Class D is just Dandy!
A21 driving Focal Profile floor standers
I can’t answer that because I don’t believe in the class itself making a sound. If you ask how did it change between my A21 and ICEPower 250ASP I can honestly say they sounded identical in good and bad ways. Very laid back and maybe even too laid back with no euphonic colorations
I didn’t. I went to a Luxman because it sounded better. In particular, compared to both the Parasound and ICEpower it had more extension in the bass and treble and an almost tube quality to the midrange and treble. The Luxman just happens to be A/B. I suspect much of the sound quality of the Luxman however is in the preamp design so I hope to switch to a Luxman preamp (perhaps tubed) when I go active.
Making speakers is how I enjoy my hobby and the next step in my system’s evolution is to convert my 2-way speakers with passive crossovers to 3-way actives.
I can’t speak about that particular jump. I’m using a Hypex plate amp for my center and I like it a great deal, but the NAD hybrid amps are significantly different in design so hard to compare. |
I just realized this thread was started in April of 2017!! It has outlasted GeorgeHifi as well as MQA and still going strong. Thanks to everyone who has made a constructive contribution to this thread! FYI, I've gone from linear (Parasound) to Class D (ICEpower) to LInear (Luxman) and am about to transition fully to Class-D active speakers based on Hypex amps and DSP. |
@phusis You make a good argument not to judge amps by their class alone and to be honest to yourself about what you personally like to listen to. It’s your money, not mine, so you should be happy with your spend. I can explain my likes/dislikes without needing others to feel the same way. |
@smargo - I hate to make broad judgements of amp classes, but you bring up an interesting point. There are mega buck class A amps I simply do not like the sound of. I have often wondered if they are an acquired taste, like beer with a strong hops flavoring, while to me most Class D and even A/B amps sounding better than some Class A for my money. Also wonder now if Class D will be an acquired taste for the new generation of audiophiles, who will reject A and even A/B as not sounding as good as D. Kind of how we might prefer mom/dad's cooking to a fancy restaurant. |
@mbrusso What kind of speakers do you normally listen with? |
The operating principle of a class D amplifier is that it uses a filter to eliminate the switching waveform from the output. In this manner Class D shares the function of the filter used at the output of the Berning amplifiers. In either case, this is part of the operating principle and can’t be separated out; the idea that anyone would run one without the filter is ludicrous. |
Hey @georgehifi Remember this: 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. I'm curious why you'd want to participate in this thread, with exactly the same 3 arguments you've made before. Over and over again, especially since it seems to most readers you keep attempting to hijack it. Is there a new argument? Is there some reason why you don't actually go start a Class D bashing thread and leave this one for those of us who like Class D? Also, you have been debunked 50 ways from sundown. Over. And over. And Over. By everyone. Best, E |
As a young electronic technician, and PCB designer, I was entranced at the idea of ultra-wide bandwidth electronics. We often made gear for theaters that was flat to 100kHz. Very transparent sounding stuff. Tandberg was one of the brands I remember sounding great at the time, with astonishing slew rates. However, in modern times, I can’t say it has been the slew rate or bandwidth that has won me over at all. Spectral is one such amp, which I heard, and it was OK, but no, it didn’t stop me from buying anything else. That is, if the ultra-wide bandwidth had benefits, it didn't win me over to it. |
George, It seems no matter how factual I am you complain about me being abusive to you. You have made dozens of posting on this thread, and ignored the request in the OP and myself and others to start an anti-Class D thread if you are so inclined. You've also made the same arguments dozens of times. Would you please be a gentleman and go start your own Class D bashing thread? Thank you, Erik |
I'm afraid I haven't had time to go out and listen to a lot since the last show here in ... Long Beach? Newport Beach? I've also gotten to a poin where I'm very happy with the sound quality at home but not the remotes. :) Seems bad for me to find a dealer to listen to gear I'm not going to buy. Maybe I should ask manufacturers to send me gear to review instead?? |
