Why aren't class D amplifier better liked?

Why aren't class D amplifier better liked?

Class D amplifiers have been around for many decades yet they haven’t gotten much of a following in the high-end community. In fact, they are sometimes downright hated. Why is that? Have a question for Paul? Ask it by going to http://www.psaudio.com/ask-paul/

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50 Comments

  1. DonR. on August 11, 2020 at 8:38 pm

    I own a Pioneer Elite SC-07 with the first generation B&O Icepower amplifier in it, it is clean, dynamic, detailed and very musical. I really like Class AB amplifiers mainly for their warmth and musicality but I’ve recently come to favor modern class D.It uses less energy, waste less energy, run cooler and the ICEpower amps are capable of really low distortion while retaining neutrality and musicality. I hope one day to afford one of your BHK amps I like tubes and solid-state used in tandem with one another

  2. maxvideodrome on August 11, 2020 at 8:39 pm

    The trees visible in the reflection of your computer monitor speaks to me. I bet you have a great view from your office.

  3. Buff Barnaby on August 11, 2020 at 8:41 pm

    Class D made for license plate rattling rap-cars Audio quality not important.

  4. Matt B on August 11, 2020 at 8:42 pm

    Paul’s explanation here on Class D principle is the best! Listen carefully! No distracting whiteboard scribbling or larger than life voice acting with hand flailing..just a slow meaningful explanation.

  5. NNITRED on August 11, 2020 at 8:44 pm

    Some years ago Powersoft kicked this argument and the manufacturers on the opposing side of it square in the teeth. The same is poised to happen in high end audio market. Makers fear their huge investments in ancient technology, giant transformers and air conditioner sized chassis die off like dinosaurs.

  6. Lance Mathes on August 11, 2020 at 8:45 pm

    Use Class D for subwoofers, Class A/B for bed loudspeakers, and either D or A/B for height Atmos channels. Done.

  7. no momo from New Jersey on August 11, 2020 at 8:45 pm

    Because they remind me of Behringer cheap garbage junk. Mostly found in solid state amps.

  8. Gunter Flunder on August 11, 2020 at 8:46 pm

    I don’t really see the problem with pulse width modulation audio power amplification. If the carrier frequency is high enough, there is no problem with a simple LC filtering. I have used 500 kHz pulse frequency and a voltage controlled monoflop modulator (based on two NE555) instead of a triangle comparator modulator. My amplifier sounds fine and it has an outstanding good linearity.

    I have also tried delta sigma modulation by use of a voltage controlled charge current source and a simple astable NE555 multivibrator. It works also with outstanding good linearity. Especially low level signals benefit because of the very high frequency (up to 1 MHz) of delta sigma modulation at these levels.

  9. Gunter Flunder on August 11, 2020 at 8:47 pm

    You mentioned, that your analog input stages "shape" the music. Does it mean you MODIFY the analog signal of the source with your input stage circuit design?

  10. Rudofaux on August 11, 2020 at 8:48 pm

    Class D produces a more cleaner sound. Unlike tube & class A that impart impurities such as hiss, distortion, & clipping.

  11. Mike Hydropneumatic on August 11, 2020 at 8:49 pm

    In another video the filter section is simple, now it is complicated.

    Class A is pretty simple with tubes, not efficient but cheaper and better sounding.

  12. Cavemanrod FPV on August 11, 2020 at 8:51 pm

    I bought a $30 class-d amp board off Amazon. It blows away my 3 and 400 dollar onkyo and Yamaha, probably class-a/b amps. No kidding. I can’t believe this little board sounds so clean and loud and has an awesome soundstage Right now, class-d is the best bang for the buck by far for 99% of people. When the tech matures a little more in a few years, it will definitely be the best tech for all audio. Of course, there will be those that always think the technology from their teenage years in the 60’s is the best, but eventually those people will die.

  13. LeeseMedia on August 11, 2020 at 8:55 pm

    Realised I left my mackie p.a. speaker on for a few weeks. No music, mixer turned off.. it’s class D. Was it using a lot of energy ? Hope not.

