In 2025, u don't look at which Class it is. If a person wants the best, go for the flagships. And currently, the flagships of quite a few are Class D. Let the ears decide the rest.
Class D is still not as good in 2024?
- Thread starter Analogous
- Start date
bhooshaniyer
Active Member
And the reason for that is they want to reduce their.bom cost and increase profitability as the sales are declining constantly. It's optimization not improvement. So i avoid again.
morerajendra5678
Member
This is one of the most interesting threads. As per my understanding, we have good class A, class A/AB as well as class D amps in the market. Now comes price brackets. Through this thread we can come up with quality Class A, Class A/AB and Class D amps available in each price bracket. This will be of immense help for those who want to have a taste of amps as per his budget and class of his preference.
At the same time there is no denying the fact that there has been immense improvement in designs of Class D amps. But we cannot claim that this is the best design. Has the Class D matured enough? As per my opinion it has otherwise we won't have seen such wide use of Class D amps. Even Class D amps now have been put to service in Pro Audio world to a good extent. This confirms the fact that Class D amps are also reliable and some of them sound good and have other advantages.
It is very true that even for home hifi having Class D amp with tube pre gives excellent results but this is also true for any good sounding Class A and Class AB amps. Adding a tube pre amp adds to the warmth of the sound.
At the end of the day we want to enjoy music. This thread can serve as a guide for someone looking to start audiophile journey, someone looking for upgrade of amplifier, someone wanting to add more warmth to his system.
greenhorn
Well-Known Member
I feel that the reason for less class d in flagships is that ultra high end audio is very niche and most customers are gullible, and class d requires a lot more up front design investment, which may not be immediately apparent to the end user, and may not be recoupable, while a typical design with a few tweaks here and there, snake oil components, exotic materials, some very nice design, a nice sounding transfer characteristic and weapons grade marketing will be more successful commercially with more certainty. It's like trying to sell a Japanese superbike to a Harley Davidson fan with the underlying assumption that a biker would always go for better performance.
So why bother trying to play to a crowd who are inherently suspicious of your approach?
So why bother trying to play to a crowd who are inherently suspicious of your approach?
bhooshaniyer
Active Member
You make it sound like a big organized scam. There are 40 people making stuff and some 400 people buying things. Miniscule market. In that scheme of things even an entry level marantz amp is a niche product made for a discerning user only with limited budget. This whole class d premise is - it has come a long way but never that it's inherently better sounding than class ab/a. It's always some hand wringing and some mumbo jumbo on hypex and implementation. When the best of a new tech is only nearly as good as the old (class ab. Let alone class a and tubes)what's in it for a serious audiophile? This argument that some how the consumers don't appreciate this greatest thing after sliced bread is THE snake oil.
Last edited:
square_wave
Well-Known Member
Not putting this here for argument but to encourage discussion.
NAD’s Director of Technology, Greg Stidsen, had this to say: “Like all amplifier classes, there are advantages and disadvantages to class-D. What is attractive about class-D is its relative efficiency and freedom from the vagaries of parts quality. In a linear amplifier such as class-A or class-AB, parts-matching and very close tolerances are required to get the best results, and even then, there is a limit to performance since the linearity of semiconductors varies considerably with temperature.
“With class-D, it’s more the quality of the mathematics and engineering that determines the performance,” Greg said. “Another way of saying this is that in a linear amplifier the design is fairly simple, but the execution is critical; in a switching amplifier, the design is very difficult, but the execution is straightforward.”
NAD’s Director of Technology, Greg Stidsen, had this to say: “Like all amplifier classes, there are advantages and disadvantages to class-D. What is attractive about class-D is its relative efficiency and freedom from the vagaries of parts quality. In a linear amplifier such as class-A or class-AB, parts-matching and very close tolerances are required to get the best results, and even then, there is a limit to performance since the linearity of semiconductors varies considerably with temperature.
“With class-D, it’s more the quality of the mathematics and engineering that determines the performance,” Greg said. “Another way of saying this is that in a linear amplifier the design is fairly simple, but the execution is critical; in a switching amplifier, the design is very difficult, but the execution is straightforward.”
bhooshaniyer
Active Member
All i will point out is that he seems to be saying that class d is cheaper and easier for his company to design and manage supply chain over class ab/a. Fine, it may be true that it's easier to make dessert than real ice cream. But that's being eerily quiet on how it tastes. I hope they don't say on a hot summer day if you close your eyes and eats it's almost as good as ice cream. And btw is it's cheaper for us to make and it saves the planet and it has longer shelf life and it has less weight and doesn't get spoilt! But it's not ice cream you see.
