I love my cherry plus amp from digital amp company. Is it the best? No, but for the money it is very very good
The Truth about Modern Class D
All my amps right now are Class D. ICEpower in the living room, and NAD D 3020 in the bedroom.
I’ve had several audiophiles come to my home and not one has ever said "Oh, that sounds like Class D."
Having said this, if I could afford them AND had the room, I’d be tempted to switch for a pair of Ayre monoblocks or Conrad Johnson Premiere 12s and very little else.
I’m not religious about Class D. They sound great for me, low power, easy to hide, but if a lot of cash and the need to upgrade ever hits me, I could be persuaded.
The point: Good modern Class D amps just sound like really good amplifiers, with the usual speaker/source matching issues.
You don’t have to go that route, but it’s time we shrugged off the myths and descriptions of Class D that come right out of the 1980’s.
I’ve had several audiophiles come to my home and not one has ever said "Oh, that sounds like Class D."
Having said this, if I could afford them AND had the room, I’d be tempted to switch for a pair of Ayre monoblocks or Conrad Johnson Premiere 12s and very little else.
I’m not religious about Class D. They sound great for me, low power, easy to hide, but if a lot of cash and the need to upgrade ever hits me, I could be persuaded.
The point: Good modern Class D amps just sound like really good amplifiers, with the usual speaker/source matching issues.
You don’t have to go that route, but it’s time we shrugged off the myths and descriptions of Class D that come right out of the 1980’s.
288 responses
When, oh when, will people stop commenting on components and wake up to the fact we are building systems? Take a speaker with slightly soft top end and marry to a slightly zippy amplifier and the combination could be closer to the ever unattainable perfection. Equipment reviews are sometimes are funnier than the comics! |
Vladimir Shushurin (Lamm) Bingo |
We better put up the question again to what this answer above relates to, which is: " Is Class D competitive with linear designs in sound quality, and if not, will it ever be?" Cheers George |
@stereo5 - I’d suggest you make your specifics known. What Class D and what are you comparing it to? Because the ICEpower I’m listening to sound nothing but warm. The NAD D 3020 sound a touch brighter, but not unpleasantly so. There’s nothing in your original statement specific enough for me to believe you are being sincere. If you are, state your experience. I could say the same about tubes. "Tubes are not high end, but maybe someday..." |
@erik Squires...……………………………... A good friend has the Merril Audio Class D monoblocks. Do not know model number, but they were painted very red. I find them dry and tipped up on top. I tried the Wyred4Sound Class D stereo amp in both of my home systems. I had it in my systems for 2 weeks. I left it on 24/7 and played the Isotek burn in cd for 10 days straight, 24 hours a day. I didn’t like the presentation one bit. Actually, it sounded better before all the break in, but not better in a way I would have kept it. Back it went. I heard a Devalient, and kept asking myself what all the fuss was about. I heard the MBL integrated (the one Stereophile loves) at the RMAF, hated it. My wife said it sounded shrill. My son has a NAD 3020 integrated Class D amp (the first one) . The rest of his equipment I gave him, a pair of Kef LS50 speakers, Audioquest cables and speaker wire, my old Sony SCD777es SACD player and a Magnum Dynalab FT11 tuner.. I can’t stand listening to his system, way too bright for these old ears. My son thinks it sounds clear, it just gives me a big headache. I have heard a couple more class D amps in stores but not for long listening sessions. Sorry, I just do not care for it. Does that make me a horrible person because I don’t like them? I enjoy the lush romantic sound I get from Mac and since I am spending my money on it, what I like counts (to me). |
Does that make me a horrible person because I don’t like them? I enjoy the lush romantic sound I get from Mac and since I am spending my money on it, what I like counts (to me). Absolutely not. But the specifics help everyone understand where you are coming from and what you are comparing to, and give a lot more insight to your story. My NAD D 3020 is hooked up to a pair of Monitor Audio, which are much more laid back, which may explain the difference in appreciation for it. :) As I myself have noted, if I had all the $$$ and space I’d buy some CJ which are going to be even more euphonic than your Macs. I still like my ICEpower monoblocks though. I certainly could not point to them and say "look, Class D sound!" Thanks for sharing, Erik |
Which do you think would sound better:
The continued development of quality class D amplifiers has opened up the possibility of dedicating an amplifier to each driver in a speaker. The continued development of DSP and associated software has opened up a way to tailor crossovers, equalization, and phase response to specific drivers and speakers and the room they are playing in. CD transports, DACs, preamps, interconnects, separate amplifiers and speaker cables will all be obsolete in five years. They are the Dinosaurs of Audio left over from 1958 technology. The future of Audio is visible in the KEF LS50 Wireless, which does away with everything but an active speaker with a DAC and connectivity. Make the speaker bigger, with better bass, and add DSP room correction software, and you have the audiophile system of the future. One of the most difficult problems of speaker design is the crossover. DSP and active speaker technology is affordable and solves that problem. The biggest problem for today’s audiophile is speaker/room integration. DSP room correction solves that problem. Will you encase your Dinosaur audio technology in amber and stride confidently towards the future, or will you wrap yourself in $10,000 speaker cables and yell "Over my dead body!!"? |
@phomchick - well it's a good suggestion, and the cost of Class D can make it possible to create a separate amp for each driver and use an active crossover. But you're still forgetting the challenge of Class D to reproduce the ultra high frequency "air" that a good Class AB amp will do. I am in the same camp as stereo5 in that I have not heard a Class D amp that really "sings". Granted, they are so extremely clean that it's insane (I have actually been told that sound engineers like to use them because they can hear individual instruments when doing the mix for a record), but every Class D I have heard leaves me wanting more. It just doesn't have that extra edge of "life" that Class AB gives you. |
It does not come down to like or dislike as much IMO as it comes down to the system and comparisons. I have a friend of mine who has Class-D amps and fells like many that they compete in the market for sound quality and price. He has told me that same thing about many other components he has owned. It is only when he finally hears something that presents a difference in his system that he recognizes the sound differences and why. Until he hears that, he feels he has something that is very good. I guess I need to get him the Class A amp my partner built recently to see if he hears any difference. Until then we both won't really know if he is correct or not. Happy Listening. |
There are certain things I cannot argue with. Personal choice for specific amplifiers and speakers. That’s fine. My argument was not "you should like Class D more than your favorite" but that Class D as a whole is just as good as capable and musical as any other solid state amps, with a lot of the same pitfalls. The technology has in fact arrived for good, and we are better for it. |
We better put up the question again to what this answer above relates to, which is: I believe it may be someday but it isn't yet to my ears. I've heard the Parasound Halo Integrated take the Devialet Pro monoblocks to school. The new NAD N-Core based amps sound no better than class D of 15 years ago: cold, analytical and fatiguing. Same for the hybrids I've heard. I'll continue to give new designs a chance, but I've yet to encounter one that sounds as smooth/listenable as a halfway decent class AB amp. I think some audiophiles just don't hear the digital-like character that most, if not all of them exhibit. |
Unless you have heard the very latest and best class D amps then you have only heard history. The brand new Merrill amps have way more musical and detailed sound than the previous Hypex Ncore based amps. You can read some comments on their site and more info will be here shortly. The brand new Nuprime monos are suppose to be killer. My about to be released $1000 and $1900 tweaked ICEege amps are seriously great sounding. My own reference amp for the past 5 years is a class A amp designed by myself. It is dual mono and super, super pure and tweak in all ways....only two fets and two resistors in series with the signal per phase. Well, the ICEedge prototype is overall better.....better in most every way.....and I have three more things to try on the proto amp. I don’t want to go back to my class A amp. Here is something to ponder......All connectors suck....and I mean big time! I have hardwired my amps to my x-over and speaker drivers for years but only in the last year did I remove the connectors on my interconnects. I had no idea how bad they were. I will never have any connectors (except AC) in my system again. If you have connectors on a warm or colored system then the system still might sound musical. However, having connectors on a pure "straight wire" system will bring agony to the listener. Connectors sound like bad class d or digital....really....grainy, compressed, Aharmonic, rolled off......just bad. My new amps will have my binding post bypass system where the binding post is used only as a clamp, that clamps your speaker wires (hopefully without connectors) directly to the wires coming out of the amp. I will also have optional hardwired interconnects on my amps and also have optional hardwired short pigtails hanging outside the amp that you can solder your own wires to. All these things have never been offered on any amp before (except for my previous amps that had my binding post bypass system). This is just the beginning. I predict that in 2-3 years Class D will be so close to pure straight wire that all other amps will then be history except for those addicted to coloration. Class D will also become even more efficient and smaller and cheaper so we will all win on all counts. The class D revolution has started. |
