How to make Class D sound better
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- เผยแพร่เมื่อ 21 ก.ย. 2024
- Class D amplifiers can be among the best and worst sounding amplifiers made. What makes the difference in sound quality between these two extremes? Have a question you want to ask Paul? www.psaudio.com...
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I love to watch this channel so I can repeat things that were said but I don’t know what they mean.
People think I’m smart.
I've owned a Crown xls1002 class D power amp for two years. In the beginning I plugged my cheap-but-good Behringer UCA202 DAC straight into the crown and it sounded okay-good with two pair of pioneer andrew jones speakers wired in parallel. Then I bought a brand new Behringer MIC2200 two channel tube preamp for $100. It has a single 12AX7 tube, a dual triode tube so it provides two channel stereo in a single tube. There are better preamps out there, but this was all I could afford and it made a huge improvement in sound quality. It has parametric EQ for each channel and sounds really clean crisp smooth and powerful for a small cost. The pioneer speakers are one pair of the bookshelf model stacked on top of one pair of the towers. Set up this way these speakers sound amazing for their low price, great bass, and can handle playing loud without distortion.
I want to buy the crown xls 1002 for home use. But i saw that the xli 1500 at almost the same price delivers 100watts per channel more...i know xls is class D and has a built in dsp,and the xli is a class ab... i am in a dilemma my friend can you pls give me an advise
@@ΛουκάςΚλαρνέτατζης Before Crown started making class D equipment, they produced class AB amplifiers geared towards professional uses such as live music, concert venues, stadiums, night clubs, houses of worship. These high power pro applications use a type of AB circuit design which is less optimal for critical high-fidelity listening. But today's class D works well for both professional use and hi-fi listening. I'm not an expert in electronics. These are my own conclusions after having set up and run pro-sound systems for touring musicians when I was younger, and being interested in music and hi-fi equipment for many years. In my view, better speakers and a tube preamp make more of an improvement than more watts.
@@mikeday62 ...so you think for home use i better stick to the xls than the xli? also i hear the class D almost never uses the fan so no noise from that cause no heat,the a-b class will hava that noise am i right?
@@ΛουκάςΚλαρνέτατζης When the music is playing loud, after six or eight minutes the fan in my XLS-1002 comes on for one minute, then stops for several minutes, then on again for one minute. The case is never warm, always cool to the touch. The fan is silent. Even if you turn the sound off, the fan makes zero noise. Yes, the AB fan might make more noise. Class AB made for hi-fi sound are great amplifiers. Yes if you want a Crown, then get the XLS. Mine has plenty of power for me. If you have the money, get the XLS 1502, or larger. 😁
@@mikeday62 thank you for your replies,you have been very helpful!
Hey Paul, really like all your informative audio information! When l purchased my Maggie's. 7's I decided to buy a used class D amp (I already have a VAC PA 100 100 tube amp) and in the event I didn't like it, l wouldn't lose too much money. I came across a Spectron musical MK ll class D amp that was designed by John Ulrick back in the early 2000's From what I understand John basically invented the class D amp
He also worked at Infinity speakers with
Arnie Nudell and developed the class D amps on the Beta RS speakers. Before I bought this amp ( for less than a set of decent set of speaker wires) I read a lot of reviews, and all the reviewers loved it!
It's a beast! Coming in at 54 lbs has the ability to output 1,200watts@1ohm and 65 amps for 500 milliseconds I must say for an old D class amp it sounds pretty close to my VAC but with much more dynamics and effortless power
Paul have you heard of, or know of this amp?
It seems like people say class D amplifiers hiss. Like I'm thinking of the JBL 305P speakers and similar. They all seem to hiss quietly and people say it's due to the class D amplifier. I don't see what it is about pulse width modulation that causes hiss.
Excellent explanation. Sorry, I'm an old fart and never thought that this is where the high end amplifier market had gone. Class D modules. For some years I was friends with, and a customer of, Nelson Pass ( then Threshold Audio now Pass Labs ). One feature of a Nelson Pass Class A amp is during cold weather you didn't need to turn on your furnace while you were listening to your stereo. Make sure you use a 20A 115vac wall socket on a separate circuit breaker.
Bill Kenney
I hate listening to the furnace when listening to music, so my class A mono blocks are really cozy. Not so great in the summer months, but class A sounds so sweet. I'm surprised so many people are willing to sacrifice quality for class D amps. Do these people realize when they do a load of laundry they use more power than probably several months of listening to music. We are talking pennies for a Kw/hr, so why would anyone sacrifice sound quality to save a few pennies per month. There are far better ways to save electricity. Class D amps don't sound good to me.
@@gordthor5351 Not any more. Two 100W amps are gobbling 200W/hr when not being listened to. And have you heard of climate change? Those wildfires? That drought? Yep - "pennies". Times 240,000,000 people in the USA alone swiftly adds up. Besides, when companies that supply some of the best studio monitors in the world like Adam Audio are using Class D, the argument for class A boils down to what you've already invested in. And heat isn't just the enemy of human existence. Heat kills electronics, that's an undeniable fact proven over numerous decades.
@@2112jonr You don't know what you are talking about. My amps are off when I'm not listening, so they aren't "gobbling up" nothing. Unlike you I actually understand electronics and can repair electronics. It is NOT a fact that "heat kills electronics". If that was the case soldering the components to the PCB would kill them.
Excessive heat can damage certain components, and that is certainly not the case with my well designed amps. I can touch the heatsink on my mono blocks. Have you ever seen how hot many class D heat sinks get?
Yeahm I am well aware of climate change and I do what I can to do my part. Real differences, not saving 15 cents worth of electricity a week for my stereo.
I hope you hang your close out on the line instead of using 4500 watts/hr to dry one load in a dryer. If not you are a hypocrite and your piss ant savings on a class D amp will do nothing substantial to fight climate change.
Also, the vast majority of people (99%) don't give a rats ass about audio quality, so your assumption that 240,000,000 people are going to run expensive mono blocks is ridiculous.
I bet my net carbon footprint is smaller than yours, and especially your country's (absolutely pathetic) carbon footprint.
Go teach some far right wing Americans about climate change. They need it. I don't.
Class A circuits, by default, are biased in the middle of their linear region. Which, at idle, is running about fifty percent of their current capacity.
well, no, the signal is AC and the 0 signal is the full conduct signal. Based on the quality of sound I do not care if i have to pay another penny for consumption of electricity or create more heat.....that is for the internal heat sink to manage.
all I say is that you cannot beat high end class "A" Amplifier
Paul, I run a tube guitar amp repair shop in S.F. but I used to work at H.H. Scott in Wouburn ,Mass. in the 80s. It wasall manufactured in Asia. I was bench tech and I got to know two of the old engineers Don Merriman and Peter Globba. I would bring in tube guitar amp drawings and they would say tubes went out with the horse and buggy and then they'd start talking about them in great depth. Peter and I had a discussion that I'll never forget. Peter worked for the Germans in WWII. After the war he moved to Brazil and worked in a radio factory. He said that they made their own capacitors,probably had to. He also said that there were cardboard shacks next to mansions.The poor people were lucky to have some beans and rice to survive on.He made it sound like communists were trying to convert people to their cause. He also said that nobody cared about capitalism or communism, they just wanted to eat.The sad thing is that's S.F., Ca. today, cardboard shacks next to Refined Residences. What happened to this country ?