.
Last edited:
square_wave
Well-Known Member
Here are some industry heavyweights talking about the technologies.
PS Audio’s Paul McGowan wrote: “If you look at class-D, there are limitations you will always have to deal with. One of those, of course, is the analogue low-pass filter at its output, used to remove the switching pulses between transitions. While much wonderful work has been performed on this limitation, especially by class-D’s resident genius, Bruno Putzeys, the fact remains it’s there in the signal path. Another limitation is the dynamic range. In a typical PWM-modulated signal running at 100kHz or so, you’re basically limited to about 16-bits of resolution, about the same as a CD, which ain’t bad, but still.
“On the positive side,” he added. “The linearity of a class-D amplifier will almost always exceed that of an analogue-based power amp. They are different, and they sound different. In our products that use class-D output stages, we work with them, as we do all our circuit topologies, in the same way a fine wine vintner [works his wines]. We blend this and that to come up with an award-winning output. For example, in our class-D amplifier Stellar line, we use an analogue input stage to feed the PWM modulator. In the lower wattage models, that input stage is sweetened [using] low feedback FET designs, while in our highest wattage model, the M1200 monoblock, we add a tube input stage to perform a similar function.”
“Analogue power amps, too, have their limitations or quirks,” Paul said, “which we also solved in the design by blending the proper amount of technology and topology to come up with winning design choices, all in service of the music.”
He concluded: “I think using class-D technology for the power supply, as opposed to the huge analogue transformers, etc., and using analogue output and input stages for the audio signal is likely the best topology currently available today. Time will tell if that reverses or changes.”
----------------------------------------------------------
Belgian engineer and Kii Audio co-founder Bruno Putzeys
About that resident genius Paul mentioned—Belgian engineer and Kii Audio co-founder Bruno Putzeys. I think it’s fair to say that class-D amplification would not have the status it has today if not for the fact Bruno spearheaded the class-D revolution with his Hypex UcD and Ncore class-D designs used by most high-end audio manufacturers today. I also doubt that, if not for Putzeys seminal role in making class-D sound as good as it does, that the tube designer I spoke of at the start of this piece would’ve told me what he did that blew my mind.
When I asked Bruno if he’d be willing to contribute a paragraph to this discussion about class-D’s future, he sent me his response with an intriguing foreword: “I do hope you can afford me a few more words than a paragraph, particularly because I’m fairly certain that it’ll run directly counter to at least some of the other replies you’ll get.
“To be completely blunt,” his response began. “State-of-the-art class-D amplifiers are good, not because they’re class-D, but in spite of it. I chose a career in class-D because I liked the [the technology’s] efficiency and compactness, and I was hoping to combine that with high fidelity.
“My first attempt immediately sounded appealing and engaging. The idea that class-D sounded ‘harsh’ was never true and was only perpetuated by people who’d never heard one. As proof of that, rudimentary zero-feedback designs still regularly hit the shelves and garner praise on account of their striking sonic character. But Hi-Fi, they were not. I wanted an amplifier you couldn’t hear, one that anyone could use and be happy with in any stratum of the market. And that turned out to be inordinately difficult [to design].
“The secret lay not in the power stage but in the control circuit, i.e., the modulator and the error correction. The mathematics required to fully understand a class-D amplifier is similar to what’s used in sigma-delta AD/DA chips, only more complicated. It’s not taught at any school. But the change you can make by only tweaking the power stage (faster FETs, etc.) is tiny compared to the effect of better error control. So, mathematics it was.
“Designers of traditional amplifiers are not known to geek out on mathematics,” said Bruno. “They wouldn’t have to anyway; it’s not that difficult to build a respectable class-A amplifier using nothing but a few well-worn rules of thumb. The result was that while class-D crept steadily forward, class-A pretty much stagnated.
“This has caused a curious paradigm reversal,” he continued. “The question is no longer whether class-D is approaching the quality of class-A, but how many class-A amplifiers can really claim to be up there with the best of class-D? Make no mistake, the fundamental fact still holds: any given level of performance is much easier to achieve in class-A than in class-D. But designers of class-A amplifiers have, by and large, sat on their laurels. I could easily design a better class-A amplifier, but I see no one waiting for a better petrol engine.