but replace my simple little single ended tube amp? First, @wolf_garcia , I applaud you for being willing to expose your audio quirks without fear. I wish I had that kind of personal courage. ;-) But that’s just it. If you love the LP sound, only the LP sound will be good enough. If you have a particular niche of amp, no other amp will sound as good. It’s not proof Class D is behind the best solid state amps. If you have a love for 30 watt Class A, same thing. It's a bit like comparing all restaurants to mom or dad's home cooking. Kind of unfair to rate them that way, unless of course your mom (or dad) was an absolutely terrible cook. As I always say, buy and enjoy what you like, even if it’s’ some quirky SET or full-range with a giganormous bass horn. That’s fine. But I think it’s unfair to diss Class D because it doesn’t sound like a SET. Among large solid state amps, I don’t know anyone who can listen and say "Oh, that’s a Class D amp, I can tell because....." Best, E |
Whether a designer takes advantage of this fact is another matter but generally speaking GaNFET amps should sound better as they have less distortion on that account. @atmasphere As you are well aware, I’m kind of touching on an issue of specmanship that that affects us with all amps. Can we hear "better" when you go from 0.01% distortion to 0.001%? I know distortion can be reduced, which technically means more fidelity to the input signal. What I don’t know is that this alone is audibility, let alone desirable. Like Tube amps, or Pass (who makes it clear this is his goal) the distortion profile may have more to do with euphonic capability than merely lower distortion. |
Personally, I think it's a horrible thing to price out a product based on component costs. I think everyone would be horrified if we did this consistently across audio. There's more to a high frequency design than the cost of the transistors. PCB layout must be done meticulously, and test failures common, so R&D matters. Still, having said that, Class-D amplifiers are quite good already. Better than some Class A amps, worse than some Class A/B. If there are actually audible benefits to GaN based amplifiers I look forward to hearing them. |
@maplegrovemusic I don't find good digital amps bright or fatiguing today. In the late 1980's I was listening to some digital amps that sure were though! I don't know how old the B&O/ICEpower designs are, but that's what I listen to every day now. :) It's quite possible the speakers, designed as integrated wholes, eliminated issues with the rest of the Class D crop. I will say that the Class D amps I was listening to wwas through entirely different speakers, TAD pro studio monitors from the time, so that could have been a horrible match overall. |
No matter how nicely you ask George to start his own nay-sayer’s thread, he’s always going to share his impressive collection of articles about how planes can’t fly. No sir, they are too heavy and completely unreliable. Plus, you will fall off the edge of the world if you go too far. God help those of us who want to talk about how much we like Class D, because there is George telling us we are wrong. George would skip his own chemotherapy treatment to come and tell us this. |
Tom - Yeah, I’m using an NAD D 3020 in the bedroom. It’s a hybrid Class D designed by Hypex, so it runs a little warmer than you’d expect. It’s really quite nice. One thing I’ve learned recently is NAD is using 3 different types of Class D: 1 - Direct Digital 2 - Hypex Ncore 3 - The Hybrid approach they used in the 3020. It would be interesting to compare them side by side! I will say that while I am a fan of Class D in general, I’ve never heard a PWM amplifier I actually liked the sound of. I suspect they get the feedback (if any) quite right and can’t solve the output filter issues well. Erik |
New opportunities for those with a little DIY skill! Parts Express is now selling ICEpower modules new, and cheap! https://www.parts-express.com/cat/audio-amplifier-boards-modules/3464?N=21147+4294967118+4294960619&... You can put them together with cases from Ghent Audio for your own mono or stereo amplifiers! https://www.ghentaudio.com/kit/asp-mxr.html Enjoy! Erik |
Exactly like the A21 and A23, the the JC1 is high-bias Class A/AB. (model names in sentence above are links) Good amplifiers. Have not heard the JC1, just the A23 and A21. I have to agree, "class warfare" in this context is meaningless and with little to no supportable evidence. This is what showrooms are for though. Buy what you like listening to, which needs no justification. Best, Erik |