This country? What country?
Sierra leone?
What is the name and address of your repair business
Rich senators took Russian money to undermine your democracy. Same in the UK.
There's your answer.
thanks for your class A amp heat explanation here. Now I understand !!! doh! I have a Marantz SM8 /3250B still working in my study system. Most, but not all the central heating that's required in winter. Best wishes from a chilly Montreal.
Actually a very good explanation of what the problem is with Class D. Greetings fellow Alumni Valencia HS Paul!
Valencia High School? No way! Thanks for posting. What year did you graduate?
@@Paulmcgowanpsaudio 1991 Paul. Great videos! Keep them coming!
Heat is also the enemy of electronics; therefore, I have heard Class D amps that produce beautiful, detailed sound with high voltage that do a wonderful job. I personally have compared expensive monoblocks to a relatively modestly priced Class D amp and found it to be much more musical, detailed, and very pleasant to listen to with accuracy and also much more versatility in usage. There is a LOT of hyperbole in advertising, technical mumbo-jumbo, and people lap it up . . . it is like a status or snobbery to own and to be able to afford the most expensive -- and like designer labels, which may not necessarily be the highest quality, these brand names certainly demand the highest price tags. You CAN get what you paid for . . . but if you are a smart shopper, who has replaced snobbery with practicality in achieving the same results -- if not better, you can find the “designer labels” on the close-out rack for a lot less money than when they were first introduced to the public -- even if their labels have been cut-off, they are still the very same quality product at a much more affordable price, which to me, who could care less about impressing anyone but myself, is a much better deal.
Think for yourself . . . research, compare, prove to yourself what is the best sounding products . . . and if your snobbery is much more important, much more impressive and convincing to your ears, then the actual product you enjoy in your home -- then the only person being impressed and fooled in the process -- is yourself.
Could you offer some specific examples of products that produce this wonderful musical, detailed, accurate sound for substantially fewer bucks, not to mention lower operating costs? I'm thinking about re-modifying my MOSFET class AB amp (a Hafler which I think is completely non-original except for the output transistors and the power switch). But I'm open to a different approach, i.e. a newer class D. My power needs are not great due to room size and the volume at which I listen.
In my opinion, which is certainly up for dispute, is that the Crown XLS Series is worth looking into for those characteristics. I owned for many years the Hafler 500 and also used the B&K monoblocks . . . even enjoyed the warm sound.
I heard the Crown amps used on an active crossover sound system at an individual's home being run through a DBX DriveRack PA1. When my amp that was running the subwoofers (which I bought 2nd hand) went out on me . . . I bought the Crown XLS 1502 and was so pleased with the QUIETNESS, not to mention the detail, imaging, and sound staging I received. As I am able, I may also take my system to a multiple amp active system. I am using the DBX DriveRack PA2 to equilize my speakers to my listening room -- also worth investigating its capabilities.
There are various models of the Crown. The Crown XLS 1002 is $299.00 and can be financed at $7.00 a month for 48 months interest free at Sweetwater. I am not affiliated, except as a satisfied customer. Here are some of the specifications of this class D amplifier:
Watts/Side @ 8 ohms: 215W
Watts/Side @ 4 ohms: 350W
Watts/Side @ 2 ohms: 550W
Watts Bridged: 1100W @ 4 ohms, 700W @ 8 ohms
There are other good brands . . . this is the brand I bought.
There are also on TH-cam some reviews and demos for you to watch. Best to you.
I strongly agree with your message. I have the crown xls 2502 amps. They sound just as good as emotiva, outlaw audio, monoprice amps Etc. there are better deals out there for a wonderful price point.
russmaleartist Not even close to a real hifi amp. I've heard many and would not consider class D even close to high fidelity. They make good public address or subwoofer amps but that's it. You would be much better with class A , B or class AB.
We all have our opinions, and since I do not recognize you as an expert or authority on what I enjoy listening to for my many years; furthermore, have you listened to everyone's amplifiers in every circumstance and combinations? I doubt it . . . so, we will have to agree to disagree. Perhaps some are due to budget and compromise, but then even those who are considered “experts” will tell you that sound reproduction still doesn't come anywhere close to the real thing . . . perhaps close, but there is still something missing.
I no longer have any Hi-Fi salons near to my area, but when I did, there were quite expensive brands of amplifiers, etc. to listen to . . . and they sounded great, but even they were spoken of by reviewers and experts as controversial. I mean, when I subscribed to Stereophile and the Absolute Sound. One month pieces of equipment were to die for -- the next month, they basically were equated to yesterday's newspaper only fit to wrap fish or line a birdcage. I never fathomed that mentality of how something could become so outdated in such a short time . . . nor how anyone could keep up with technology. If you can -- more power to you.
I have listened to tube amps like Audio Research, and even built the old Hafler 500, which was considered a competitor in its day . . . and have used and still use monoblocks by B&K . . . and I do believe that there is always something claiming superiority, but soon falls from grace -- the point being, we all have ears to hear, but that doesn't mean all ears are equal, any more than money automatically gives one good taste nor the superiority as being the final word on anything. In my many years, I have found that mankind, no matter how opinionated, is still fallible, extremely ego-driven, and do not like to be contradicted . . . too bad, because each of us would like to consider our opinions as valid as another for various reasons, and owing to the fact that none of us are going to agree 100% on anything -- even within families.
I believe debates are profitable and the hobby is kept alive by the improvements and all the hype and claims by manufacturers, but I would suppose the point is that although I agree with having opinions . . . but if one is convinced that their system is the best -- with the countless combinations of turntables, cartridges, tonearms, preamps, amps, speakers, wires, and such -- I would venture to say that it is physically impossible to be in a position of comparing every combination of what people are currently using or inventing and come to a definitive conclusion that theirs is the ultimate best. You cannot, because we all know that little changes can make a big difference even in our own system's reproduction on any given day with a repositioning of a speaker to the change in humidity, furnishings, room environment, let alone all the endless and impossible combinations of everything being equal in one's listening experience, their ear accuracy, etc. -- too many variables for even the most capable, educated, self-proclaimed experts, and/or publically respected individuals who claim to “OWN THE BEST” to ever really justify such claims -- no matter how much money they have spent on their equipment, listening room, etc..
Who has the right to be KING OF THE HILL when it comes to this industry and hobby, when such a position doesn't exist? There is always someone more clever and capable of claiming such notoriety, until the next individual claiming such, and then the next, and so on . . . for the chain of claims is endless. Enjoy the music and leave the dogmatic claims for those who are foolish enough to take on such an impossible challenge. I like my Crown XLS 1502 Class D amp in my system very much -- and quite frankly -- that is all that matters!
Hypex stuff is technically amazing. The TI TPA3250 series of chips is what I use in my system. They sound very good btw enough that I don't use the Neurochrome amps that have superior audio quality but are a power hog in comparison to class D systems
yes you are right ! good that you share your experience with us ! Thank you. But there is no secrets if someone can read. Most of the principles to build good audio gear I found in the old 1968 -1980 databooks from various Semiconductor companies...