I have had the opportunity of trying in my own system a late pre-production of the brand new Merrill Element 118 monos... All amps of the new Oganessom series have class D output stage circuits totally designed in house by Merril... They employ Gallium nitrite transistors switching in the Mhz range. In spite of the units that I demoed being pre-production, and not yet sporting all the circuit details of the very final implementation, the tone of the monos was absolutely delectable for all parameters I an think of.... From delicacy and extension of treble, to the complexity of the midrange, to the depth and tunefulness of the bass... And let us not forget a quite phenomenal authority, staging and imaging. Element 118 were immersive and mesmerizing, with a complex resolution and musical tonality that I have experienced only in rare cases. The element 118 prototypes seemed to rank with flagship devices from some of my favorite brands, such as amplifiers from Soloution, the ARC reference series, and my own Rowland M925 monos. On the other hand, if what you seek is a classic warm tube sound, none of the above will do.... It is not a matter of such designs as the Merrill Oganessom series, Rowland M925 and Daemon, or even the class A/B Soulution amps, or even the reference seiries ARC tube amps. "not being there" yet for a reason or another.... Rather, the designers of any of these devices are not aiming at the slightly euphonic warmth of the classic tube sound. While general goals at Rowland, ARC, and Soulution include, amongst other parameters, harmonic complexity and minimization of intermodulative distortions in the treble, they aim to maintain an even treatment of harmonics across the spectrum, without preferencial emphasis of any particular region of the audible band. But designers achieve their flagship goals with very different sophisticated strategies, which employ Tubes at ARC, class A/B output stages with Soulution, NCore NC1200 or Pascal X-Pro2 in Rowland, and completely custom design of class D output stage on the Merrill Oganessom series. Bottomline... Do not get fixated on topologies, and keep an open mind. Keep auditioning to amps of different tonality, designs, and vintage... You never know what might capture your heart *Grins!*
Remember that the worst enemy of audiophiles, and humans in general, is what is sometimes called the false induction step... That is judging an entire class of complex objects based on characteristics of some small number of samples. Even less reliable a technique when the samples are out of date or otherwise obsolete.
Saluti, G. |
@mdeblanc Your Cherries replaced a J2? That says something. And you are “just” using the Desktop 60v amp Version. I have an Ultra Cherry coming to me soon. For those who may not know, The Ultra is a hybrid SS/CLASS D amp with an 1800w toroidal transformer for extra headroom and transients. SNR is still 116. Built by Tommy O’Brien of the Digital Amp Co in PA. He is the quintessential independent owner/engineer/designer that sells only via word of mouth and his own thread on AudioCircle, no adverts. He does some custom jobs too. |
@phomchick all good points. But I would argue 2 things, that although built in DACs with Built-in DAC with built-in amps-in-speakers May very well @be the future”. But that will be more of a commercial product in the future than an audiophile product. Mand the Kefs entwined are good, but not great cans same for all the Dynaudio all in one speakers I’ve heard. Severely limited in many respects. Sound. Precision. Pray. Musicality. Power. Nuance. And my 2nd point? Well, there is no damn fun if the system and speaker do everything for you. Again, that is a commercial product, not an audiophile product. If DSP is going to do everything for you, then you don’t learn anything about how the sound waves and sound effects can be managed in your room with your own knowledge and know-how. Boring. |
