecessary filigree. The only thing I would like to see is a digital input that accepted 192/24.
Many if not most of us are using digital sources and processors myself included. I actually digitize my tube phono amp. Analog inputs only forces me into two more conversions that could be avoided. Converting 192/24 into whatever the amp is doing should not be that hard.
If you look at pictures of the Megachino you will see several large ICs. The analog circuits may be discrete but the digital ones are certainly not. He does not mention what chips he is using and why. You could say he does not use anyone else's class D module. I like that but would want to know more. He does give you a 30 day home trial. If I were looking for new amps I would give them a spin but I am not and would not do a home trial without the possibility of a purchase.
Humans are very change resistant and risk adverse with few exceptions.
They are also egocentric particularly males. It is cool to see those who manage to break away from this like Ford, Edison, Musk and many more.
Thanks to the OP.. Heard some class D a decade ago, they sucked. Heard some in the last year that were excellent.. Tech changes much faster than the conversation in audio. Consider that class A purist still claim an advantage over A/B due to notch distortion in early A/B designs. The notch distortion was solved in good A/B designs decades ago, but the stereotype is still talked about today. Same with class D today. People will talk about the original issues with class D for decades after the tech is equivalent or even after an improvement has been made. Imho. class D has became competitive in performance and sound quality today. In a couple more decades the stereotype might start to fade away.. Hearing/comparing some of the latest class D for yourself is the only way to know the truth of today. Agree with the OP.. Don't limit your choices at this point in amplifier design, based on old news.
A couple more things about the cherry amps that I didn’t mention.
1. Most of their more detailed information seems to be located on their audio circle page... link at the bottom of their web page.
2. You will find that the are willing to sacrifice some S/N for feedback and electronics changes that they perceive results in a more colorless sound.
3. The cherry amps have an absolutely black background.... silence through my loudspeakers with the volume turned up full.
4. They solved my piano, sax, trumpet and drums tone issue... they do tone beautifully
Hope this clears a few things up.
From my experience with several Class D amps, newer Class D amp designs in general seem to have very effectively resolved the noise issues that can otherwise be associated with SMPS. I’ve seen this with my Class D amps ranging in cost from <$100 to those going for several thousand dollars. Does not seem to be an issue anymore if done right. Not so much the case as recent as just a few years back though I’d say.
Here is an interesting take on Class D amps: I picked up a pair like new Anthem M1 Monoblocks from a very wealthy guy who decided that he just had to have a pair of Levinson 53’s at some god awful price point. I got a really nice deal on the pair in mint condition and with later serial numbers, consecutive of course. I put them into service against my Parasound A51 Halo which is 400 watts per channel at 4 ohms vs. the 2000 watts per channel of the M1’s (when fed with dedicated 240V mains). It was love at first sound; these things blew away the A51 in all respects, it was no contest. I have not used the A51 in two years now, its occasionally used as the power amp for a center channel when I run the TV.
I spoke not too long ago with the guy who sold me the amps and asked how he’s enjoying the $35K amps he bought and he told me he made a major mistake selling me the M1’s, they are actually better than the Levenson’s! That really surprised me, but then again, it doesn’t as I have not heard anything as beautiful as the M1 monoblocks..... Class D of course