Could you talk more about what the input stage does? In other words, how does it affect what's coming in?
5:15 answer to the question
I feel this also has a lot to do with the caps used, how many microfarads per channel, crosstalk issues, slew induced distortion issues so on and so forth.
Class a is the best heat generator but also sounds far better than class d or ab. Heat dissipation is an issue but , hey, audiophiles make such big investments in gear, dedicating space so what׳s the cost of say 100kwh per year (500h of listening at 0.2kw consumption) we are looking at around $15 plus one third more for the aircon to dissipate the heat. My main issue with my Pass F6 was my wife who stated “no way you stick this at home it’s much too big” but finally we worked this out and we both gets to enjoys superb sound!!
Well that didn't answer anything. The Achilles heel of Class D is its output stage. The output filter network interferes with the effectiveness of the feedback loop to do its job. This causes many problems.
Good explanation Paul. I hear the biggest differences in Class D amps because of what is being used for the input stages. The Hypex NCore NC500 Has a socket for the input stage. You can change it in minutes and get a different sound: different IC OpAmps, or discrete OpAmps. Kind of like tube rolling.
Julia Set The input stages have nothing to do with the ClassD designation of the amp. Most (if not all) input stages are ClassA voltage amplifiers.
Yes, I may have not stated my point correctly. The NC500 has a socket for the input stage that can accept any number of IC OpAmps or discrete OpAmps: these do the voltage amplification before the Class D stage. The IC’s are probably not running in pure class A, but I think some like the ubiquitous NE5534 do have a high bias. Most of the discrete OpAmps run in Class A. sparkoslabs.com/discrete-op-amps/
Julia Set I checked that link.... Now, you don't have to take my word for it of course, but just stick with an ElCheapo NE5532 OPA2134 and you'll be just fine. That whole site reeks of snakeoil..... $50 for a $0,50 voltage regulator ..... A joke at best. In reality... a rip-off!
BTW, after going back to the Hypex documentation, I think the input amp is not on a socket but on the header plug, so one may have to add their own socket. I have a Nord amp which has all of that stuff on a separate input board with a socket.
Julia Set Yes, I got that. I checked the docs as well.
What PS Audio can do is to switch to hypex modules. Because of 10-20 dB lower distortion level and few times more high switching frequency with comparable price. ICE is over. And to fix an unbalanced input, so both produce a scene of the same width.
Could you do a primer on Crown Class X amps? I think they are a variant on A-B. I know they reuse energy sort of like a turbocharger in a car. I have a XTI 2002 and Love it. I am running from a Xfi HD titanium pro sound card through a DBX Driverack PA and a BBE sound maximizer. I had replaced a Behringer crossover with the DBX and that was a huge improvement from a preamp perspective.
I run a xtz edge A2-300 and ordered a pair of magnepan lrs speakers. I hope they match.
Hi there -
Have been led to understand that the PWM output from a class D may either be integrated into an analogue output either by a large-ish (~1000uF) capacitor across the output, or, alternatively, actually just by the inherent (mechanical) integration of the speaker itself -
- thoughts?
Although I have a pair of Krell KMA-160 monoblocks which do sound great, and they also do generate a great deal of heat, I usually run a pair of QSC MX1500As in a 2x2 biamped configuration and I'm telling you that I just can't be sure if they sound any different from the Krells. The QSCs are not Class D, but they have a two level rail voltage system to improve efficiency. The rail voltage switches to the high range when program levels demand it. They run pretty cool but not ice cold.
What I wonder is why with car audio class D amps (even the ones designed specifically for subwoofer duty) does the low end of the audible range seem to alway be modified by the amplifier to prevent good sound quality? I'm not talking about the subsonic filter they usually have. I installed many class D subwoofer amps during my time with an electronics company and it seemed class d amps either always had weird things happening from 40 or so hertz and down, and/or their phase was frequently way off from the mids and highs amplifiers.
I'm looking into a class d for subs, to save space in my vehicle, to run along with my class A that will be running mids and highs, but I'm worried it won't ever sound accurate. Any of my AB amps have always sounded amazing but take up too much space for my current vehicle.
Class A is like driving a car at full throttle and using the brakes to control the speed,just like modern mastered CDs.
Yes, but you don't feel the gears change as much (read crossover notch distortion)and if reducing that is the priority you might accept such an asinine approach if it's the best you've got.
The problem with modern produced music is that they are mastered for use in noisy environments like cars. Same with radio. I can appreciate the motivation behind it but I think a better way would be to provide an opt in/out function so if you want to listen while mowing the grass choose one way and if you are going to sit down at home and focus on the music you should be able to hear the dynamics of the original performance.
@@InsideOfMyOwnMind nope. Mastering engineers are not changing the entire basis of mastering to take account for noisy environments. They are doing the same they always have, correcting balance for maximum translation, checking technicalities such as phase, making adjustments for specific formats (viny basically, with has physical limitations to deal with). Topping, tailing, possibly track sequencing, aiming for tonal and dynamic consistency... I work as a mastering engineer, and I don't think once have any of my peers stated that they are suddenly changing their process to master for noisy environments...... Whatever the hell that means.
Thanks well put,someone didnt get what I stated... I see....mastering is a bitch you know its wrong but the client always wants it louder(customer is always right aye..not).
Perhaps I over generalized. I respect your knowledge and input.
@@paulphilippart7395 the loudness wars are over. Clients are much better informed. The -13LUFS standard of streaming platforms and online vendors (including TH-cam) has helped, as clients have a solid reason for not having rammed levels. As radio has become irrelevant now, as a musical medium, the race to be loudest is basically over. There is still a little leftover in the vinyl industry, mainly dance music, where cutting at +3volts is considered a must for a loud cut, but less and less DJs play vinyl now. Generally, in terms of Dynamics, things are getting much much better compared to 10 years ago.
There is a lot of audiophoolery in the audiophile world. I always find it funny the stuff that audiophools will spurt out and declare or argue over. A good deal of this stuff is not stuff mastering engineers worry about, and we require the best accuracy, in general, in the production process.
The things that have the biggest, most noticable effect on the purity of sound are speakers, and then the room. If people are arguing over sound quality, desperately swapping 1000 dollar cables around, and messing about with overpriced power cables, but their rooms are untreated in terms of room tuning.... Then it's all bull and they really don't know what they are talking about.
No mention of switching frequencies?
ELAC uses a Class A input stage. Harman rolls their own modules for JBL, Mark Levitson, Crown, etc.
I am busy with a 5 and a 8 level amplifier who has postfeedback with a PID controller, making the fase correcties right because of lowpass, is difficult.
..im very new to this but what if you sent that wasted power of a Class A into caps instead of heat sinks for AC regeneration as in a built in mini power plant inside the amp itself
Hi Paul, I learn so much from your videos. A question for you. Is there any latency when a Class D amplifier needs to call-up more power for say a louder passage and are there any audible signatures when this happens?
