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.
I still here the same fear obfuscation and doubt thrown at Class D amplifiers, without meaningful research behind it.
One of the biggest: Class D can't be as good as (blah blah) until the switching frequencies are above x Hz.
With zero objective evidence of such a thing. This is a vague, moving goal post. I've heard a number of Class D designs that equaled or better very expensive Class A designs.
I'm not asking you to like any particular class D design, nor am I saying all Class D amps are going to sound as good as any linear amp with particular speaker. I am suggesting this is thin techno-fear without research or experience behind it.
Yes, there is ultrasonic noise. So what? All amplifiers have noise. I have seen and heard zero evidence of this being audible. Yes, there will be amplifiers that will move the switching frequency from 450kHz to higher. So what? At what point, exactly, will it be high enough? What measurements, exactly, and what threshold of those measurements, will satisfy you that they have reached audio nirvana?
You do not have to like Class D. That's fine if you do not, but I've read encyclopedia's worth of hogwash on this particular subject here and elsewhere on the net. It's like a scam diet, which proclaims that x protein is the root of all evil. Buy my new book and I'll show you how to avoid and heal your gut... blah blah blah.
I also want to point out, I've been listening to Class D amplifiers since the 1980s. They were horrible, despite overall reasonably good specifications. So I'm not saying you should listen with specs, but rather, find the specs that correlate to audible effects. 400mV of 500kHz noise is measurable, but not audible, and my amps sound a lot better or as good as several Class A amps with all the speakers I've heard. I would gladly trade the size, cost and efficiency in exchange for a measurement that has zero bearing on my experience.
I'm using a PS Audio HCA 2 with the Cullen mods and I love it.
I auditioned a variety of amps in my home - a high powered ARC tube amp and a Pass Class A amp at the same time I had the PS Audio. I think I may have liked the Pass amp about as much as the PS Audio, but I'm inclined to keep my gear turned on all the time I didn't think I'd like the extra heat and energy usage.
Time and innovation march forward so I'm sure there are others that are better, but I'm not feeling any urge to upgrade at this point.
I haven't seen much discussion of the NAD M22 outside of general discussion of the Hypex nCore modules, but I've had this amp for the better part of a year. It replaced an Ayre V-5xe which put out too much heat for the hot southern summers I have to endure. While perhaps it doesn't have quite as much depth as the Ayre, it has incredible bass definition and control, a wide soundstage, and a sense of liquidity, propulsion and flow that the Ayre definitely didn't have. It has a pristine clarity and neutrality without seeming anywhere near harsh, dry or boring, and the dynamics are thunderous. I really couldn't ask more from an amp. Considering I see the M22 going for roughly 55% off the MSRP around these parts, I don't think there's a better performance bargain for power amps on the used market.
There isn't time to read all of this thread, so my apologies if it's already covered the Red Dragon S500, but I've had that for almost two years and am really pleased with it. Sound is detailed, balanced across the frequency range, bass is deep and articulated, mid-range is clear, treble is also clear and realistic though I sometimes think it might show a little more sparkle. Certainly it's well ahead of the Class AB monos I had previously, and they'd been well recommended.
The main partnering equipment is an Esoteric X05 SACD player, Townshend Allegri preamp, and B&W 804S speakers.
I don't doubt that there may be better Class D power amps. Some will be better because of their design and the quality of their components. It's also possible that some Class D modules are better than others. Living in Britain I don't get much opportunity to compare the sound of different systems. I did hear one of the first NORD NC500 power amps (it's only an hour's drive to where they are made), but the demo wasn't very successful from my point of view - mainly to do with the circumstances and not necessarily a criticism of the amp itself. Buying the Red Dragon was something of a risk because although I could return it within 45 days, I wouldn't get the import duty back and there's be expensive carriage costs. But it's been highly successful and I'd probably have to pay a lot more to get something that performs significantly better; though in five years' time, perhaps, when things have moved on a lot, better quality may be available more cheaply.
Nearly forgot about my second system. Linn Classik all in one which uses a 70wx2 class d amp and sounds pretty darn good for what it is and I have no desire to replace it with anything
I did try a pair of bel canto ref 500m monos a couple of years ago but for reasons I think mostly associated with the other gear I quickly moved on!