I just wanted to say I have been pure Class D for about 3 years and I have never, not once thought to myself "I'm listening to a switching amplifier." Now, are there things I want differently? Sometimes. Can I attribute that to Class D. Nope, not at all. Before this I was using a pair of Parasound linear amps to power my main speakers. I've never looked back nor gone "wow, I can really hear the slow switching speed distortion." Now, if I had tons of cash and space, I'd probably have a pair of CJ Premiere 8s (mono right?). Wow, what amazing amps. But that's because they are just amazing amps, not because I need to get off Class D. Best, E |
The esteemed Mr. Pass has done so much for the DIY and audiophile community that I absolutely loathe to criticize him or his works in an open forum, especially since he is not the one participating, george is. Instead, I will only say that you should spend money to satisfy yourself, not anyone else, including me. Listen for yourself. Buy what pleases you for whatever reasons they may be. I go to bed tonight able to rest because I know every 4th or 5th message in this thread @georgehifi will be raining on our parade, like warm spring showers on a cloudless day. Best, Erik |
This is all great discussion but doesn’t it come down to your ears, budget and preference for the love of music. Budget and listening preference will ultimately be the deciding factor. Yes, oh my Goddess, it’s like we are twins... If person A has a budget of 50 - 60k he’s not looking at Class D period in of story. Oh, wait, what????? I disagree. Just because I have x amount of dollars doesn’t mean I’m going to spend it. My goal is not to spend $x, it’s to spend as little of $x as I can and be happy with it. If I’m happy with $x/10 then that’s all I will spend. To do this however you have to give up the notion that price is any sort of arbiter of performance. I no longer believe this is the case. If you feel that the market value expresses your desire, then make yourself happy. :) Best, E |
@cleeds I’m perfectly OK with you not liking a class of products. That’s not what I’m talking about. It is the notion that Class D switching speeds are the cause, and that someday they’ll be fixed that irritates me. It’s a type of prejudice not born in evidence. It’s the equivalent of "all feedback is bad" sales pitch for some amplifier designs. It is the boogie-man aspect of this particular line of reasoning that I am against, or that Class D still has anything left to prove to be among the best sounding amplifiers available. Like what you like. Spend money to make yourself happy. But I'm done with arguments like "Bagostino amps are better because they have no feedback" or "Class D switching noise will never let it be as good as ..." Those arguments are tired as can be. Best, E |
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. Sorry. had to vent. Best, E |
Shadorne, 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. :) Best, E |
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. Best, E |
Hi @migueca 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. Best, E |
Hi Doctor_lipp! Yeah, I use it on my subwoofer along with bass traps and other room panels. It is essential for the last two octaves. That’s not what’s being done here. DSP is used entirely for electrical phase and amplitude. The actual speaker/room response is not considered. Quite a heavy handed approach to making an amp perform like an ideal voltage source. Still, proof is in the listening. Best, E |
NAD D 3020 sound quality This is a good performer, a huge step up fro my $20 Lepai 10W/ch digital amplifier. It is extremely quiet and smooth, without grain or harshness but also without warmth. The bass boost is a huge help as my desktop speakers are pretty lean sounding. My previous experience with NAD DACs was pretty negative, but this is pretty easy to listen to. Tons of air and detail. But zero warmth. In this sense it kind of goes towards the Emotiva/Asian processor sound qualities. Kind-of, but not nearly as bad as the worst of them. There's just no sweetness or warmth at all in the sound quality. "Stark" may be a good way to describe it, but without the thin/limited range effects I get from the worst of the Asian designs. Reminds me a lot of the 1990's digital sound, if you took that and cleaned it up a lot. So, killer, top of the pack? No. Quite enjoyable, space saving and feature packed is how I would put it. Best, Erik |