I suspect one reason for the vastly different takes on Class D is a matter of physiology. People's HF perception vary dramatically, and something irritating to one person may not register much for another. This is particularly true w.r.t. gender - women tend to have superior HF acuity, and my wife can spot treble issues almost instantly. Faults that take me a while to pick up will drive her out of the room in a heartbeat. (She can't pick up on bass notes for her life though!) I haven't heard much of the latest SOTA Class D, but I did get a brief listen to the Devialet 250 recently. I thought it sounded quite good, smooth and full with killer bass. There's something about the way Class D does low frequencies - not only the power, control and definition of bass notes, but also the evenness of response. Traditional amps sound lumpy by comparison, though this might be more a function of the switching supply than the actual amplification circuit. (Chord amps are Class AB but with a switching supply, and have a similar evenness of response.) I still have the nagging feeling that the Devialet doesn't quite have the air, openness and dimensionality of the best linear amps, but I'd need a more careful audition to ascertain that. In any case, I'm going to seek out some Class D for review - I have my eyes on an nCore implementation, and will look for something based on ICEPower 1200AS2. Recommendations appreciated. Cheers, TAWW taww.co |
@1graber2 But that will be more of a commercial product in the future than an audiophile product.... Severely limited in many respects. Sound. Precision. Pray. Musicality. Power. Nuance.There is no reason an active speaker cannot be an audiophile grade product. We are at the beginning of this technology. There is Dynaudio, Genelec, Kii, KEF and very few others. I believe I saw an interview with Andrew Jones where he said ELAC is working on an active speaker, and the new PS Audio AN speakers will be partially active. Of course, the best Pro monitor speakers have been active units for almost 20 years. This technology will rapidly improve. And not only is there no reason that active speakers can’t be audiophile grade, they allow elimination of passive crossovers and the adoption of DSP crossovers which can provide much better sound -- offering solutions to driver equaliztion and speaker time alignment as well as room correction that you can’t get any other way. Not only will active speakers with DSP achieve audiophile quality, they will set the bar for the highest quality. And my 2nd point? Well, there is no damn fun if the system and speaker do everything for you. Again, that is a commercial product, not an audiophile product. If DSP is going to do everything for you, then you don’t learn anything about how the sound waves and sound effects can be managed in your room with your own knowledge and know-how. Boring.I can’t argue with that. I bought my last preamp in 1982, and my last amplifier in 1989. Since 1990 I have owned three DACs, but until recently the same pair of speakers over that span, and no exotic power cords or fancy speaker wire. (But I have bought a ton of music). If your enjoyment of this hobby comes from flipping equipment in search of synergy and nirvana, you probably won’t be that interested in active speakers. But if you are more interested in actually achieving synergistic audio nirvana, why not join the future and let the manufacturer do it right? And to finish and anchor these musings in this thread, Class D amplifiers are one of the main technologies that are enabling the next generation of active speakers. |
There is no reason an active speaker cannot be an audiophile grade product. We are at the beginning of this technology. There is Dynaudio, Genelec, Kii, KEF and very few others.I sat in the same seat as the presenter used to tune the $14k Kii system from, and listened to 2 known songs that I had with me, and I was outter there. To my senses it was like a surgical knife dissecting the music, that’s the only way I can describe it. The same happened at the Uno ZERO 1 XD demo. Maybe the future, but not yet. Cheers George |
@phomchick what I mean is that the active speakers with D amperage are barely getting sold compared to non active speakers, because they still severely lag behind non active speakers in sales and use. (Except younger folks who find commercial all in one products satisfactory). Therefore, foretelling a utopic all in one Class D speaker in the audiophile community in the near future, IMO, is way way overly optimistic. I mean, we can’t even get George to accept Class D even at its simplest face value! :) |
@erik_squires helomech -Maybe you didn't read through my other posts in their entirety, but no, I've heard many class D amps I didn't like, including but not limited to Devialet, NADs new M class, the Rogue hybrids, Bel Cantos, Audio Alchemy, Peachtree Novas and countless mobile audio amplifiers. I know I left off a few, but anyhow, the one trait they all shared was a sort of analytical (maybe "sterile" is a better description) presentation. For me, they just suck the soul out of music. One reason I no longer listen in my car - has a factory "premium" system powered by class D. |