However in my ht rig the move to class d amp was a massive step forward in every way. Replaced my Emotiva amps with a tiny single nuforce power amp making a claimed 150w x8, only using 7 channels for my 7.1 system. The emotivas claimed 300w x2 and 250 x5, not quite sure where they were hiding those horses as the nuforce creamed them in every aspect. dynamics, action, dialogue, sheer volume were vastly increased with the nuforce. and now I have one tiny little box which has replaced two behemoth amps that were sucking juice and pumping heat.
I will at some stage give a pair of mono class d amps a whirl in my main rig again I am very sure!
Thanks MDE.. gives me something else to read about. His approach seems a little different and his units carry a bit of weight to them (Makes class A/B people like me feel more comfortable!). I'll PM you fo rthe other info!
@jdavis37 Not all Class D manufacturers use third-party amplifier modules. Check of Digital Amplifier Company. He designs his own Class D amps, or at least that's what he says (see website.) I own a pair on his Maraschinos and I love 'em. I also have some experience with other brands you mentioned. But I'd rather not speak of that here. PM me if you want more information. And I am not affiliated with, nor compensated by, Digital Amplifier Company...just wanted to get that said.
Heat and weight are not a concern for me, either. But I can see where those 2 things might be appealing for some. I won't lie in that I am struggling some to be really attracted to Class D for now. The technology seems to be changing rapidly whereas Class A/B at the least is mature. Same reason why in general I do not prefer paying for a DAC built in to the preamp unless the maker has a way for future upgrades. Dropping $5K or $11K for a pair of monoblock Class D amps only to see a much improved amp board emerge in 2 years would hurt my financial feelings. My spousal unit is very good with accepting my expensive hobbies to a point. Course if that $5K Class D amp already produces sound quality I find superior to every Class A/B amp I can find in the same price category then it may well work. But am giving consideration to some SST equipment (Son of Ampzilla 2 and Theobe II) as well which will not cost as much as some of the Class D options I am looking into! Course maybe I should just stay with my current setup... it is good and is now free :)
I do though see some advantages regarding heat generated (if that is a concern.. for me it isn’t) and size/weight. They offer a ton of power in a small mass versus trying to heft around a 90 pound Class A/B amp or an even heavier (with less power) tube amp.
I see my system as something I want to get the very best from, and if I have to compromise and pay for it in less efficiency so be it.
I wouldn’t buy a Ferrari put low octane fuel in it, stick cross-ply tires on it and drive it like a granny just so I could say I’m being kinder to the environment.
But Class-D amps with the promises of higher switching frequencies technology in the future, may become all they need for me to jump camp, then my current amps will become door stops or boat anchors.
I do though see some advantages regarding heat generated (if that is a concern.. for me it isn't) and size/weight. They offer a ton of power in a small mass versus trying to heft around a 90 pound Class A/B amp or an even heavier (with less power) tube amp.
Thx George.My only experiences are with Class A/B mostly and some Class A. I have heard tube amps but never owned one, and in past thought of Class D as mostly sub type amps (my ignorance). I started reading about the newer Class D amps and the price range is fairly broad. I also recognize pricing is not always linear with cost (whatever market will bring). But it is hard to see how 2 amps using the same identical amp board can vary in price so much which of course begs my question of why.
If the cost of the parts, including cases, connections, etc. as well as the actual amplifier modules is a lot cheaper than their Class A/B counterparts, and their sound quality is close but it results in an overall cost reduction for the buyer than I would be more encouraged. It is difficult for me to hear much of this stuff without buying it. Not many nearby sellers.
But I am probably missing something along the way. If the more expensive units are adding proprietary mods that would be one thing. Otherwise it starts sounding like a prettier case, etc. is adding a lot of cost!
So my question is with the main boards themselves being made by a third party, how does one go say from a $1400 D-Sonic amp to a $5000 Bel Canto (or other similar) amp (per pair) up to a Merrill Veritas at $11K plus (pair)? I realize a nicer chassis, etc.
In the "hiend" Class-D's there must be a huge profit margin compared to linear amps, even with the glitzy cases, as what's inside is worth peanuts compared to similar dollar linear amps.
Hi.. I have been a Class A or Class A/B amp owner my entire adult life and trying to get a firm grasp on Class D amps. I have read through several threads and like many subjects this one is similarly polarizing. I'm not biased either way. Just seeking information and if I decide to change amps, getting the sound I'll enjoy.