Nope. The typical switching frequency for a SMPS is 100kHz or higher, way out of the band for human hearing.
@@Paulmcgowanpsaudio in theory higher switching frequencies (in the MHz or even GHz band) would be better as you get higher resolution on high tones, but i know that drive circuitry, filtering, layout design (against interference etc), design capacitance and a ton of other things matter
but yeah, a 200kHz switching frequency will only leave like 10 points accuracy for a 20kHz sound signal, especially for studio applications it sounds counter intuitive with 24 to 32 bit 192 to 384kHz to use only a switching frequency of 100-150kHz, not like you'll really hear you've only got 10 data/switching points at 15kHz but it could be an argument, also switching at really high frequencies in the order of a few MHz to GHz also really kind of removes the need for chokes on the output, possibly increasing the efficiency as it doesn't get filtered through inductors
that makes the TI TAS6424-Q1 quite interesting apart from being an IC and not having the best crosstalk nor sampling rate (96kHz digital input... yeee) www.ti.com/product/TAS6424-Q1
but that frequency could make for an interesting amp if you can find comparators etc that are fast enough to handle/compare audio to the carrier frequency with a great resolution, ADC's sound kind of counter intuitive if you want to reproduce audio at these kind of frequencies while wanting a perfectly similar amplified output (apart from the switching) as compared to a really old record (pre digital) on a class A (or AB) amp, 2.1MHz would reproduce sounds accurate enough to have such a high res it's impossible to discern from the original even with special measuring hardware, apart from the coloration coming from transistor amps or tube amps obviously.
Class-D amplifiers have a low power supply rejection. You should take care that you have enough capacitance in the primary and secondary stage of your SMPS and a nice voltage regulation. Also you can have some crosstalk due changes in voltage in the caps due to the other speaker.
One day they might superceed all amplifier types, once output devices can switch at much faster speeds you could in theory negate the output filter
Texas Instruments made one for cars, which has a switching frequency of 2MHz, but unfortunately is low power
The output device at my USB 3.2 port is switching at speeds above 5 gigahertz.
I’m not impressed.
However Class "D" are the most distorting amplifiers ever. They convert the signal into digital that depends on a sampling rate, then it need converting back into Analog to drive the speakers. This is a terrible proposition when you try to smooth that staircase signal on the output, plus try to silence the noisy circuit fill with hundred of switching transistors. They, "D" class are more electrical efficient but who count the penis you can save with a class "D" amplifier over a class "A"???
We like the best sound and saving on the electrical bill is not my goal! Class "A" on tubes are the best sounding amplifiers.
@@russmaleartist Sure, I herd them, they sound good but they do not have the ultimate sound I look for; also, I inspected the output of several of a few high end Class "D" amplifiers on a variety of frequencies on a high resolution scope and you can detect, slightly, the stairway digital output. Moreover, you can detect the transistors cutoff noise by an overshot of the wave. I do medical electronic these days but HiFi is the roots of my carrier. I understand that people do like the equipment they purchase, but there is always something better even if consumes more electricity or produces more heat. Do not get hostile. I expressing my thoughts and back them up with explanations. This is a form of a forum to exchange ideas.
@@mtabernig Funny how having a difference of opinion is called hostile -- did I threaten you somehow? I didn't -- I disagreed . . . why is everyone so thin-skinned -- especially over an inanimate object. I would say, get a grip . . . but I am afraid that it too may be too harsh for your delicate nature.
@@russmaleartist No, you came out on -"how can you make such a blanket statement"- when you did not ask to clarify what did I meant or my qualification to render my opinion.
@@russmaleartist Now who is the Baby????? LOL
@@mtabernig So sorry for people like yourself, who must be right regardless. One gets on a site to share a hobby they enjoy with others and because an individual doesn't agree and can't win a fair debate, they have to try to bate, debase, and defame in order to win an argument. Well, here you are, mtabeernig, “you win” -- what you won, I am not exactly sure -- a trophy for being a arrogant jackass perhaps . . . now go get your diaper changed and come back when you have had your nap and are in a more social mood.
It would have been nice if you have told use how you overcome the problems of class D amplifiers such as high frequency performance.
higher switching frequency
How much higher? A standard delta sigma converter would run at around 3Mhz which is ok for small signals but there are new challenges with higher currents and voltages. I was interested in how those had been overcome.
John Jackson: Youve opened a can of worms there; doesnt matter how high you push that frequency; you will always get an audiophile with superman hearing telling you its too low. There is research paper/s out there to find on blind listening tests though.
The main problem with increasing the output frequency is stray capacitance and such causing a double-conduction state on the output transistors and at those kind of voltages and currents it would be akin to a small explosion.
@@suzesiviter6083 That's an intriguing answer. I would be very interested to see the results of scholarly research on anything relating to perceived audio quality.
Paul, have you ever listened to a MBL Radialstrahler?, I wondered if this is a technology you would deem worthy?
I've always wondered what an amplifier designer chooses to design the power output... as I understand SPL and decibels in order to obtain a 3 decibel increase a doubling of wattage is required however at 90-plus decibels. At 30 to 60 db little power...at 90 db much more power required. Let's say you have a 100 watt amp and a volume scale of 0 to 100 since volume increase and gain isn't necessarily linear when you increase the volume to 50% that might mean in that design it's using 50 watts and increase power to 70% using 70 Watts and then 100% power would equal 100 Watts in a certain design. How do amp designers now usually choose this concept, or design. I have seen so many different brand new companies popping up throwing class D amp modules inside a metal box... and sell for $2000.00 lol. Why doesn't the company making the amps just throw them into a box themselves? I like the Pascal amp modules from Denmark lately. Great thd proprietary input buffer stage then added on by the company making the amp.
Do you guys build anything for car audio?
Better ? Better than what ? How to improve, may be a 'better' way to describe the subject, although you didn't really touch said subject.
The switching speed of the power switches (trans/mosfet) is the bottleneck of Class D Amps. Since switching gear (PSU, ClassD) is still gaining ground because of it's great efficiency, these power switching devices are still being improved. Note that Class D applies only to the driver and output stage of said devices. The rest (power supply and input stage) are conventional.
One can improve Class D Amplifiers by increasing the PWM base frequency and improving low pass filtering.
4G12 One can only increase the base frequency when the switching devices can cope with those frequencies. Which is basically what I said. We are on the same page.
Low pass filtering is old school, there's no real improvement there to be made. It all comes down to very clean and fast switching.
What is your personal audio set up
I think Nuprime has their own class D design? Thanks Paul!
In another Paul video about Class D there was some talk about improving the output filter. Class D design creates a lot of high freq. noise as it alternates off/on at high frequency. Is that just part of the ICEpower package now and doesnt' require modification?
Any good class-D design addresses the residues from the switching frequency.
from my prospective class d amplifier as any other needs to be more than you need in power in wats out. but driving it with less to make it less distorted is the source of success ;) of course there are considered a clean power to make it less noise. but but... i still think everything digital is losing the quality of something in sound....
i don’t know what it is but it’s there if i compare.
Try a blind test and see if you still think the same.