  14. George Ross on August 11, 2020 at 8:55 pm

    Thoughtfully explained to a neophite. Thank You

  15. HighCurrent11 on August 11, 2020 at 8:58 pm

    How is the reliability of class D? I’m tired of over-heating with my class A- A/B…

  16. CA. Bohol on August 11, 2020 at 8:58 pm

    Nice

  17. Al Rawandi on August 11, 2020 at 8:59 pm

    Paul is a very knowledgeable person on this topic. Problem is he talks like he’s lecturing a group of electronics engineers.
    I’m sorry, but engineers don’t usually google those things because they know them already, and the entry level music hobbyist is learning absolutely nothing from his videos.
    like 98% of youtubers don’t even know what impedance is. Id like to know which audience is Paul addressing to really, because he keeps losing me after the 2nd minute of every video he makes, and I’m coming across much simpler explanations on other channels. Not trolling or anything, just being straightforward here.
    I respect him really for sharing his vast knowledge, I just don’t think he was meant to be a teacher. Usually these sorts of topics, unless supported by a real demo on a real amplifier, will only add more confusion to the listener and rarely teach anything.
    Sincerely,

  18. blackened 1 on August 11, 2020 at 9:00 pm

    Switching power supplies and switching power amps don’t belong in audio. Let the computer industry have switching supplies. Class d will never have the headroom or reserve power that a good class AB will have.

  19. junehi03 on August 11, 2020 at 9:01 pm

    You always tackle very interesting topics in your videos but unfortunately you always lose me a 1/4 way into every video because I am a beginner and a picture person – your discussion with diagrams on a white board would be very helpful… a teacher without a white board is near impossible for students to learn..

  20. Kyle V on August 11, 2020 at 9:05 pm

    Sound. It’s the way they sound. Have not one I like the midrange of. Listen to any class d. Now go find a McIntosh tube amp. You’ll never get that from class d

  21. profd65 on August 11, 2020 at 9:06 pm

    I had a question that relates to Class D. I’m thinking about buying a Class D solid state guitar amplifier, but I heard that Class D amps lose a lot of their power (more than Class A or A/B amps do) when they drive speakers above 4 ohms, and my speaker happens to be 8 ohms. Is this so? If it is, the high watts the amp manufacturer claims for the amp don’t seem as impressive.

  22. GoldenTV Clan on August 11, 2020 at 9:07 pm

    LOL, I thought you were talking about Class-Delightful

  23. Aditya's Tech Villa on August 11, 2020 at 9:07 pm

    PCM/DSD audio > AVReciever Atmos Decoding > Digital ….wire -transmission along AC/DC power > At speaker box —ClassD amp with DAC & with DIGITAL CROSSOVER & feed back system(Speaker oscillation sensor ) > Analog audio signal > speaker/ Tweeter

    Its true that …its hard for making a RC filter …capacitors dont sound same for all time ….

    Class D …with feed back controll system …based on speaker oscillation ‘sensor voltage ‘

    Mean we use …sensor..that may be ….IR optical sensor ….or quartz sensor ……..which corrects speaker oscillations

    So here….speaker must contain ..a oscillation sensor ….OPTICAL sensors are ..high ACCURATE ….
    ..BUT NOW A DAYS …we still using. ..sub woofer (with quartz sensor )

    Even in feed-back topology. ..i am not sure …CLASS D will be precision perfect …in high frequencies …

    I am unsure…classD may be better …if using optical sensors …anybody may …make ClassD amps …

    That days …each ..speaker must comprise its ..own amplifier …..

    Forget to …say this ….

    Class D works best …with …PCM DACs…(i.e. amplifying Bit level resolution of audio corresponding to DAC bus-width….& without converting to analog line level output )

  24. kay bhee on August 11, 2020 at 9:08 pm

    no damp factor,, no control of spkr or sound… best used for pa… or crowd control

  25. Rick C on August 11, 2020 at 9:08 pm

    I listen to music on my pc mostly. I recently switched from a cheap aliexpress Class D TPA3116 mini amp (with some minor mods to reduce noise), and I "upgraded" to a consumer grade Denon 5.1 surround receiver. I have very good bookshelf speakers (Overnight Sensation). Im a little disappointed with the result, in fact it sounds a bit "brighter" but not in a good way, seems harsh. I’m not sure if I had just gotten used to the class D amp’s sound or if it really did sound better to me. I always have and still believe that speaker selection makes a MUCH bigger difference than amplifier selection when trying to improve sound quality.

  26. Lynn Donovan on August 11, 2020 at 9:10 pm

    Maybe the problem is that we as humans have a "time tape measure" going on, and the on/off of the Class D amp is another one, and those two waves going together result in an uncomfortable harmonic, sort of like playing a C and a B together on a piano. Class D amps remind me of the first Bogen pa we had in the 70’s, you know, the "Kmart will be closing in 15 minutes" kind. Like you took ones of those amps and removed all the noise and hum but the basic tone was the same.