It seems there are about 3 major players in companies that actually manufacture the amp boards, and that most people selling Class D amps are buying the boards versus designing and building their own (probably some exceptions). If I am correct this is very unlike most Class A and A/B amp manufacturers.
While I have never truly understood the prices attached to esoteric items, I do understand basic marketing and getting for a product what the market will pay. This may or may not be attached to the cost to produce said item.
So my question is with the main boards themselves being made by a thrid party, how does one go say from a $1400 D-Sonic amp to a $5000 Bel Canto (or other similar) amp (per pair) up to a Merrill Veritas at $11K plus (pair)? I realize a nicer chassis, etc. will add cost, and same for internal wiring and external connectors but am trying to see what each make ris adding to their product to result in so many price variations when the main "guts" are so similar. Thx
erik_squiresOP3,082 posts01-29-2018 4:20amSorry George, as always, you are going to have to pivot from one point to another by yourself. If you need a dance partner it is not me.
Erik
That's a cop out Eric, your the one who said said: "
Most Class D amps I know of do considerably better. I'm more than a little surprised PS Audio put that out there."
I ask again, Eric.
Please show JUST ONE Class-D, with a clean 1khz sine wave, without using the Audio Precision's auxiliary AUX-0025 passive low-pass low power filter.
I have had a Nuprime class d amp for a few months now,and am very happy with it!The bass control is excellent!Im using it with a pair of 805 diamonds with great results!I tried it out with a pair of Thiel 3.7’s with great results also!I need a little more power for the Thiels I think?Im on the hunt for another class d amp for them.Im converted,class d rocks for sure!
Heard it again, still don’t like it. Wyrd4sound and.. Veritas amps, looked cool, sound was blah to me. I like class a, or ab, even a switching class h has more feeling to the music. Something about the d sound just don’t sit right with me.
It’s just.........like 1 dimensional, or no emotion to the music, a,ab,h just have a quality to them when I’m listening, I don’t get from d class sound.
shadorne6,590 posts01-28-2018 8:06amLittle known factoid.
AES17 brick wall filters allow Class D Amps to report specifications IGNORING all the switching noise above 20KHz!!!! And there is a LOT of noise....
Stereophile do similar now testing Class-D as not to upset readers with the noise on the graphs and to keep the manufacturers happy in case they may advertise.
They use a very low power handling Audio Precision's auxiliary AUX-0025 passive low-pass filter between the Class-D's speaker output and the test equipment, which eliminates noise above 200kHz.
On figure 3 you can see the switching noise of the 1khz test sine wave, it will be far greater if they showed with a 10khz sine wave.
That's not really a factoid so much as an operating principle.
You make it sound as if the specifications are illegitimate, they aren't. The filter removes the noise you are talking about, so that the noise is on the inside, but not the outside (mostly).
Sure, if you measure any random point inside the filter, you can find horrible looking signals with little resemblance to audio. True could be said of any DAC though. :)
Okay, 70W on the Zu Omen Defs is plenty of power; almost overkill. I don't think it's too much since it's such clean, low distortion power You're virtually guaranteed the amp will never clip and you'll have plenty of reserve power for transients. I think you're really going to like class D with your Zus and I'm certain there'll be much less heat in your room. Sorry for the belated response, I just saw your post. Have you got the amp yet? I'd like to hear your thoughts on the combo.
Noble, my speakers are the Zu Audio Omen Def. 100dB, very easy to drive - I am pairing them presently with a tubes SET pumping "only" 24W. That review that you mention is for the old monoblocks. The new model is 70W with standard PSU and 100 with the improved PSU. I ordered the best one. I'm expecting to get the amplifiers in 3 to 4 weeks. Then I can post a review.
I've never heard any of the Temple Audio amps so I'm unable to provide you with any useful feedback. I noticed the monos are rather low powered at 40 watts/ch (the review doesn't mention whether that's into 8 or 4 ohms). I believe you know how important it is to match an amplifier's power rating and sound characteristics to your speakers and therefore assume your speakers are very efficient. Please let us know your room dimensions and what speakers you'll be using so we can offer further guidance.
