@larry5729
answers to your why question:
- heat
- efficiency
- weight
- cost
- heat
- heat
answers to your why question:
- heat
- efficiency
- weight
- cost
- heat
- heat
High end Class D amps?
Just an observation and a question. Are there 'high end' Class D amps out there that are just as good as Class A, A/B amps? I realize that's a sensitive question to some and I mean no disrespect---but whenever I see others' hifi systems on social media, all of the amps are A or A/B. There's always Pass, McIntosh, Moon, Luxman, Accuphase, etc. Where are the Class Ds? For folks out there that want more power for less efficient speakers and can't afford the uber expensive Class As, A/Bs, what is there to choose from that's close to those brands? Thanks
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In general, solid-state (ss) amps reproduce deep bass frequencies better than tube amps. A good indicator of an amp's bass reproducing ability is its Damping Factor, which basically measures its ability to control, or start and stop, the bass driver. The higher the number the better its control. Class D amps usually have much higher damping factors than the other amp types; class D amps can be rated in the low thousands, class A and AB are typically rated in the low hundreds and tube amps even lower.There really aren't any speakers that need more than 20:1 in a damping factor and some need considerably less. On top of that, traditional solid state amps actually have enough feedback at bass frequencies to do the job (whereas they usually don't at high frequencies, which is why they are often bright and harsh). I always thought pure class A amplification was most ideal. So why manufacture Class D amps?Class A is all about the output section- keeping its distortion as low as possible and its quite effective. But this says nothing about the input section and driver circuitry, and the output section is still going to make some distortion (just less than if the same circuit were class AB or B). Class D uses a different means (switching) to make power, and so does not make distortion in the same way. There are basically two means that the amp produces distortion- the first is how accurate the encoding scheme is. The second is caused by the fact that the output transistors take a finite period of time to switch on and off and so to prevent damage to them, a bit of waiting is done to allow one device to shut off before the other is turned on. Otherwise current can shoot through both devices, heating them up quickly towards failure. This waiting time is called 'dead time' and contributes to distortion. The distortion signature is different from traditional solid state and does not tend to be bright. Instead it tends to have more lower harmonics like tube amps, and not surprisingly can sound a lot like a tube amp, except when the amplifier is overloaded. Certainly the reduced amount of heat is an incentive- this is the main argument against both tube amplifiers and class A amps and especially class A tube amps :) |
I replaced Marantz MA-500 monoblocks with Nord Hypex NC500 monoblocks. The Hypex amps are awesome. The Marantz are terrific, and I was happy, but the Hypex took it to another level. Had friends come over and listen to both. Speakers are Philharmonic Audio Phil-3 with two SVS SB2000 subs, one for each channel, and preamp is Cambridge Audio A308cr and player is Rega Apollo. Outboard NAD M51 DAC. In my own experience can’t beat these new generation Class D amps. Dead silent and ample transient power. Now I am building myself ICEpower 1200As1 based monoblocks. Had a custom case made by Ghent Audio, who did a great job. More power can’t hurt. Considered the Benchmark AHB2, which had terrific reviews and specs. Almost bought them, but I suspected more power is better. The Benchmark noise floor is measured a bit lower, but we are in extremely low noise territory to begin with with these amps. Some links for anyone interested: Benchmark AHB2: https://www.audiosciencereview.com/forum/index.php?threads/review-and-measurements-of-benchmark-ahb2... Nord Hypex NC500: https://www.audiosciencereview.com/forum/index.php?threads/review-and-measurements-of-nord-one-nc500... Hypex NC2K: https://www.audiosciencereview.com/forum/index.php?threads/apollon-hypex-nc2k-monoblock-amplifier-re... ICEpower 1200AS2: https://www.audiosciencereview.com/forum/index.php?threads/apollon-as1200-review-and-teardown.9373/ Purifi 1ET400A: https://www.audiosciencereview.com/forum/index.php?threads/review-and-measurements-of-purifi-1et400a... Benchmark has been measured to have the lowest distortion/noise. However, we are looking at levels generally below .005% I, for one, am not going back. These amps are terribly efficient. I previously had Bryston amps that were simply great, but that was 20 years ago. PS - I have a separate HT system where I use a $400 Crown amp to drive subwoofers (18 inch Dayton), I built. Clearly, others have different experiences and views. I have a cousin with the exact same speakers (we purchased them together), but he swears by his Audio Research tube system and I tell him he is wasting his money, and if he wants a tube characteristic, the Schiit Freya+ is difficult to beat, though his AR reference preamplifier is simply terrific. Have fun! |