I think the (near) future of class D amplification belongs to AGD, Atma-Sphere and Mola Mola…
Well built Class A amps are in my experience the most magical sounding, but it's impossible to justify the comparatively small sound gains with the enormous waste of power in our world today.. Class D is truly the future!
You can make a Class-D fully digital and it sounds great. Check it out th-cam.com/video/Vru9ilH5iis/w-d-xo.html
What!? If that amplifier module is linear from rail to rail, then the input stage should be TRIVIAL. An input stage should do Nothing but prep the signal (linearly otherwise you're introducing distortion) for the amplifier stage. There's no 'magic sauce' there. The only thing I can conceive of as an acceptable means of changing the sound, is only if you decided to do some filtering, like a LPF for sub-woofers, or overall 20-20Khz bandpass filters. Also, signal conditioning like XLR difference input op-amp arrangement, or soft clipping/limiter circuitry is also acceptable.
If an input stage changes the phase or magnitude of the original signal, then I call that distortion.
So what possible secret sauce could an input stage do that is 'better' than someone elses? Maybe you change the input impedance, output impedance, or add other 'features', but don't touch the original sound and change it in any way. As Gene says, it shouldn't be a tone control.
My $0.02.
So, in short, the sound quality of the system is depend on the pre-amp input and the quality of the speakers, right? The class D amp is not that important other than provide the power to the speakers, right?
Oh the hyperbole! Class A, A/B and D are all the worst sounding and best sounding. It could be said that in fact, there is no difference in sound between A, A/B and D. The difference comes from the build and components used. ICE circuits or IC chips are going to sound sterile almost lifeless. Traditional circuitry can sound musical, live, etc. Then there is the mix of both which can give engineers headaches until they get them working how they want. Classes of amps are all about heat and heat is the enemy as many have stated all ready. The rhetoric we hear today from "audiophiles" (again) is that class D amps are no good and the reason in their minds is because....wait for it......class D amps don't cost as much. Yup, price tag price tag price tag. Price does not always denote quality. I've seen shitty $50,000 amps (Bob Carver springs to mind for example). In reality class A, A/B, D amps can sound great or bad, it is all in the build and how the pitfalls for each are dealt with. Simple as that. Gear is good or bad and set up properly or not, that's it. People should be allowed to enjoy what they have if it is working for them without worry about marketing hype and audiophile blabber. Committed companies such as PS Audio for example are going to make good gear, class A, A./B, D or otherwise and will and should advise the customer of the pluses and minuses of whatever it is.
I can only agree.
Badly designed stuff sounds worse than great designs.
Something is wrong when you, as a seller, buyer, reviewer cares about the inside of the box.
The only valid question may be
"Is this thing worth the money to me?"
As I see it, the problem is that some have heard bad sounding amp's and therefore the technology inside the amp is the reason.
May it be class-D , negative feedback or whatever.
Eric Elliott: Paul is refering to the ICE module by B&O NOT an IC.
You cannot say IC's sound lifeless either, depends where you put them in the circuit and what they used for; if you were talking in general terms I will let you off)
Ah yes, I was talking in general terms indeed. It is like DAC chips, everyone says this brand or that brand is better or worse Burr brown better than Wolfsen, Wolfsen better than ESS, etc. They are really all the same in my experience having owned products with all of them. Their "performance" depends on how they are implemented. I have had terrible performance from Burr-Brown dacs and great performance from them for example.
Eric Elliott: I agree somewhat, we seem to have sensible manufactures at the medium pricepoint making real improvements; but when you look at SOME high end stuff they are actually inferior circuits to a medium outfit; but use shiny well machined cases to 'justify' their price wrapped up in jargon tailer fitted to the audiophile. If I was crazy enough to spend 10k or so on a DAC the least I would do is take it apart before ordering one, of for those without electronics knowledge get someone with knowledge to asses the design.
Too many snake oil salesmen at the upper end of the market. From what I have seen Pauls company isnt one of these, but you could accuse a couple of their products they sell to be nearing the realms of pseudo science.
I agree Suzy. I was an independent audio journalist for almost 4 years and was independent for that very reason. My mission was to help folks new to the hobby or not navigate through the murky shark waters of audio to find the islands of truth and educate themselves to make informed decisions. Always focus on real science. Yes, the high-end realm is full of tricksters who use pseudoscience and when you present real science they get upset. I have countered a few of them in person and was able to show them and they still told me I was wrong.
PS Audio is one of the relatively honest audio companies though. I think they have a few things figured out. They also have no problem recommending other brands, so that says a lot right there. Yes, one or two of their products leave one scratching their head a bit, but other offerings they have are well made and priced pretty near appropriately. Just because something cost a lot of money doesn't mean it is snake oil, but if it comes down to using inferior circuits and such or trumpeting nothing but the badge and jewels and ego stroking, you can bet it is likely to be snake oil or an illusion. In other words, mid-fi in a high-end case with somebodies name on it.
Anyway, I know who the "snake oil" or rather the gouger guys are and who are not, sadly there is more who are than not.
You are correct about some of the mid-fi stuff out there being very close to upper scale in quality and build. Marantz is a great example. A number of what some consider to be their mid-fi line is made with the parts they use for their reference line and it shows in performance.
Of course due to stupid tariffs the price of everything is rocketing up, so parts to build the gear are getting more expensive.
Ice Power......A B&0 invention.
Auxiliary power to filters and directly 240/120 power, no need for
Transformers.
Pretty smart.....
Very good answer, thanks Paul!
How to make Ferraris drive faster like our old Buick.
Buick?
Het is buik en niet buick.
Gekke Amerikanen ook altijd he 😂
Here is a good answer with lot's of insight to the question "How to make good class-D amplifier."
from Bruno:
th-cam.com/video/0vsOugSsANs/w-d-xo.html
Too bad Hostess no longer makes chips. they were great.
Hey bro, if a class d amp is 4k and a class A-B amp is 4 k, what is the difference
the temperature is cooler on the class D and it is probably lighter. Class D and AB are on par as, A badly designed AB amp is just as horrible as a badly designed Class D. Being a DJ for 35 years means my hearing is not great but i can still hear well enough to know when the sound is distorted or hissing or hum from a amp at rest . I used to be really worried about quality when i was a teenager but learnt the money wasted for a small change in the absolute best sound quality would be better spent om more or louder gear because when people are drunk they cant tell the difference. Saying that I dont like cheap gear. I like gear that works all day and night and works reliably for years. in the audiophile space my oldschool NAD AB amp does what i need it to do.
The Class D won't do subsonic bass
i am running two hypex fa253 amps with build-in dsp into two tops (kef ls50) plus two subwoofers (sb acoustics 10inch) and i am very happy about it.
I make my living with class D amps. the fact i can have 2kw self powered loudspeakers is amazing.
@Dirk Knight If you think 20w is enough for the full system, I would say you don't have any bass in your system.
@Dirk Knight -- More power means more clarity at normal listening volume because brief orchestral or big band peaks won't push the amp into distortion. Moreover, modern speakers are trending smaller and therefore tend to be of relatively low sensitivity, making it impossible to produce realistically solid bass with even the best 20WPC amp. I found this out four decades ago, when I replaced my 25WPC Sansui integrated amp with a 50WPC Kenwood -- and that was with relatively sensitive speakers that had credible bass response well down into the 30s!