@migueca - let us know how you find them. I think you'll love them. I have some mystery monoblock class D amps that I love. Before that I had a Crown class D amp that was a great performer. But the switch to consumer monoblocks brought way more clarity, definition and power. I also have a Dayton audio class D I use for outside. It sounds great hooked up to good speakers, but these serious class D amps obviously trample all over it in terms of.. everything.
Erik and Noble, Thank you for your explanations. Yes I am going to try a class D amplifier from this new generation of modules. I've had an experience some years ago with a Tripath from Dayton Audio and I must say, although cheap and not a truly HiFi piece of gear I was impressed! Now I'm obviously expecting a much higher quality from the new breed of amplifiers.
I have been asking questions to many people from company owners/designers to dealers and forums members. And I'm getting solid and coherent answers that are helping me choosing the way to go. After evaluating many options I came down to three brands that are offering me what I'm looking for as a whole - price/performance/customer service. They are Class D Audio, Digital Amplifier Company and Temple Audio. They all seem to be fantastic choices, but I can only buy one and at this moment I'm closing a deal with Temple Audio - ordering the Monoblocks. Soon I'll be posting my review. Tank you for your sharing of knowledge!
I agree with Erik that the main benefits of mono-blocks, regardless of the amplifier type, are increased headroom and channel separation but with the former being more obvious than the latter.
Increased headroom in an amp is mainly evident in its ability to more accurately reproduce the large dynamic range of live music. My experience is that a system's ability to quickly and powerfully reproduce musical passages that progress from soft or moderate volumes to suddenly higher volumes significantly adds to the illusion that you're listening to live music in your listening room; amplifiers without large amounts of headroom and the ability to deliver it quickly typically will not be able to convincingly create this illusion. However, there are class D stereo units available that contain 2 power modules, with a devoted power supply for each, combined in a single chassis. Some of these dual-mono stereo amps even utilize separate power chords for each channel/module. I've never compared the performance of a dual-mono stereo amp to a pair of mono-block amps but I believe most people, including myself, would be hard pressed to distinguish between the two.
Technically, with mono-blocks having each channel contained in its own chassis and physically isolated from each other, it would be expected that their scientifically measured channel separation stats are superior to dual-mono stereo designs. Whether you'd actually hear this superiority is questionable.
I've used 2 different stereo class D amps in my system (a classD Audio SDS-440CS and an Emerald Physics EP-100.2 ) and currently use a pair of D-Sonic M-600-M mono-blocks. I would characterize them all as having very good channel separation with a solid and stable 3D sound-stage illusion. I haven't noticed an obvious improvement in channel separation with the mono-blocks but have definitely noticed an increase in headroom and a greater dynamic range with the mono-blocks in my system.
I know from your posts that you're thinking of trying out a good class D amp in your system and you're considering trying a Ghent or a ClassD Audio model. I highly recommend my first class D amp, the classD Audio SDS-440-CS. It's a true high quality bargain at only $630. It's powerful (220 watts @ 8 ohms/ 440 watts @ 4 ohms), has extremely low distortion levels, very good bass response, is very detailed and neutral in sound character with music emerging from a dead silent background. The mid-range and treble response is very smooth and never bright or harsh like a tube amp without the treble sounding rolled off at all. Here's a very accurate review from a professional reviewer:
They also give you a 30 day in-home trial period with a 'no questions asked free return policy' if you don't like it for any reason. Very low financial risk involved but I seriously doubt you'll want to return it.
I don't think the case makes as big of a difference as the power supplies.
Both ICEPower and Hypex allow you to use a single power supply for 2 channels.
This has potentially two benefits:
- Headroom - Channel separation
Lots of good stereo amps share a single power supply though, so having dual-mono power supplies is by no means an absolute requirement.
Spec-wise, the Hypex modules are better at very difficult loads, like electrostatic speakers. In practice with "normal" speakers, I can tell you I have the ICEPower in my living room and cannot hear a difference from a linear A/B amplifier. I have Hypex designed amps on my desktop system, via an NAD D 3020, but this is a bit of a unique design. All I can tell you is I'm very happy with both.
Two more questions regarding amplification modules: How different is the sound of a Hypex from the sound of an ICEpower? Do they have distinctive sonic differences? And how important (or not) is it to have a dual-mono (in a stereo single case) rather than a single amplification module to produce stereo?