Ncore, Purify or Benchmark is where it's at. Hook one of these up to a high-quality preamp and you've just arrived at top-notch sound on a relatively bargain budget. I have a March Audio Ncore design with a Wyred-4-Sound preamp and couldn't be happier. The next step would only be a Stage 2 on the preamp or the Benchmark HPA4. Set your sights on better speakers after this. |
I find that class D amplifier module designers or companies of that nature are looking to ’commoditize’ audio amplifiers and place themselves at the top of that ’food chain’ that they are building. As the quality of class d rises, then more and more ears are going to find that they sound not best, but ’good enough’ when that happens, and it is happening..and you can see it in all the class d threads...when that happens, then the ’war’ for quality will be over, and then we will have two or three brands of amplifiers, for ’the great unwashed high end audio masses’. and those two or three companies will use ’box builders’ as fame and fortune aggrandizers, or ’beasts of burden’ for THEIR module producing fame, where the box builders are invariably pushed to being simple minded idiots, capable of nothing... who are just resellers of Coke or Pepsi. Like computer builders, who use branded cards power supplies and cases..and whatnot ..for making computers. Skilled? sort of. Barely. But, it will happen, as there is money on the table and some will step in and be that box builder and be that maker of fortunes ---for the given class d module maker. I know this is true as for most of the module makers, at least so far in my contacts..none of them will sell product to anyone who tries to modify or change their modules to make that box builder the preferred choice among box builders. These class d modules are NOT PERFECT. No matter what hype may come from what company for whatever claim maybe made about perfection. As they will come out with another module tomorrow... and that new one will suddenly be ’the perfect one’. Basically, they are iterating like they did before... and before... and before... and before... Yet each claim is a stinky claim of audio perfection, yet each one gets replaced.. They want to sell highly branded COKE or PEPSI to YOU and to have you ignore the lowly beast of burden... and concentrate on them, the module builder. So, I can improve their modules. Its easy. every single module I’ve seen from anyone has design flaws, design choices... that could be better and do a better job of serving the music... and and sound better than they do. I’ve got the talent and the understandings in place through about 40 years of work, to see many of those flaws, to know exactly where they lie, and what to do about them. I’ve done it before and folks have recognized that when the given class D modules I worked on where at shows, and people hard them and said it was the best class d they’ve ever heard. But, if I were to change that module... then you might notice... and then the next OEM box pusher might suffer in sales. As I’ve got the better module, as I’ve improved it. I have to tell them what I plan to do with the module. I have to.I have to say it clearly, and upfront . As I can’t afford to do al the intellectual work, and make the changes, begin selling the amps, and then have access pulled. In that scenario, I’d have all the work done..out there..and then that work stolen and used by others. and I receive nothing for all my years of study, effort, and work. Zero. So, this ’difference’ is bad for the module company, and for bad for their ’other’ clientele. I can see their point. If I were them, I’d probably see it the same way. And I am forbidden to buy from them for OEM use. For the sin of making the module better. They’ve built themselves a trap. Where the customer gets the short end of the stick, especially if the customer wants the best. It is all...basically...a steaming pile. A giant steaming pile. I can’t give you a better class D amplifier, as I’m locked out from doing so. How do you like them apples? |