@Dirk Knight -- In my experience, amp clipping is very real with low power units. In fact, that 25WPC Sansui clipped hard enough to burn out a tweeter -- this was so common with that particular speaker that the manufacturer offered a "tweeter saver" gadget for folks who insisted on sticking with their low-power amps at room-filling (but still "normal") listening levels. With the 50WPC amp, no clipping, no tweeter damage, and much more solid bass. I rest my case -- high amp power is desirable for any number of reasons, even at volumes far short of potentially damaging ones hearing.
@Dirk Knight -- I'm getting palpable sub-40 Hz bass from a pair of 6.5" drivers in a suitably configured enclosure that fits under my desk. Your presumptions on that account are obsolete and have been ever since the industry learned how to effectively apply the Thiele-Small equations. You seemed to miss the part where there was no HF clipping -- your 20 kHz test tone mention is a straw man, since the tweeter in question was high- passed at a far lower frequency and the clipping could have occurred at any point above that -- and therefore no tweeter damage with the higher powered amp, with no "tweeter protection" other than what was in the crossover circuit.
@Dirk Knight -- When there's power to spare, efficiency is a non-issue as long as the driver is up to the job. As I previously mentioned, your presumptions are obsolete. 6+ decades ago, Edgar Vilchur designed a bookshelf-sized subwoofer known as the AR-1W that had bass response that put massive beasts like Altec's Voice Of The Theatre, Klipsch's corner horns, and Bozak's big infinite baffle designs to shame -- but it was woefully inefficient and the amps of that era couldn't drive it to room-filling volume without going into clipping, so it was relegated to relatively undemanding applications in the living rooms of low-volume listeners where it beefed up the bass response of fancy electrostatic panels.
With the proper implementation of Thiele/Small parameters, modern speaker designers can balance the three key factors of enclosure size, efficiency, and bass extension to suit the application at hand, and the cheap availability of high-power, low-distortion amps makes sacrificing efficiency (to one extent or another) the sensible choice. An example of this approach taken further down the development road is Bruno Putzys's Kii Three system, which integrates drivers, room-compensating DSP-based EQ capability, and multiple low-distortion Class D amplifiers into enclosures considerably smaller than an AR-1W's -- and it delivers bass all the way down past the limits of human hearing at volumes way higher than your "normal." For exceptionally large rooms and/or even higher volume, Kii offers a extra powered woofer module for that.
BTW, I agree with you that typical modern small bookshelf speakers -- like Andrew Jones' designs for Pioneer and Elac -- don't need a 500WPC amp. That said, they really can't make do with a 20WPC amp either, because they sacrifice efficiency for bass extension -- if you want an orchestra to sound like an orchestra through these little wonders, you'll want a 60+WPC amp as a minimum, preferably augmented by a subwoofer to provide that sub-50Hz fraction of an octave that even a well-designed speaker of such modest dimensions can't manage.
Wonderful. I don't use mosfet (mosfat) as they are slow (fat). Use moslean. They are faster.
In my class d design, i've used complementary pairs. (twins but different gender)
If you're building a self oscillating class d, avoid unnecessary capacitance in the loop.
Keep all components close as possible. And coil many a filter by hand. A particular filter is only good for a particular speaker.
In fact if you need to change speaker, coil again the filter until you are realy satisfied with the results.
Boy I sure had fun with class d.
If your class d is working properly, you could hear the news casters door creak when someone enters the studio.
Excellent video.
It's important to note that a good class D amp is often times more revealing than other amps. And when a component is more revealing it is indicriminate about what it reveals, whether it be music or distortion. So without superior line conditioning a good class D amp can easily sound less musical.
But here's something even most class D amp mfg'ers don't know. Though not digital, Class D stereo amps being high-speed switching amps will induce a digital-like bi-directional noise. Since this noise is bi-directional this distortive noise from one channel will induce that noise into the other channel at the shared AC inlet and vice versa.
It gets even worse if we're talking a Class D stereo integrated amp. Besides the high-speed switching amp noise shared between the 2 channels at the AC inlet, the active linestage pre-amp section must borrow AC power from one of the 2-channels. Since both channels are already sharing their bi-directional noise with each other, and since the pre-section section must borrow AC from one of the channels then it too is blasted with this high-speed switching amp noise from both channels. Thus making a bad situation even worse.
Never buy a 2-channel integrated Class D amp for this reason. And if the stereo Class D amp has a single AC inlet, don't buy it.
If you do buy Class D amps, buy the mono-block versions with separate AC inlets and attach a superior passive, dedicated, bi-directional filtering line conditioner (they are rare) to each amp. Assuming the amps (and line conditioners are of superior design and performance, the Class D amps should now compete and quite possibly exceed the musicality of many competing amps.
.
I should also note that since this digital-like bi-directional noise is indeed bi-directional, without superior line conditioners that also handle bi-directional filtering, this digital-like noise will also go out into the wall outlet and induce its distortions on any other component sharing the same circuit. Some say such bi-directional noises will go all the way back to the service panel and into other circuits.
Superior line conditioners (that actually work) are a foundational requirement to any playback system. But even more so to those incorporating Class D amps and/or digital sources.
Since many/most know little to nothing about superior line conditioners, I suspect this is one reason so many poo-poo Class D amps.
Then again, if you're not using superior line conditioners on every component already regardless of component type, I guess none of this really matters much anyway.
How about the DC 2-channels integrated Class D amp? Will it share the bi-directional noise like the AC amp?
Thanks,
@@lanphanh Don't know. But if the 2-channels share the same AC inlet, you're gonna have minor issues. If the pre-amp section is borrowing power from one of the 2 channels, you're gonna have major issues. I love some Class D ams but I'll only buy the Class D monoblock versions and I always always always connect every component to superior passive, dedicated, and bi-directional filtering line conditioners. Did I say always?
Making a class D amp sound better was the question !
I thought he explained. The "sauce" is in the input stage, with MOSFETs and regulated power supply to that stage. Although he didn't mention the other end, I imagine the filter at the end, some kind of coil and capacitor, the type and quality, would make a difference.
Have you tried it
I happen to notice that many class d amps really don't have a box big enough to have a oversized power supply. So, many could be current starved. My first tested class d has a large box power supply bought separately that included a constant on fan. It can get hot when pushing the amp. It's like many audio designs out there that have power supplies just big enough. I think everyone should have a class d amp in addition to the other types so the advantage can be heard.
Manard H, I agree that a lot of the audio equipment manufacturers don’t provide enough current in their power supplies. Years ago there was a big movement within the audio DIY community called POOGE; this was optimizing store-bought equipment to take it to a whole new level. A lot of this was power supply upgrades.
They don't need a large box. Switching power supplies are efficient an compact. If there isn't enough power, it means they screwed up in their design
Nothing wrong with my Pioneer receiver and that is class D. Also B&O use ICE class D amps in their BEO LAB 90's so it can't be that bad.
as long as it's not a 5.1 receiver that cuts the low frequencies of the front speakers and leave them only for the subwoofer output .... those are god awful! VSX-531 comes to mind...