I experimented with two Class D amps in my system; Merrill Audio's Taranis and Digital Amplifier Company's Maraschino Monoblocks. My system consists of an Esoteric X-03 SE CD/SACD player -> PS Audio DirectStream DAC -> amp -> Reference 3A DeCapo BE.
I chose Tommy O'Brien's Cherry Amp Maraschino monoblocks over the Merrill Audio Taranis. Nevertheless I found both amps to be detailed, powerful, and musical...albeit the Taranis more powerful at 400WPC. The Cherrys are small, efficient, and at 6"x6"x8" easy to move around; the Taranis is a single-chassis configuration. However the Taranis' single-chassis configuration did not figure into my decision-making.
Tommy encapsulates his Maraschino models in their own shielded enclosure, mounted atop a marble block for stability, and separate from their outboard power supply. I like that the amp is contained in its own housing. IMO it minimizes interference between the amp and power supply. Taranis probably does as well but w/ the Cherries, I can verify the separation.
Each Cherry amp was meticulously packed, w/ its accompanying ps, in separate boxes. DC cables (ps to amp) are included, as is a pair of RCA to Balanced adaptors...how thoughtful is that?
Neither the Taranis or the Cherry amps sounded their best out-of-the-box. However after 48hrs of continuous power with about 10hrs play-time in between, the rough-edges were gone. That's when I realized Class D was worthy of my serious consideration...ymmv.
Will these be the last amps I ever own? I don't know. I'm the unsettled-type who likes buying new gear periodically. For now, I'm happy with my purchase. If I could want for anything, it would be an increase in gain from 22db to at least 26. But I trust Tommy knows best. After all, he's likely forgotten more about amplifier design than I will ever know.
In closing, if you're considering evaluating a Class D amp, I think you'll be surprised. It ain't the undeveloped technology it may have once been. Pick one of the brands bandied about here, give 'em time to break-in and make up your own mind. PM me if you want to hear more about the Taranis.
Each of the upstream upgrades were a long range plan to try and stay with a class D amp. Finally about 3 weeks ago I tried the new PS Audio Stellar S300 amp. I just called them to inquire but when they offered a good price on the Rotel as trade in I took the hook.
I think they got one of the engineers from Classe' to do the ICEpower implementation.
I am completely satisfied with the improved sound (proly a slam dunk considering where I was). I have pretty much turned off my Velodyne Micro V. Enjoy the tone and increased realism and sound stage. Running a little warm but nothing like a class A/B Unit. Now I can turn my attention toward my TT or SACD player.
If you have an amp to trade in, the S300 can be a real value.
Erik, and all the contributors, After having read this thread from top to bottom - lots of good information - my question is: Did someone compare the amplifiers from Class D Audio to the ones from Ghent Audio? Because most likely I will order one from these two.
Erik, I too am a big fan. I have a PS Audio DirectStream DAC, but found it didn't sound so good decoding MQA (even when Tidal did the unfold), so I bought a Brooklyn for MQA. I hope they will have a booth or a dealer at the Capital Audiofest, plan to attend this year, hope to hear the new amp, if it's on display. Evan
Anyone had a chance to audition the Mytek Brooklyn Class D Amp?
It's been years since I've auditioned a class D amp, I can't remember which brand/model, I do remember it sounding harsh (to me), but from what I'm reading, class D amps have come a long way lately.
As I have written elsewhere, the ICEPower AS and ASP series is a very modern sounding amplifier. No extra warmth or juiciness, but not stark sounding either. To my ears it is the equal of the Parasound A21/A23 amplifiers, and very similar sounding. I cannot hear a difference on my speakers.
Quite and powerful sounding.
You should also try NuForce, which uses a very interesting hybrid approach.
Although I am the happy owner of a class A tube beast that weighs almost as much as me, I'm curious about class D amps. I'm not getting any younger and handling my amplifier by myself is becoming an impossible task. Not to mention the heat and the cost of maintenance. I've been looking at some class D amps from Ghent Audio, Temple Audio and Class D Audio. I'd like to buy something under or at around $1000. Ghent Audio uses the ICEPower and the other two are using the Tripath. What are the main differences? Does anyone compared any of these three brands? Opinions?
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