“The level of difficulty explains why virtually all demonstrably good class-D-based products use prebuilt modules,” he wrote. “The effort of working this stuff out only ever pays off if you can re-use the design in hundreds of products. That’s a mixed blessing. On the one hand, class-D modules have turned high-end amplification into a commodity. On the other, it’s still de rigueur in the audiophile market to have distinguishing (i.e., home-grown) technology. Mine and my competitors’ work of decades raising class-D to adulthood now lends a halo effect to any class-D amplifier. Today, almost any class-D amplifier gets a rave review, no matter how crude the design. This could well prove perilous in the longer run to class-D’s hard-won reputation.”
He added: “[One] way to escape from this is for the audiophile market to [focus less on] separate components. If you want to know what’s scaring younger customers away, it’s the idea that they should suddenly school themselves in amplifiers, DACs, cables, and whatnot before they can buy something that plays quality sound. Active speakers are a way out of this. If high-end audio has a future, it’s in system [integration], where the amplifier is simply a necessary functional block but where the real cleverness lies in the concept of the system as a whole and how it functions, sonically and practically.
“There is a whole future in front of us with radically improved sound systems,” said Bruno. “If only the market were ready to accept that the amplifier part is basically a solved problem.”
PS Audio’s Paul McGowan wrote: “If you look at class-D, there are limitations you will always have to deal with. One of those, of course, is the analogue low-pass filter at its output, used to remove the switching pulses between transitions. While much wonderful work has been performed on this limitation, especially by class-D’s resident genius, Bruno Putzeys, the fact remains it’s there in the signal path. Another limitation is the dynamic range. In a typical PWM-modulated signal running at 100kHz or so, you’re basically limited to about 16-bits of resolution, about the same as a CD, which ain’t bad, but still.
“On the positive side,” he added. “The linearity of a class-D amplifier will almost always exceed that of an analogue-based power amp. They are different, and they sound different. In our products that use class-D output stages, we work with them, as we do all our circuit topologies, in the same way a fine wine vintner [works his wines]. We blend this and that to come up with an award-winning output. For example, in our class-D amplifier Stellar line, we use an analogue input stage to feed the PWM modulator. In the lower wattage models, that input stage is sweetened [using] low feedback FET designs, while in our highest wattage model, the M1200 monoblock, we add a tube input stage to perform a similar function.”
“Analogue power amps, too, have their limitations or quirks,” Paul said, “which we also solved in the design by blending the proper amount of technology and topology to come up with winning design choices, all in service of the music.”
He concluded: “I think using class-D technology for the power supply, as opposed to the huge analogue transformers, etc., and using analogue output and input stages for the audio signal is likely the best topology currently available today. Time will tell if that reverses or changes.”
----------------------------------------------------------
Belgian engineer and Kii Audio co-founder Bruno Putzeys
About that resident genius Paul mentioned—Belgian engineer and Kii Audio co-founder Bruno Putzeys. I think it’s fair to say that class-D amplification would not have the status it has today if not for the fact Bruno spearheaded the class-D revolution with his Hypex UcD and Ncore class-D designs used by most high-end audio manufacturers today. I also doubt that, if not for Putzeys seminal role in making class-D sound as good as it does, that the tube designer I spoke of at the start of this piece would’ve told me what he did that blew my mind.
When I asked Bruno if he’d be willing to contribute a paragraph to this discussion about class-D’s future, he sent me his response with an intriguing foreword: “I do hope you can afford me a few more words than a paragraph, particularly because I’m fairly certain that it’ll run directly counter to at least some of the other replies you’ll get.
“To be completely blunt,” his response began. “State-of-the-art class-D amplifiers are good, not because they’re class-D, but in spite of it. I chose a career in class-D because I liked the [the technology’s] efficiency and compactness, and I was hoping to combine that with high fidelity.
“My first attempt immediately sounded appealing and engaging. The idea that class-D sounded ‘harsh’ was never true and was only perpetuated by people who’d never heard one. As proof of that, rudimentary zero-feedback designs still regularly hit the shelves and garner praise on account of their striking sonic character. But Hi-Fi, they were not. I wanted an amplifier you couldn’t hear, one that anyone could use and be happy with in any stratum of the market. And that turned out to be inordinately difficult [to design].
“The secret lay not in the power stage but in the control circuit, i.e., the modulator and the error correction. The mathematics required to fully understand a class-D amplifier is similar to what’s used in sigma-delta AD/DA chips, only more complicated. It’s not taught at any school. But the change you can make by only tweaking the power stage (faster FETs, etc.) is tiny compared to the effect of better error control. So, mathematics it was.
