Found a partial answer: NAD calls the D 3020 a "hybrid digital amplifier," by which they mean that not all of its circuitry is in the digital domain. The D 3020 combines a Cirrus Logic DAC (eight channels mixed down to two) with a class-D output stage designed by Hypex, of the Netherlands. According to NAD, the output stages aren’t fazed by low-impedance speakers.
Hard to interpret exactly which part is which though, especially since Bruno Putzeys bristles if you call his amps "digital." Still, I will guess this is at least not a Hybrid a'la nuForce or Yamaha EEEngine, but something else. https://www.stereophile.com/content/nad-d-3020-integrated-amplifier-sam-tellig#1FLoXpsCMuhoTAk1.99 |
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
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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
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Could be. But it could also be in addition to.
Looking at the specs for the B&O amps for instance, they could benefit from this idea.
Also, as I have noted, you CAN do this yourself using miniDSP, if you were so inclined. I wish I had the time/space/energy, it would be a fun project.
Best,
E
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hi @autre
Glad you found this thread useful and that you bought something you like.
Remind me please, what are you comparing the Red Dragon to?
Best,
E |
Thanks for the link @sfseay
Best,
E
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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
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Hi @ejr1953
I have not, but I am a huge fan of the Brooklyn Pre/DAC!
Best,
E
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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
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Hi @jaymark,
You are kind of hitting on a topic I’ve written about here for a bit, which is habit, taste and training our brains to appreciate different things.
For whatever reasons, my brain is wired quite the opposite. I don’t like the sound Pass amps make and often prefer other brands, and many Class D amps.
There’s no right or wrong, you can’t convince me to like a Belgian White ale either. :)
Best,
E
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I must say that for any amplifier, the PS Audio Stellar's measure poorly.
Most Class D amps I know of do considerably better. I'm more than a little surprised PS Audio put that out there.
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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
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Sorry 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
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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
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@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
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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 |
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
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@georgehifi
And no one is more invested in making sure they know you don't like Class D than you are.
Best,
Erik
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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 |
OR.....Ayre monoblocks for totally different reasons.
The CJ8's are juicy as hell. The Ayre warm to dark. |
Sorry bluesy41,
My experience does not match yours at all.
I've heard many Class A which I liked less than the Parasound A/B amps, and those are the equal of the Class Ds I have now. I think the idea that all Class A is better than all class D is nonsense.
Best,
E |
Parasound Fatiguing?? Hahahaa. Some of the warmest A/B amps out there. Run Class A most of the time. And yeah, I've heard _some_ pure class A amps they beat hands down.
Unless of course you measure sound quality by money spent. Then of course, only Class A will be pricey enough for your ears.
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 |
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 |
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I do not. I have the v1 which has a USB input instead.
Best,
E |
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. |
@celander
Oh, I don't mind that. I'm not hear to convert anyone.
But I think it shows a great deal of class when you speak your peace and then leave the subject alone for those who are contributing in a positive fashion.
Best,
Erik |
I am really not a fan of silver over copper cables.
However, solid silver interconnects are pretty good and inexpensive to build on your own.
Best,
E |
@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. |
A class D a o into 2 Ohms or less is just ear bleeding, cynical, no depth, headroom is nonexistent,
devialet, and all this super high dollar stuff is just bad! Well that’s interesting since so many of us routinely listen to 1 or 2 Ohm speakers, I’d like to know what amps and speakers he reviewed to come to this broad opinion. Hahahaha. |
Hi @eddiet
I never heard one. Ended up with the NAD equivalent and very happy. They use a hybrid , almost like a Class H, Class D and Class A in one, designed by Hypex. No, the new transistors won't make anything obsolete, but sure will make things more expensive.
Erik |