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Wow. Class D haters. There are Class D amps that suck and SS amps that suck. It is in the implementation, to a point, without having to discuss which is the Holy Grail. I had PS Audio Hybrid tube / Class D M700's. Replaced them with a used Classe CA-2300 SS amp which was much better. (to me, all the reasons etc). Replaced the Classe SS amp with a pair of used Mola Mola Kaluga's. Class D with awesome implementation. Blew away the Classe SS amp. Now I have Audionet Max SS amps. Guess what? Superior to the Mola Mola's but at a cost. Just because there is a 'module' does not make all Class D amps equal. And there is much more than just measurements. Listen at a given price point and decide for yourself. Pros and Cons always. My Kaluga's are still looking beautiful in our family room, driving Salon 2's extremely well. And the Revel's are power hungry. It would take a big amp or big pair of amps for SS to beat them. I know; I have such a large pair in my basement and love them too! Happy Holidays! Ken |
I’ve heard a few Class D amps. I still prefer the sound of a good tube amp or a pure Class A SS. But the inexpensive Crown XLS1502 class D amp sounded excellent in a friends system on his Martin Logan Monolith speakers. So the cheap inexpensive Crown amp worked well in a very expensive system. I tried the D-Sonic 800 watt amp and thought it was a product I can easily recommend. But it did not sound better in my system than my pure Class A 200 watt Threshold mono blocks. |
Teo_Audio, This is not my experience. I have bought IcePower modules and sold amps using modified modules. I am now modding Purifi based amps. The only thing you lose when you modify is the warrantee from the manufacturer. Most audio companies don’t want to modify the modules.....instead rely on their own input stage or whatever to make themselves stand out from the crowd. The Mytek amps are modified Pascal modules. Most people reading this have no idea how complicated and infinite audio is. They have not played inside a component and therefore tend to talk in generalizations. They have no idea that all Purifi based amps will sound different from each other.....all IcePower amps will sound different and all Pascal, etc. etc. Every single thing you do changes the sound. There will be a review soon on the VTV Purifi stereo amp with the tube buffer. The reviewer will be swapping different discrete op amp in the discrete IV converter stage and describing the sound differences. This is just the tip of the iceberg. What I do to the Purifi module makes it sound way better. What I do to the power supplies, the input stages, the wiring, the jacks, the input circuitry, damping, fuses, etc. etc. all improves the sound. Measurements tell you little about the sound of an amp. Most things that make for a lower distortion SOUND cannot be measured. All metal film resistors have a sound.....yet, they all measure the same. All brands of solder have a SOUND......also not measureable.....all wires, jacks, foorters,,etc. etc..into infinity. |
AGD Productions. https://agdproduction.com/ More affordable models than their current offerings are on the distant horizon in more conventional chassis. |
Given my experience with my Rogue Sphinx v.2 driving .7 Magnepans, pairing a tube front end with their Hypex class D amps is a winning combination. The folks at PS Audio are taking the same route with their latest Stellar amps. I will allow that my little 15-watt Class A monoblocs sound sweet with high-efficiency speakers, but I won’t put up with the heat that a high-power Class A amp puts out if you need lots of juice to drive a lower-efficiency speaker. It seems to me it’s all about the total circuit and how complementary the different stages are. |
Class D Amp, the D means digital. It uses the digital way to emplify the signal, not sine wave anymore. It came out about 2 decades ago.I remember Janpanese brand Sharp had one. But it represents high efficiency but rough sound. These years, some high end product begans to show on the market. I read from a HiFi magazine, the Lindemann from Germany and Jeff Rowland had already revealed a very high level stereo class D amp early 2020, but very expensive. |
The D in class D has nothing to do with digital. This amplifier topology just happened to be the fourth (after A, B, and C) to be described and was assigned the letter D. It does so happen that class D switches the output transistors, but then so does class E. It would be nice if this thread focused more on what differentiates a great sounding class D amp from a mediocre one, instead of the unsubstantiated reasons why class D can't possibly be considered high end. My personal experience with class D is limited. I had a pair of Nord NC500 monoblocks for a little while. There was a lot to like about them - the were very detailed, quiet, and powerful, as well as being small, light and cool - but I just didn't feel the emotional connection to the music that I did with the big Krell amp they replaced or the Parasound JC5 that replaced them. However, I don't believe my experience with the amps is an inherit limitation of class D. I just don't think these particular amps were a good match for the system I had at the time. I think class D has a lot of potential and I'm very interested to understand what makes some class D amps sound better than others. |