I mean, we can’t even get George to accept Class D even at its simplest face value! :) I do accept it, but not in competition to hiend audio yet, they make great bass/upper bass amps so far. And I’ve said it all along I’ll be the first to dump my stinking hot, heavy, inefficient, boat anchors. When they’ve got rid of their problem/s, that Technics with the $30k SE-R1 have semi addressed with their 1.5mHz switching speed power amp, 3 x times higher than what’s around at present, then the (switching noise) output filter can do it’s job properly without effecting the audio bands upper mids and highs that so many hear, and owners can't!. I see threads like this "looking for the truth" started as a "reach out for confirmation" from owners who know their Class-D’s are not quite right, but can’t bring himself to go back to linear, almost like begging for forgiveness, for what they have done and everything will hopefully be fine. Cheers George |
Many here know I replaced 2 Emerald Physics 100.2SEs with an Audio Alchemy DPA 1 HYBRID stereo amp, but at the time I was using a Hattor XLR passive pre that George pointed out was also a impedance mismatch. But when I replaced the Hattor with the Audio Alchemy DDP-1 DAC/Pre that the music came together in amazing ways (sonically neutral and 3D) . It was only AFTER listening to them that I was made aware of The Absolute Sound review in March of 2016, comparing them to the SOULution amp/pre. This combo revealed abilities in my Emerald Physics KCIIs, tht allowed me to eliminate my 2 SVS powered subs! The AA combo MSRP is $4K. I am still writing on the external power supply |
" I see threads like this "looking for the truth" started as a "reach out for confirmation" from owners who know their Class-D’s are not quite right, but Hello George, have you perhaps caught a sudden chill? I, like Erik and several others use our ears.... We need nor seek confirmation for the devices and the music we love. Let alone seek "forgiveness" for our anathema... Man, you do need an icepack on your brow today... Or would it be an ICEpower pack *Smiles!* On the contrary, as mentioned so many times, I invite you to get "out of the house" just a bit.... The musical air is amazingly refreshing today... You might even catch a lovely class D breeze. To the contrary of the trite urban legends circulating in old and stuffy audiophilic houses, There are some class D amps that make wonderful music.... Provided one cares taking a good open minded listen to them. In addition to the ones that Erik and I already mentioned on other threads, I recommend a good audition to the newest Merrills Element 118, 116, and 114. BTW, I remember no more than one year ago you advocating that the day of class D would come once designers adopted Gallium Nitrite transistors switching at 1.5Mhz.... But now that appears to be a moving target... As the new Merrills are using such technology, you are changing your dirge already.... And just to make sure you can lament for a few years more, while remaining a staunch paper-bound audiophile,your latest goal is a onetousand-fold Ghz range... Once that boundary is finally crossed, I am confident that you wil pine for a brand new 1K-fold switching frequency leap into the Terahertz range... Meantime, you will still be suffering from never-ending "Princess and the class D pea" syndrome, whilst pouring smilingly over that ever-reassuring old PDF by Martin collom from the 2008 munich Show, where the old trombone from HiFi Critic had not even noticed that he had already missed the train *Grins! G.
|
@abasia good question, and one I have asked earlier when I was thinking the same thing ... to to avoid some unnecessary quibbles, we probably should have established some parameters for Class D in terms of quality r/t: 1. Price of the class d amp, and 2: perhaps overall system cost, assuming some reasonable sense of equality (price, performance) b/w the main components in the system Examples: 1. E.g., for the price of the Class D amp alone, at what Price point would the GENERAL price break be? b/w a good Class D and one that the unsatisfactory Class D amp. $1000 ? $2000? $3k? And so on and so forth. E.g., “even”George has said he finds Class D acceptable at the 1.5 MHz switching speed. How much are those SE-1s? —> Same question for everyone else. There will be a variety of price points given,, reflecting individual tastes. B/c right now both sides are making blanket statements about Class D. And both are wrong. But both are right. It’s the specifics guys. Cuz right now we are both just hitting our heads against the wall. In the words of a prior college professor, “it’s the specifics stupid”. |
guidocorona 1graber2 What I said was G, they can’t yet because the mainstream manufacturers (Motorola, Hitachi, Fairchild STMicroelectronics Texas Instruments ect ect) haven’t started manufacturing them yet for maybe $2 each, because GAN is invented and made by a small (relative to the above) development company (EPC-Co) , they on sell the licence to major manufacturers to make them. (EPC-Co) also invented the power Mosfet in the 60’s which the major manufacturers use under licence from them to make. Yes Technics has the GAN probably direct from EPC in limited supply, and you can bet they’re not $2 each, hence the $30k price tag on the SE-R1, anlong with limited tooling costs. I’ve always stated that the 1.5gHz switching frequency used in $30k Technics SE-R1 was a massive stepping stone in the right direction, instead of the 400-600mHz used today by others. Because at 1.5gHz the low order output filter can remove "almost" all the switching noise without any effects down to around 5khz into the audio band which happens with all other Class-D’s now. As Cyril Hammer of Soulution amps also says, we need to get even higher, he’s at 5gHz I’ve always thought 3gHz is fine, and when I see that on the way with future technology, it’s time for me to start advertising my boat anchors. Cheer George |