Umm that is adjustable with something called a crossover
i am talking about a relatively cheap end pioneer 5.1 receiver that cuts those frequencies internally... why and where are you going to connect a crossover to it?
@@matsudakodo those channels arent built to deliver that kind of power. Might work on a small 5 watt speaker but anything bigger is pointless.
If a good class “D” amp was designed right in the first place, no “band” aids would be needed to try to make it sound better!!! Bottom line,.. you get what you pay for.
Good sir
So If you have a class D power amp and a passive preamp, you should adjust your gain on the class D amp to be as low as possible to reach your preferred listening volume with the pre-amp potentiometer at 50% volume?
Hi - I have done just that! I have nc400's. the gain on these amps isn't huge so they actually don't come across as being a powerhouse amp anyway - probably similar to my 50watt naim in terms of 'O clock' un-attenuated. I wired in the attenuators to my interconnect to keep things flexible (kimber also do attenuated leads)the beauty imo of hypex in particular for passive pre's is the high Zin which makes matching easy. I am sure they would inevitably be better with a pre amp, and with that you can add the 'sauce' - it makes for a logical upgrade path and you can live with it a while first.
Thanks for the reply! Very nice setup you have!
TI3116D2?
I think that eventually Class D will be better than tube Class A. Its the cancellation of crossover distortion (good) and the elimination of distortion products caused by the high switching frequencies and the delicate output filtering handling (work still needed).
MOSFET class A is already better than tube class A, not that any audiophile will believe it; since they are woo'd by the hypnotic glow of the tube the rest of the sheep are following.
Suzy Siviter A good example of MOSFET use in an output stage is Vinnie Rossi’s Lio amp.
David Tomsett: Yes they are used in many amplifier designs, I am am particularly facinated by ground breaking speaker designs such as the MBL Radialstrahler and the rotary sub, I am going to try and raise funding for an idea I have to combine the two. It does seem to me the technological improves in amplifiers and sources are reaching saturation point; but the current loudspeaker technology could be improved beyond anything available at the moment.
Suzy Siviter PS Audio’s new speaker range is going to feature servo controlled bass units so that should be interesting . Problem with speakers is how they react with your room.
Bass sources need to be moved around the room to find their best placement. No bass woofer in a tower speaker will ever be able to perform at its potential in a room, no matter if you're buying $100 or $100,000 speakers. Proper subwoofer placement is the only way to get truly great bass.
Hasn't this one got everyone to come out of the woodwork..!
Class AB mosfets with floating cross overs are the best method .. Claas D hates over reactive loads .. that's why this class of amplifier will always end up driving single speaker sub woofers
Hi Sir I am Satyabrata Senapati from India.I want to make a professional career in audio.So can you give me any suggestions about career in audio equipments.
I do experiments with wireless audio,audio signal processing & also designing good amplifier.
And also have a strong background in all class of amplifiers.
Previously I was working as a Embedded Software Engineer.
Thanks .I mean is there any openings related to DSP,amplifier design.
Thanks for the reply.
Build your own Hypex monos and find out what all the hype (!) is about :
th-cam.com/video/NMm4GsUDyLI/w-d-xo.html
I've gotta say - purely on the basis of Ron's video - this would have to be one of the easiest builds I've ever seen. Compare that to Tyll Herstens' Crack build and you'll soon realise how little soldering you need to do for this kit.
Instead of the icepower,i am about to buy a couple of those 20 dollar class D ebay chinese modules; i have a free, broken,half dismantled, ex-professional amp from late 80s, with a 870 VA transformer and clean plus 65 V and minus 65 V p.s.; the amp modules have 4 2N3773 each, good for about 250 Watts, but the protection circuits on both do not feed the relay coil,on both modules,and i gave up already,all semiconductors are good,replaced 3 or 4 transistors, it may be caps, too many to remove and measure, tired of it,too old,even resistors were,and are,rusted where the small steel,go figure, cap meets the resistive element;
I have a nice Rotel (stereo) with beefed up heatsinks, and i have another amp,some small brand, small series,mono heavy amp(over 50 pounds) with 16 output transistors,that i repaired, and plus and minus 75VDC rails, actually with one led for each, on the front panel;
I do not like stereo,neve did since the 70s , i find it strange to hear the vocals coming at me from the left and right,Jim Morrison only had *ONE* set of vocal cords!! So, my home made 2 woofer, 15 inch , 5 ft tall, (also have 2 old ,but like new, 12 inchers Cerwin Vega that live next to each other,tied up together);
I like to listen to The Doors,Mettalica, Dylan, Pavarotti, The Phantom of the Opera, etc etc ( just kidding,i listen to A LOT of stuff, thru youtube,) and i need it to be like they are there ;
So,the question is, will i have to rip the 20 dollar class D Chin Chao modules off and throw them out in the end,or no? The alternative is to buy 2 class AB modules for 40 dollars each, with 8 outputs each; Thanks.
Class A-B is not 50% efficient, more around the 70% mark, small edit worth mentioning.
? so, was the question answered for us, consumers ?
Buy B&O! 🤪🤪🤪
Buy Hypex!
I can be honest. I have a 2k class a Amp and a cheap class d.... The class d sounds so much better😅
What brand and model class d amp?
@@billschnaars9852 it's a simple tda8950th
I am sticking with class A/B.
Why spoil a brilliant pre-amplified analogue signal by using it to modulate a high frequency square (or is it triangular,yuk! ) and then apply L/C filters to recover the original audio?
For purity and fidelity,I say class A or A/B is best.
I am not persuaded by the fact that class A/B is only 50% efficient as against Class D at 90%.
Class D has a use where more power is needed from lower supply voltages and less heat is generated,but that is about it unless I have missed something.
This applies only if you are using all analogue sources.
If you listen to any digital sources, they're sampled at a specific frequency, either at redbook cd 44.1kHz at 16bit resolution, or at higher frequency and / or bit depth.
I believe the ICE modules use PWM at 384kHz, which is more than enough bandwidth to reproduce clean sound, while filtering the high frequency noise the powersupply and other circuitry might generate.
It may not be the 2.8MHz 1 bit bandwidth of DSD, but, it should be enough for audable sound.
Yes,and it is interesting how PS Audio and other manufacturers continue to produce and extol the virtues of their 100% analogue pre-amps.
@@georgebliss964 not at all, what is interesting though, is why some would still use a 1950's NOS vacuum tube as the preamp and even amllifier stages, when they measure to have more distortion and microphonic influence when compared to either transistor based class A , A/B and even class D amps.
To each their own, I'd say. I'm happy powering my B&W N802's via a Rotel RB-1092 which employs 2 500w ICEpower modules, modded by Rotel.