The Starke AD4.320 isn't sold out, is it simply backordered until the end of December. https://shop.starkesound.com/products/starke-sound-ad4-amplifier Pricing is still $839 shipped. I hooked the AD4.320 up to my Moabs today and liked it better than the PS Audio S300s that are on that system. |
Listen to Ric! He knows what's up. I had Emerald Physics 100.2SE monos (with custom fuses), which I replaced with PS Audio M700 monos, which sounded quite good, but I couldn't resist that Ric introduced his EVS 1200 dual mono IcePower AS1200 module based amp with a 30 day guarantee. Twice the power for my ~ 20 x 35 x 12 room. Similar $$$$, but no comparison. Im still waiting on the Voyager GaN amp. What little I know is that it is mostly a ground up design. Lots of trial and errors. Im still looking forward to receiving it, but even less convinced that it can be that much better than my EVS1200. Time will tell hth |
+1 jaytor! |
Well implemented class D amp should have no sound. There are companies that place tubes, resistors, op amps and other filtering to achieve a "sound" by adding distortion. The most neutral and best measuring class D will have a SINAD at least in the 90’s. Still one of the best measuring amps I’ve seen is the Benchmark AHB2 which is AB. Mainly try to avoid crazy tweaks they only make the amps worse. |
"Class-D likes benign 4-6ohm loads with low - phase angles, and that’s what the Maggie’s are, but when the loads get tough, then big Linear Amps come out to play." I agree with George. Class D amps can sound really good with the right speakers as he describes, ones with relatively flat impedance curves. I have the Bel Canto Ref 600M mono amps and they really mated well with a pair of ATC SCM 19V2 monitors I had for several years. I am now running them with a pair of Spendor A7’s and they sound great with those as well, so there are at least two examples where Class D gets it done, and done well IMHO. And oh yeah, that Rogue Sphinx is also a Class D integrated amp winner. Two thumbs way up for that little jewel (I own one)! There's a reason they can't keep up with demand. |
I'll add a vote for the PS Steller S-300. I have been using one for several years. It needs a good power cord like the Anticables. It sounds fantastic in my application. FYI I also own a Pass XA-25 that's also great. They are both fantastic amps that just present music in a slightly different manner. Neither is fatiguing. I am surprised the Stellar is so great as I have been a class D sceptic for years. The class A input stage on the Stellar must be responsible. Anyway, there's a large difference in the price of these two amps. I could happily listen to music played by either. |
bluorion: " So now I have a Luxman 505UXii integrated with a pair of Dynaudio S40s as well as pair of Tekton Lore References. I alternate b/w the Dyns and the Lores depending on my mood and musical tastes. I love the Luxman but I at times I wish it had some more punch or something. I caught a video on YT recently that had a new Luxman connected to a Pass amp (I think)---I can't seem to find it now. Anyway, it got me thinking about higher output class Ds (like 200+ wpc) and wondered how that would go. I really appreciate everyone's input and suggestions." Hello bluorion, My opinion is that you already assembled a very good system, with a very nice class AB integrated Luxman 505UX ii and the choice of 2 very good pairs of efficient speakers that I would think are well matched and sufficiently powered by a high quality class AB 100 watts of power. From what I've read, Luxman amps are generally regarded as sounding well controlled, smooth, sweet but also detailed. Do you perceive your Luxman integrated as having these sonic traits? If so, and along with your comment about "wanting more punch or something", I'm thinking the combination of your amp and both of your high quality pairs of speakers may be too controlled, refined,smooth and polite for your preferences or tastes. Of course, only you can determine whether my impression is true or not. If this is the case however, I do believe combining the very good preamp section of your Luxman integrated amp with a high powered class D amp is likely to add more dynamic punch and impact to the overall sound of your system. I think this would be generally true utilizing either pair of you speakers but I can't be certain because I