That's not a valid argument. With a new technology, why would established manufacturers be better at implementation than those who helped develop the technology?
Class D is just Dandy!
I thought it was time we had a pro- Class D thread. There's plenty of threads about comparisons, or detractors of Class D.
That's fine, you don't have to like Class D amps, and if you don't please go participate on one of those threads.
For those of us who are very happy and excited about having musical, capable amps that we can afford to keep on 24/7 and don't require large spaces to put them in, this thread is for you.
Please share your experiences with class D amps!
That's fine, you don't have to like Class D amps, and if you don't please go participate on one of those threads.
For those of us who are very happy and excited about having musical, capable amps that we can afford to keep on 24/7 and don't require large spaces to put them in, this thread is for you.
Please share your experiences with class D amps!
861 responses Add your response
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I love the use of a page of 10 year old quotes about a developing technology. Beyond that, the article may only prove that all those famous designers didn't succeed in producing a good Class D amp. Only shows that they couldn't do it - not that it can't be done. As Bruno points out, it's a different engineering knowledge and skill set that many audio designers don't have. Kenny. |
George, Nice try I've read it all many times before. What are we going to do with you? Bruno never calls his modules digital,class "D" was just the next letter in the alphabet that hadn't been used yet. I know that tomorrow I will get too listen for 6hrs of wonderful non fatiguing class d amplified music. Kenny. |
So, to those confused by Class D vs. Digital, to be "digital" you have to convert or have the signal as an integer to describe the waveform. Like the digits in a CD track. This is "digitization" or converting an analog signal into a series of digits. Class D does NOT do this conversion, but the amplifier IS switched on and off. :) It’s confusing because what happens is that the comparator keeps the switch ON or OFF more or less in proportion to the incoming signal. This is why feedback is so important and completely different in a Class D amp vs. linear. The feedback IS essentially the only way the amp has to control the output signal, however this feedback takes different shapes. The more global the feedback, the more accurate the output. It’s a subtle but important distinction. Here is a list of Bruno's papers, I encourage you to read them, as I am sure I made mistakes, and the guy is one of the celebrated Class D amp designers of our time. https://www.diyclassd.com/p/application-notes-white-papers/ Best, E |
@georgehifi Interesting article, full of inaccuracies. One I may have helped propagate. Class D vs. Digital Amplification The article claims, erroneously, that Class D amps all have an A/D converter at the front. They do not. It is actually more of an Analog to Analog converter with a switching voltage amplifier in the middle. :) Somewhere there is an article or paper by Bruno Putzeyes chafing at the use of "Digital" to describe his amps, which I can't find right now. Worth a read if you can find it Class D amps (ICEPower/Hypex) generally rely on feedback to control the switching, which uses a linear comparator. There's no A/D conversion in the chain, it's not needed. Here is a good short article on the subject: https://en.wikipedia.org/wiki/Class-D_amplifier Interestingly, George, the Technics Class-D amp you are looking forward to IS more of a digital amp than most Class D in that it DOES have an A/D front end, followed by a DSP engine to do the calibration and frequency/phase adjustments to the original signal before feeding the amplifier section. You are really trusting the amplifier with a great deal, because it will chew the signal up and digest it before spitting it out again. This is an approach not entirely unlike Theta and Meridian have undertaken. Best, E |
Just a few of the industry's heavy hitters of hi-end design give their opinion on the merits of Class-D in a round table discussion with Absolute Sounds. http://www.stereo.net.au/forums/topic/110007-switching-noise-in-class-d-amps/?do=findComment&com... Cheers George |
Wait, didn't we have a manufacturer participate in this thread? I tried going to their web site but it seems down? http://www.iceh2oaudio.com/index_htm.html |
Ha! Thanks for the vote of confidence, Erik. Kdude - I'm only jealous that people get to hear all these amazing pieces of equipment. I'm curious, more than anything. But when I choose a piece of gear, I tend to stick with it for years. I am a content human. Messing around with my system is fun, but I certainly do not have upgrade-itis. Thank Buddha! The Ghents replaced a crown xls 1500, which replaced a NAD integrated. Can't remember which one, unfortunately. I'll look next time I'm at its current home. Any amp after these will probably be some kind of class d kit.. |
Todd, I'm glad you love what you have,Ghent audio makes nice cases I have them on my Nc400's.and I have heard they make a good Amp as well for the money. It's all about the music and if you get enjoyment with the gear you own and fits your budget I would'nt worry about it. Can you tell us what amps that the Ghent's replaced. All the best to you and enjoy, Kenny. |