I have seen class AB amplifiers that are 70-75 percent which uses a switch mode power supply and really complex RLC circuits to completely eliminate the switching noise prior to the class AB amplifier circuitry. A variable bias solid state amplifier where it controls the transistor bias voltage on the flying instead of modulating a high frequency triangle wave, is a better way to do it in my opinion. So it uses an analog delay, a feedback loop, a microprocessor that controls how much voltage is supplied to mosfets and mosfet drivers in the class AB amplifier. So it's a DC voltage that matches the peak amplitude of the pre-amplified audio signal so the higher the peaks the higher the voltage, the lower the peaks the lower voltage. So if the pre-amped signal peak voltage is 4.5 volts, 30 volts is supplied to the output transistors and if the pre-amped signal voltage is 0.75 volts, 5 volts is supplied to the output transistors and vice versa.
Make them from tubes?
j k Seems like a valid option. But NO ! Class D is all about efficiency. Tubes most certainly are not.
Which still leaves the impossibility to switch a tube fully on or off, like you can a mosfet.
@@Tubetinkerer It makes me wonder if there might be another way to approach the switchiig function. I remember when RCA implemented SCRs to accomplish the sweep circuit in the old XL100 line of television sets. At the time there was no thought of using such a thing for audio or for faster fundamentals than 15,734Khz. Maybe we should take a second look at SCRs and their possible development potential since they are inherently switches, more so that mosfets or IGBTs. If anyone has experience in this endeavor I would love to hear about it.
InsideOfMyOwnMind To be fair, I had to check up on SCR's. But to my understanding these are only suitable for AC. Once gated they remain open until the voltage on the gate is turned off and the voltage across them reverses.
Since class D amps work of DC, this is not going to fly. Once gated, they'll remain open until the power is switched off.
Anyway, when I was repairing my classD subwoofer amp, I was kind of forced to delve in to the whole class D thing. That's when I found, that while of the demand for fast and clean switching devices is so great, that there is a huge effort being made to improve on said devices.
Tubetinkerer .... Who cares about effecincy if it sounds better. I'm sure I could switch a single ended triode into class d output filter
j k How are you going to accomplish classD with a single ended triode ? You think you'll get 100 watts out ? But don't let me stop from trying.
Start by throwing them out the window.
I find a lot of class D have a permanent low level hiss and badly perform with low volume sound - kind of puts me off. Efficiency, great with modern compressed sound and loud seems to be what it's all about - me thinks it suits the modern world ;)
hypex ncore = zero hiss!
Not sure what your talking about? I have a hypex ncore amp and a nad m51 dac which is also a class A preamp with lossless digital volume control. It doesn't alter any of the digital signal until down below 44dB and it sounds amazing! Zero hiss, absolutely nothing!
We're talking Apples and Pears here. I assure you at a component level (integrated circuits, discrete designs and boards containing them), the problems I describe do occur with most devices. Hiss due to inadequate output filtering and bad board design, and low volume problems due to the PWM not being of high enough resolution to process minuscule changes properly. Class A or AB (set up properly), represents much better quality sound - for your buck. In my opinion.
@@mickybee3247 Class D, when designed properly (hypex ncore!) Is probably superior performance for the $$. You must be comparing crappy class D...
@@MrDingaling007 Yeah cheap class D modules like the TPA3250 sound really good. Most folks that rag on class D have out of date assumptions or a bias. They're very good these days.
I love class d cause i don't know how class a sounds like i never had those high end audio systems
Professional sound reinforcement speaker manufacturers EV/JBL/Meyer/etc have gone 90% Class D power amplifier modules built into powered speakers & subs. This overwhelming trend is 100% due to the elimination of very expensive seperate power amplifier, much lower weight for interior mounting and CONVENIENCE! This trend had nothing to sound quality or improving sound quality through new amplification technology. In fact, this trend has had quite negative effects on sound quality sacrificing it for cost & convenience. I've been a professional sound engineer for 30 years. Class D power sounds like plastic relative to bigger-heavier Class AB & Mosfet sound reinfircement amplifiers with big heavy transformers, man-sized caps, etc. The Class D stuff sounds harsh throught the entire frequency spectrum and do not priduce big, round, full tight, bass like the big heavy duty Class AB & Mosfett amps do. The harder you drive Class D toward its limits the worse/more harsh it sounds. It is the opposite with Class AB & Mosfet. The worst thing about Class D is that it sounds artiificial not organic. Class D if sounds like a charicature of Class AB & Mosfet, or like a fax machine version of an original document.
The Class D vs Class A/AB/Mosfet/tube thing is exactly like the 320kps mp3 (compressed/90% information thrown away) vs CD/.wav (10X the information/file size/resoultion) arguement. If you can't hear a distinct difference in sound quality between CD vs mp3... or Class A/AB/Mosfet vs Class D, then you are in the wrong hobby or business.
There is an exception; subwoofers and the like; since the ear is much less sensitive to low frequency distortion.
Bang & Olufsen
Nothing! All Class-D are essentially the same. I find it quite pathetic that companies are selling Class D modules that cost a cpl of dollars for THOUSANDS by just putting them in a nice box! I personally do NOT buy any "high end" Class-D product, as I know for sure it's 80% snake oil for the premium price charged... Class D works GREAT for sub woofer, low end power, but they SUCK at higher frequencies and are simply mediocre. While it takes effort, better parts, engineering and a bit of Art to make a great Class A/B, Class D is simply re-packaging ICE or Hypex chips... a bit of a scam. If one wants a Class-D amp, buy a mid-level product made by major audio manufacturers as you know they will use the exact same modules, but charge you a lot less!
That's not true and easily tested. Also, Hpex Amps are $450-$500 each, so $1000 for just a stereo set.
Depends on the design. IMO amplifier design is basically finished. It's just a matter of what distortion artifacts you want that's listenable etc There's numerous good class A, A/B and D designs that have distortion figures that are basically inaudible. It's just a matter of pricing and power design limits
@@joshfoss7407 That's good stuff. I wish I had a bunch of those things, like 32 of them :)
I notiest class A amps sound richer & finer than class D .
Class D sounds more edgy , I guess class D is more suited for todays comprest mix recordings
So, engineers don't do anything to make Class D sound better. Secret sauce? FETs? Nice try bozo. Two hints - Class D distorts like crazy at specified max power - don't drive them past about 30%. (Read the spec sheets.) They mostly have (too) high impedance front ends - I use resistor (100-200 ohms) to damp. Also it's probably good to reduce power supply voltage if you can - this should increase (digital) resolution. 7.21 on this - more like "BS Audio"
You lost me!
He did not answer the question because it is Top Secret!
Simon Warner 😎 it is so secret that noone knows how to make it "better".... ClassD is black magic in a black box, designed by men in black, controlled by Black Ops. True story ! 😊
ROFL!!!
I don't know how he lost you. He didn't even really say anything. This seems to be par for the course though. He chooses questions he has no real intention of answering, then beats around the bush. I could understand this, if someone else were asking the questions. But he has a choice of which questions he's answering. Why he doesn't choose the ones he can answer, is beyond me. Many times, he does choose ones he'll answer. But why even bother with the ones like this. That he knows he's not going to answer. Makes no sense to me at all.
HH Scott Exactly. Basically what he's saying "We don't know what we are talking about, you don't know what we are talking about! We just make great stuff at a great price. Therefore buy PS Audio"
No matter how you try to improve it cheap shit is still shit
Why bother?