lack useful knowledge and experience with both. I'd suggest a very good and safe initial step would be to choose a high powered class D stereo or pair of monoblock amps, on a 30 day free in-home trial basis from a reputable online retailer, and give this possible solution an audition in your own room, system and with your own gear and music. I'd recommend you try a stereo or pair of mono amps from D-Sonic because I'm certain you'll be very pleased with their high quality performance. they offer 30 day free in-home trial periods with full no questions asked refunds, I know they're reputable, the owner, Dennis Deacon https://www.d-sonic.com/, is great to deal with and all their products are reasonably priced. I have no association with D-Sonic, btw, I'm just a very satisfied customer. I also wouldn't hesitate to use even substantially more power than 200 watts/ch with a D-Sonic class D amp or amps; the power is very clean with low distortion and noise, the amps automatically shut themselves down when any malfunction is detected and your speakers will function flawlessly well beyond their maximum power ratings as long as the power is clean. Speakers are damaged by high distortion and clipping, not by very high power. Best wishes, Tim |
Why would a Class-D amp care about phase angle? Many have higher impedance at high frequencies which could come into play but the phase angle of the speaker load would have no impact. |
+1 to Flatblackround on Wyred4Sound. I'm running the ST-500 into ATC SCM-12 Pro passive monitors; preamp is the Violectric V281. The sound is superb. A convenience asset: I contacted W4S to ask if I could situate the ST-500 on its side due to cramped space on desktop. He said, sure, go ahead--it puts out next to zero heat. He's correct. I've run it this way for a couple years and it couldn't be any better. |
There is only one so far that has taken Class-D and it’s operation to the technology edge, that "could" even better the best Class-A or A/B’s. Cherry Amps already switch up to 2Mhz which is faster than the Technics. 3x switching frequency does not mean 3x less noise. That's a factor of switching frequency AND filters. |
Thank you for the working link pinwa & @twoleftears ! I was able to order it. My class d crown xls 2002 did sound good and acquitted itself well into my Maggie 1.6s & Legacy Signature 3s (paralleled 4 ohm=2 ohm load) but I enjoy the richer sound of my class ab Soundstream DA-1 supposedly produced in collaboration with Krell (believable by how it performs). I'll be one happy camper if the Starke can bring the music as well as the DA-1. |
lowtubes: "So the cheap inexpensive Crown amp worked well in a very expensive system. I tried the D-Sonic 800 watt amp and thought it was a product I can easily recommend. But it did not sound better in my system than my pure Class A 200 watt Threshold mono blocks." Hello lowtubes, So, the D-Sonic 800 watt amp sounded good in your system but not as good as your pure class A 200 watt Threshold monoblocks. Well, that begs a few questions you can, hopefully, answer: 1. Was the D-Sonic 800 watt unit a stereo amp? 2. What are the approximate price differences between these amps? 3. What are the approximate size differences between these amps? 4. What are the approximate weight differences between these amps? 5. What are the approximate electrical consumption differences between these amps at idle and full power? 6. Which of the amps wastes the most electricity by converting it to heat and, therefore, operates at a higher average temperature? 7. Is the single advantage of marginally better sound from the Threshold amps worth the many disadvantages represented by the answers to the other questions listed above? Tim |
@noble100 "From what I've read, Luxman amps are generally regarded as sounding well controlled, smooth, sweet but also detailed. Do you perceive your Luxman integrated as having these sonic traits? If so, and along with your comment about "wanting more punch or something", I'm thinking the combination of your amp and both of your high quality pairs of speakers may be too controlled, refined,smooth and polite for your preferences or tastes." Tim---you nailed it! I think that's what I'm missing---don't get me wrong, I love the sound from my 505 but I often wonder if the extra "punch" and bass could be added with a class D. From what I've seen on here, the class Ds could add some extra bass due to the higher damping factor. I may try the D-Sonic 800 amp and see what happens. Thanks for the recommendation. Question: if I connect the D-Sonic to the Luxman, will I lose the gorgeous blue VU meters? :) Thx |