“Designers of traditional amplifiers are not known to geek out on mathematics,” said Bruno. “They wouldn’t have to anyway; it’s not that difficult to build a respectable class-A amplifier using nothing but a few well-worn rules of thumb. The result was that while class-D crept steadily forward, class-A pretty much stagnated.
“This has caused a curious paradigm reversal,” he continued. “The question is no longer whether class-D is approaching the quality of class-A, but how many class-A amplifiers can really claim to be up there with the best of class-D? Make no mistake, the fundamental fact still holds: any given level of performance is much easier to achieve in class-A than in class-D. But designers of class-A amplifiers have, by and large, sat on their laurels. I could easily design a better class-A amplifier, but I see no one waiting for a better petrol engine.
“The level of difficulty explains why virtually all demonstrably good class-D-based products use prebuilt modules,” he wrote. “The effort of working this stuff out only ever pays off if you can re-use the design in hundreds of products. That’s a mixed blessing. On the one hand, class-D modules have turned high-end amplification into a commodity. On the other, it’s still de rigueur in the audiophile market to have distinguishing (i.e., home-grown) technology. Mine and my competitors’ work of decades raising class-D to adulthood now lends a halo effect to any class-D amplifier. Today, almost any class-D amplifier gets a rave review, no matter how crude the design. This could well prove perilous in the longer run to class-D’s hard-won reputation.”
He added: “[One] way to escape from this is for the audiophile market to [focus less on] separate components. If you want to know what’s scaring younger customers away, it’s the idea that they should suddenly school themselves in amplifiers, DACs, cables, and whatnot before they can buy something that plays quality sound. Active speakers are a way out of this. If high-end audio has a future, it’s in system [integration], where the amplifier is simply a necessary functional block but where the real cleverness lies in the concept of the system as a whole and how it functions, sonically and practically.
“There is a whole future in front of us with radically improved sound systems,” said Bruno. “If only the market were ready to accept that the amplifier part is basically a solved problem.”
reignofchaos
Well-Known Member
No one here is talking about how class D modules are basically use and throw with zero repairability - anything that dies goes straight into the landfill or the fact that these devices require a crazy amount of negative feedback to stabilize which robs music off the harmonics that make music feel real.
morerajendra5678
Member
Does this mean that there cannot be a good sounding Class D amplifier? But there will be some otherwise there would not have been such wide use of Class D amplifier. Might be the case that some implementations have found a methodology to make the Class D sound good inspite of its need to stabilize it with negative feedback.
I use tube amplifier. There are good push-pull amplifiers and by design push-pull amplifiers use negative feedback. So I believe it boils down to implementation part.
I love the way he points out how we may be mistaking the forest for the trees…
So many variables combine and contribute to produce the sound in any music set up.
The end result is how the listener feels during and after the experience. And that too varies depending on the mood of the listener, the expectations, the company he/she listens with, the visual aesthetic, the amount invested, the listening experience and skill and preexisting biases.
We may ask “where’s the fun in active speakers?” But Putzeys tactfully segues to “younger customers” who are the future market without getting at older customers who have grown up with older and matured tech, who are most likely to be set in their beliefs, opinions and convictions.
Thanks for sharing this insightful post, @square_wave
Decadent_Spectre
Well-Known Member
If that is how you/people define listening to music then the people who think this have missed the point of music. Second if this is how you define listening to music then I have perfectly understood your thought process, thank you for this information.
Do explain
Decadent_Spectre
Well-Known Member
Oh there's nothing to explain, I am semi retired from forums, I came on here, saw a post, and randomly posted. It's all in English. Have a good one.
Just make some puzzling comments and retire when requested to explain?
Maybe better to explain your viewpoint a bit?
After all we do respect the right of every one to have an opinion even if it doesn’t align with ours.
Decadent_Spectre
Well-Known Member
Oh no, feel free to browse my posting history I reckon I haven't been posting much for a while.
Like I said it's all in English.
greenhorn
Well-Known Member
Does anyone know why true digital amplifiers like the sharp sm sx100 died out? While i can't afford one, I have a e1da powerdac and it sounds amazing
greenhorn
Well-Known Member
There was a meme on the very first page saar
Thank you. I just might do this,…probably not today.
bhooshaniyer
Active Member
Whats the impediment to full retirement?
Get the Award Winning Diamond 12.3 Floorstanding Speakers on Special Offer