George, You are so yesterday.....he he. Check this link out.....no, they are not mosfets as Mouser has no category for them at present.....download the data sheet.....these are $5.50 each and anyone can buy them when they arrive in Nov. They also have higher current ones for $8 each due in Oct. https://www.mouser.com/ProductDetail/GaN-Systems/GS61004B-E01-MR?qs=sGAEpiMZZMvplms98TlKYzJ7xUKby2GKgG%2funvqgEAPyX8Mt10R2gA%3d%3d What so funny is that you only need a couple of these per channel to make multi-hundred watt amps. These are only slightly more expensive than the mosfets everyone is using now. The revolution is happening. Get rid of those heavy boat anchors before they are worthless! |
Class D Output filters are load dependent. From TI: The LC filter response also varies with speaker load impedance. The load impedance determines the damping ratio of the output LC filter and is classified as overdamped, critically damped, or underdamped. It is also important to understand the speaker load impedance variations for the application and select the L and C values that suit the expected load variations. Ideally, the LC filter value is selected for a critically damped, flat passband, and phase response. Two considerations when selecting components for the second-order low-pass filter is the cutoff frequency and Q factor or damping ratio. Like any other amplifier, Class D will interact with non-linear speaker impedances. There are multiple output filter topologies and each will interact differently with different loads. Stating that 1.5GHz will solve all the problems is as silly as saying a 10MHz Class AB bandwidth has to sound better than 100KHz. As far as GaN devices, there have been countless ’type’ as the new sliced bread for the entire history of electronics, be it tube, transformer, transistor, FET, IC, etc. ALL electronics involve a compromise and ALL electronics interact with their source and load. Specific recommendations border on risible. |
You might have a point George.... I just did a quick Google search and came up with this article.... https://phys.org/news/2018-07-path-high-performance-transistors.html If indeed Gallium Nitrite transistors may be applied to push into the Ghz switching frequencies for 5G transmitters, they will need to be eventually supplied by mainstream/major fabs... Perhaps we will see more high speed GaN transistors before long. BTW, I did not know that Soulution is already using GaN technology. G.
|
ricevs You need to read and comprehend better. Go back and read my post again. I never said they were, your going off half cocked again. What I said, the inventors of these new GAN devices (EPC. Group) YET TO BE TAKEN UP BY THE MAJOR MANUFACTURERS (just in-case you have bad eyes). Were also responsible for inventing the power Mosfet years ago. " Alex Lidow, Ph.D. CEO and Co-founder Alex joined International Rectifier (NYSE:IRF) as an R&D engineer and is the co-inventor of the HEXFET power MOSFET, a power transistor that displaced the bipolar transistor and launched modern power conversion." |
guidocorona3,975 posts09-04-2018 8:50amThank you for digging this up G, maybe now the doubters will "back off" It’s frustrating when posters like last one I had to address, skip read something get it all ****** up, before their mouths spew forth. BTW, I did not know that Soulution is already using GaN technology.That’s is interesting they have applied it to linear amplifiers, maybe used in their power supplies for full rail regulation? The only power amp I knew of that did that was the old Naim 250, nice sounding but didn't like Quad 57's, it oscillated and blew up, in the first second of turn on. Cheers George |
| Post removed |
ieales Not "all" but the major one, that point to listeners having issues with the upper/mids and highs. Cheers George |