"curious to hear your characterization of the sound quality difference between the pass and stellar pls advise your speakers and source" My source is either Qobuz through a Schitt Gungir Dac or from my turntable. I've recently spent a lot of time getting the turntable and arm correct. Tonearm is a Dynavector DV 505 with a Denon 103 R moving coil cartridge. The tone arm has been rewired with Anticables level 6.2 interconnects. (I ditched the DIN connector and wire which made a very audible difference.) All interconnects are Anticables level 6.2 single ended or balanced using the same wire. Line stage preamp is a PS Stellar Gain Cell. The S-300 is connected via balanced Anticable interconnects. All power cords by Anticable. (You could say I'm an Anticables fan.) The speakers are Fuselier 2.5, subwoofer is a REL T-5 i connected to the speaker terminals of the power amp via Speakon cable. Before using the S-300 I used a Manley Stereo 120 or a Threshold 400A. The Pass XA-25 is in a different small system driving Kef LS 50's and a REL T-5i. I like both amplifiers and did not expect to like the Stellar as much as I do. It very clean, quiet, and uncolored without being cold or "etched sounding" like I'd always thought of Class D amps. The Pass is a little warmer sounding and better. But heck it's almost 3 times the price. I have owned a lot of amps over my years in this hobby and found the class of the amp is not always an indicator of how it's going to sound. A lot has to do with how the designer voices it. As always your mileage may vary.. Good luck listening, |
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bluorion: " Tim---you nailed it! I think that’s what I’m missing---don’t get me wrong, I love the sound from my 505 but I often wonder if the extra "punch" and bass could be added with a class D. From what I’ve seen on here, the class Ds could add some extra bass due to the higher damping factor. I may try the D-Sonic 800 amp and see what happens. Thanks for the recommendation. Question: if I connect the D-Sonic to the Luxman, will I lose the gorgeous blue VU meters? :)" Hello bluorion, I agree, since we know your Luxman integrated has a very good preamp section, no guarantee but why not give a good quality class D amp or amps a try? However, I believe you won’t lose the blue meters but I doubt they’ll be active when using the pre-outs. Sorry. But there is an alternative solution for incorporating more punch, impact and dynamic range into your system you may want to consider, at least for the bass frequencies, is to add at least a pair of good quality subs to your system if you have the room. Your S40s only have a rated bass extension down to 41 Hz and your Lore References only down to 37 Hz, so you’re not hearing or feeling all the bass on your source recordings that typically contain bass down to the audible limit of 20 Hz. That’s a lot of bass and bass impact to give up. My main speakers, a pair of Magnepan 3.7i, only have a rated bass extension down to 35 Hz, so my system was also initially lacking the impact created by full bass extension down to 20 Hz along with powerful bass dynamics. I was able to incorporate this missing bass and bass dynamics seamlessly into my system, however, by installing an Audio Kinesis 4-sub Swarm distributed bass array (DBA) system into my room that worked incredibly well. Now, I’d need to know more about your room dimensions and budget, but this $3,200 complete kit system may just be the ideal solution for your system, too. Here’s a link of an Absolute Sound review of it that provides a very accurate description of what to expect it to provide: https://www.theabsolutesound.com/articles/audiokinesis-swarm-subwoofer-system/ Here’s a link to the Audio Kinesis website: http://www.audiokinesis.com/the-swarm-subwoofer-system-1.html I have no affiliation or association with Audio Kinesis, I’m just a big fan of the company and the 4-sub DBA concept because it works so well. I bought and installed this system in my room about 6 years ago and I honestly consider it the best upgrade I’ve ever made to my combination 2-ch music and 5.1-ch home theater system. I think you’ll probably think so, too, though even using a less expensive solution of a pair of good quality subs could produce similar results. But I’ll wait until you post a reply before continuing our discussion. Later, Tim |
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@noble100 Good points regarding the sub--that's a possibility as well. I've seen some good reviews about the REL subs. My budget is around $2k so the D-Sonic would be fine if I decide to do that. I didn't realize there were subwoofer 'sets' like the Swarm. Very interesting indeed. I've learned so much from being in these forums. I had a sub and satellites (from Canton) years ago and they were quite nice. I sold them many years ago and never owned another sub since. Definitely something to consider. |