@guidocorona, I believe Bel Canto's REF600M is based on Hypex’s NC500 OEM module and SMPS1200 power supply. They do not use the NC1200 Hypex module. I am hoping to try the 600's in next couple of weeks. It would be interesting to see how these mono's stack against the ATI's 544NC which is using the same NC500 module in bridge mode per channel. |
@guidocorona is correct about the module used in the Prometheus. http://www.stereophile.com/content/theta-digital-prometheus-monoblock-power-amplifier#1uPJbsjlSAtFgo... I wasn't paying attention to the specific module, just that it was a Hypex nCore. But they DO use the NC1200. All ff the nCore modules are easy to use, by the way, but you are correct, only the nc400 is available at retail volumes. Best, E |
One idea I had long ago was to build digital amp modules for the old Theta Dreadnaught line. Theta has already introduced a D version of the Dreadnaught though, here: http://thetadigital.com/dreadnaught_d_amplifier_info.shtml# Best, E |
NCore NC400 is a very simple to use module designed by Putseys for Do It Yourself implementations. As far as I know, the Theta Prometheus module is a full NCore NC1200 module, not a low end NC400. Hypex NC1200 cannot be purchased by individual audio enthusiasts for DIY projects. It can be sourced only by qualified high end audio manufacturers, such as Theta, Merrill Audio, Bel Canto, Rowland, and other similar companies. G. |
I've heard it said (by a class D proponent) that ICE sucks, but Iceedge is going to be a game-changer. Truth? Also, it's widely claimed that class D is improved with linear power supplies -- fact or fiction? Extremely uneducated and immature statements from somebody that has no real experience with class d for any substantial amount of time and really doesn't belong on this thread and should stay on his trash thread unless have something positive to contribute. My hats off too Erik for starting this thread probably knowing well that we that like class d would have to put up with this crap. Look which tread has the most interest of the 2,It's this one. Thank You,Erik. Kenny. |
Thanks @wtf I appreciate it, I had not noticed who that thread starter was, but I could tell the attitude was that of a brawler. Re: ICEedge There are probably already products out there with this technology we just don't know about them yet. From B&O's point of view I think the main focus is on custom power and integration into receivers, all-in-ones, etc. not really us uber-audio-geeks who want to be seduced with stories of custom capacitors with dielectrics made from the excretion of a rare Himalayan beetle. :) Honestly doing digital right is not easy, which is why Pascal, Hypex and B&O have been so successful. I think that in the high end, manufacturers are going to have to get VERY lucky to find talent who can bring on enough experience and insight to complement it. This is all pre-game BS though. :) Can't wait to see what the future holds. Best, E |
Hello all, Each individual component of a class d amp,the pwr supply,the input module or board,and Offcourse the class d module brand,work together in a synergistic way in the end result. It's all up to the amp designer and the implementation of mentioned components,all 3 amps that I own are slightly different. If you look at the other classes of solid state amps,the above mentioned matters to their design as well. Class d amps have come a long way and will continue to improve as time goes by,which is true with any newer technology. Kenny. |
@madavid0 From a historical point of view, your statement has value. In olden days, let us say about 10 years ago, ICEpower modules taken by temselves produced the kind of sound, which were not particularly musical. There were in those days several examples of ultra-basic implementation of ICE that did not sound particularly attractive. THe same modules, however, used by amp designers with a modicum of amp design knowledged yielded extremely musical amplifiers.... I already mentioned the Bel Canto REF1000 Mk.2 and the Rowland M312 as examples. It is my understanding that more recent versions of ICEpower modules do not share the problems of the olde ones. I did not know about ICEEDGE.... I'll try to find out about it. Your statement about ICEpower benefitting from linear power supplies is, a little tunnel-visioned... In the following sense. ICEpower modules, as much as class D modules from other makers, often integrated their own power supplies, or have companion ready-to-go SMPS for those amp implementors who want to create simpler amps at a lower cost. Most of these modules however, can be powered by power supplies of other origins, they be linear, toroidal, SMPS, or perhaps other types. Invariably, some of these supplies are very good, and some might not be. A good designer with knowledge of power supply design is able to enhance his class D amplifier with a custom supply..... I believe that Henry Ho has long term experience using linear supplies, with all reports pointing to great results... Rowland has been using custom SMPS for the last 15 years at least with equally great results. In the end, the type of power supply does not matter, provided it is sinergistic with the module, and truly enhances the musical experience. Regards, G. |
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Erik .. madavid0 is only here to provoke. Keep in mind he started this thread: https://forum.audiogon.com/discussions/class-d-trash |