@guidocorona Class D, as analog as it has been, was always the bastard design. Many, many thanks to Guido to lending his splendid ears to critic the prototypes Oganesson amps line from Merrill Audio and also his generosity with excellent suggestions which some of which have been implemented. There are a few items with Class D and switching frequency is not one of them. Although the GaN transistors allow for faster switching, it is really all the removal of dead time, overshoot, and ring that has resulted in the exquisite nature of the GaN amps. Switching at a higher frequency only introduces more problems then it solves. I have a thread introducing the ELEMENT 118 Power amplifiers on tour. Feel free to take your best Class A amp or any other amp to compare with the ELEMENT 118. Currently you can do that at distinctivestereo.com in New Jersey, or HearEverything.nl in Europe or audiogenese.fr in France. More sites to come in the US. As noted earlier, issues with prior Class D was deadtime, overshoot, ring, and to add to that the heavy use of feedback to reduce distortion. With the ELEMENT 118 Power Amplifiers and the Oganesson line of amps, the dead time is zero. (Trivia: Oganesson is the ELEMENT 118 in the periodic table). That means no dead time at all. This takes any argument away from Class D whatsoever. The rest is design - reducing overshoot and ring means designing the circuits and PCB to bring the parasitic inductance and capacitance to a point where it has no or very little influence on the board. Finally the last piece of magic in the ELEMENT 118 Power amplifiers is that it has zero feedback - it is an open loop design. This frees up the system much like an open baffle speaker system does to speakers. We are shipping in limited quantities so you can look for reviews coming. But why read about anything about Class D when you can hear it for yourself and compare it directly with your amps. This is an open invitation to anyone who can travel to NJ. I hope to have more sites soon. Hope that helps the Class D conversation. A bit more on GaN Transistors. They are fast, allow great switching, limited to a few vendors like TI etc. However put a Bugatti in the hands of a neophyte and you still cannot win any races. GaN Transistors in itself, while providing the technology to finally make Class D the best, still requires a whole lot of design challenges behind it. But yes, it is the future. |
Georgy, You misinterpreted what I said about mosfets.........The category that mouser put these new GAN devices in was under "mosfets" (they have no category for GAN devices yet)......this is why I said they were not mosfets......so in case you read their thing real fast, you might think they are mosfets. Which is why I suggested downloading the data sheet. So, the one going off half cocked is...... Also, I think Merrill has a great point......maybe we don’t need higher switching frequencies.....just less overshoot, dead time, ringing via circuits using super high speed output devices (GAN). The use of parallel output mosfets (like the older Icepower amps) makes it worse with even more capacitance. The ICEedge modules have one pair of output mosfets that give 1200 watts a channel into 4 ohms. Icepower also claims they have "continuous dead time compensation". Maybe these two things are part of what makes the new ICEedge modules so good. Surely, this is not zero dead time.........but I will say these modules implemented right are really sweet. |
Thank you so much Merrill! Indeed I had suggested a few small things... I believe that you actually implement my recommendation to use 20A IEC to maximize stability of connection with heavy power cords.... Well, at least now, if anyone complains about 20A inlets, you can refer their lamentations all to me *Grins!* And yes, the Element 118 prototypes I played with were already exceptional performers, even with their pre-production circuits and assemblage! BTW, have you published pricing for Element 116 and 114?
Saluti, G.
|
ricevsPlease point to where it says I think they are Mosfets?? I said the GAN device was invented by the same guys (directors of EPC) that invented the Power Mosfet!!! All those years ago. They (EPC) are into inventing/developing and selling their patented inventions to the major semiconductor manufactures, just like they did with the Power Mosfet. Also the ones used in the Techincs SE-R1 may not even be the same ones that are on Mouser that are non existent not in stock anyway. BTW "G" here is the difference in switching noise ringing on a square wave between Mosfet and GAN, https://www.technics.com/content/products/r1/images/se-r1-img2-2-uk.png there is still a little ringing but it’s far better than what all the other Class-D’s do. https://www.stereo.net.au/forums/uploads/monthly_2016_12/583f6e91157f6_Class-Dsquarewaveringing..jpg... And this is at 1.5gHz at 3gHz it could be all but gone, without effecting down to 5kHz into the audio band. |
Good grief, you still don’t get it. I never said that you thought they were Mosfets.....never. The link that I posted sent you to a page on the Mouser site where the GAN transistors are listed as Mosfets. I just wanted to make sure you read the data sheet to see that these are indeed GAN devices. If anyone looks fast at that page they "might" think they were Mosfets as Mouser mislabeled them as they have no category for GANs yet. You were the one that said GANs were only made by EPC and hard to get. My post was to show that GANs are made by others too, and that you can buy them soon at Mouser. End of story. Let us move on! |