ICEPower went through several incarnations. I can attest that the AS (or ASP if powered) is superb. ICEedge is the chipset without the amplifier. :) Just the brains. So I think that we’ll start to see a lot more product differentiation among vendors. The normal ICEPower module is 100% complete and tight in space. There’s no place to modify anything. At best, you can put in your own input buffer stage, and you can do lots with that. Transformers, tubes ets. but the ICEedge is the place where you can go really bonkers with part selection and circuit design. I have no personal experience with these amps and linear supplies. Best, E |
madavid I use bare ICEPower 250 ASP modules. They beat a lot of premier class A amps. Also, you bring a lot of attitude. Not everyone on this list has mentioned uber pricey class D amps. Some were quite affordable. If you are looking for a place to start a linear vs. class D argument I really would be happier if you took it elsewhere or started your own thread. As posted, this thread, which is one of the most popular on right now thanks to the readership as well as proponents who are participating is for people who like Class D. :) Thanks, E |
madavid0, the only time that I do not hear mesmerizing music with resolution, staging, imaging, macro and micro dynamics, authority, and amazing listenability with zero fatigue is when my class D Rowland M925 mono amps and the rest of my system are... Turned off. On the other hand, I believe you have heard these very same type of comments from me and many other music lover on this and other similar audio watering holes before.... And they ain't changing. This does not imply that my amps, being class D are inherently superior to yoursma.... Just that I love the kind of emotional music that my amps express to me, for my musical taste, with my other components, in my own home, potentially 24/7/52. Can my musical experience be enhanced further... Sure thing. Next Thursday I will be taking delivery of a Rowland PSU (Power Storage Unit)... An external power supply based on supercapacitor technology that I will apply to my Rowland Aeris DAC. I am excited about third party reports about it this far, and am anxious to try it on my own system.... But, my class D M925 mono amps are not going anywhere *Grins!* G. |
@autre The Wyred 4 Sound STi v.2 integrateds were on my list. They do not have a dac. The Wyred gear is very well reviewed and there are many happy users out there. http://https//www.wyred4sound.com/products/integrated-amps/sti-v2-series Cheers, Scott |
Thanks for the NuPrime recommendation. I'll check it out. That's funny Erik, I hadn't noticed people were mud-spelling it! It helps to have two other acquaintances with the same spelling as you. I eont take take this wonderful thread too far off track but I had two follow up questions. 1) anyone know of some good "standardly" equipped integrateds (no onboard dac)? And 2) as was mentioned in an early post, I had encountered RF issues with one of the amps. Curiously it was only through the line inputs, and while connected to the CD unit. This only occurred with one of the amps and not the other even though all the other pieces including wires were kept the same. Any ideas? |
@autre NuPrime IDA-16; I really enjoy mine. It has 200 watts; build quality and functionality is excellent and it sounds great. http://http//www.nuprimeaudio.com/index.php/products/amplifiers-and-preamps/integrated-amps/ida-16.html Cheers, Scott |
Erik, as many others have said, thanks for starting this thread. I've found it extremely informative and quite entertaining. I'm new to the Class D amplifiers but love them because of their sound and ability to run cool which is perfect for the tight fitting cabinet that I have. By pure chance thetwo integrated amps I've home auditioned were Class D: the Rogue Sphinx and the Peachtree Nova 125 SE. I was interchanging the two in my system which includes Kef ls50s and an old Onix XVD-88 CD player. The sound from both was phenomenal, but different from each other. Instrument representation seemed very accurate and vocals were gorgeous. Of course my descriptions should be taken with a grain of salt since I'm not an audiophile by any means. Both amps in my room sounded great but each portrayed music with their own distinct signatures that definitely made me curious to try some others. Given this does anyone have suggestions for a nice Class D integrated that they like? Price range would be in the neighborhood of the Rogue and Peachtree ~$1500. |
It's also important to say, differences are not better or worse necessarily. Maybe two amps sound different. Is one better or worse, is it worth caring about? Are you trying to make your ears more sensitive or enjoy music and movies more? :) We get all confused in our goals (Me too!) so it's important to be clear. Audiophiles too often think the next different thing is "better" when it's not. I think even John Coltrane was guilty of this, and would make endless takes until someone told him "You can't play it any better, just different." Best, E |
@jrunr I would listen to them. :) Bridging is a tricky thing, possibly involving slightly more circuitry at the front end, and possibly lower damping factor (Higher impedance). How much is audible? Is a higher 8 ohm power rating going to help you drive speakers better? (unlikely) The real question for me would be whether you need 500 Watts / Channel. :) The basic 200W/ch models are overkill for almost everyone. In a modest configuration (< 8 channels) you could have a lot of reserve power. Depending on the costs involved, you might also want to play with the 400 W/Ch nCore kits available from Hypex. I’m not sure how they compare to the ATI multi-channel amps. Best, E |