  27. kay bhee on August 11, 2020 at 9:10 pm

    went to hear a dozen bass gtr amps… all sound too similar.. class d,,, duhhh

  28. Abraham Ortiz on August 11, 2020 at 9:10 pm

    Class D will be high end if they find a way to make it cost high end

  29. Glenn Watkins on August 11, 2020 at 9:11 pm

    I would LOVE to see a blind test between a class AB (like an Emotiva XPA-DR2) and a class D (like a Crown XLS 2502) power amplifier.

  30. Silver Wang on August 11, 2020 at 9:13 pm

    I’ve never had any problems with Class D Amps, I still use an Alpine amplifier 14 years on.

  31. pdx r13 on August 11, 2020 at 9:14 pm

    If you have to move your pa to a stage regularly, you will love class-D amps. When you need 1000W and you only have 15A on stage, love class-D. 25W at home for horns? Class-A, baby. Switch off when done.

  32. Aikon Latigid on August 11, 2020 at 9:14 pm

    As technician, I thought that today’s class d are more "hi fi" than class ab or even class a, why? Becoz class a & ab had too many parameter that need to be manually tuned: bias, feedback, null offset, gain, etc, & we need xpnsve tool for tuning. Meanwhile class d is more digital like, no coloration, no wild oscillation, just put them on the right place, they sound well..

  33. Toad Stool on August 11, 2020 at 9:16 pm

    Class D amps, though not digital, due to its high-speed power switching module will induce a bi-directional digital-like hash or noise. Superior forms of line filtering / conditioning with bi-directional filtering capabilities either minimizes or negates this problem. The problem being that this bi-directional digital-like noise goes back out the AC and then impacts other components like a little hash or harsh sounding cancer primarily from the other components inpacted by this digital-like noise. A stereo chassic Class D amp with a single AC inlet guarantees that this digital-like noise will be shared between both L & R channels. An integrated Class D amp is far worse than a stereo Class D amp since the active line-stage section of the int. amp must borrow AC power from one of the channels. Since both channels are already sharing this bi-directional noise, the active line-stage is now getting a double-dose of this same noise. Not good. What’s even worse about an int. Class D amp is that this double-dose of digital-like noise is then amplified as it goes through the active gain stage. Stereo Class D amp with separate AC inlets or better yet, mono block Class D amps are the only way to go and even then it’s best to attach dedicated bi-directional line conditioners to them. Under these conditions I reckon a superior Class D designed amp can easily compete or exceed many a superior designed Class A or A/B amp.

  34. SAINT 65 on August 11, 2020 at 9:18 pm

    Well stated; agree from personal experience.
    900 watts of Class D in vehicle via Kenwood’s eXcelon Reference XR401-4 amp & 2 eXcelon Standard X502-1 mono amps.

  35. PhuckHue2 on August 11, 2020 at 9:19 pm

    Tried Class D. sounded like shit

  36. popitn2nd on August 11, 2020 at 9:20 pm

    Is the TC electronic RH750 amp a good Class D amp? But this is so expensive amp. I thought Class D amp supposed to be Cheap!

  37. Delkomo on August 11, 2020 at 9:20 pm

    So, if I understand correctly, one should be extra cautious when going for a class D amplifier, because the chances of being finally disappointed with their sound are much higher than in the case of class AB amps.

  38. Mark Philpot on August 11, 2020 at 9:21 pm

    I don’t understand the design nor am I impressed with the sound of any class d amp I have ever heard. As far as I am concerned, they have one purpose in audio and that is in subwoofer amps. Not even a fan in that application, but it is the only one that has any promise for this technology. I am sure to get hate mail for my opinion and I am sure that there are others that differ from mine. Oh well, opinions vary! Class A or A/B for me in matters of audio amplification! Let the haters hate and let the hating begin!

  39. Kris Hollerday on August 11, 2020 at 9:21 pm

    Thanks for explaining this so clearly Paul. Class D amps are the way of the future, and will keep improving.

  40. tremot on August 11, 2020 at 9:25 pm

    I’ve got Class D amplifiers in my integrated amp and studio monitors. ICE ICE baby!

  41. Bob H on August 11, 2020 at 9:26 pm

    Thank you for verifying that Class D is not digital! By definition, digital involves "bit word" (I.e. 4 bit, 8 bit, etc.). Class D is pulse width system with pulse widths varying in analog way.

  42. Charlie Angkor on August 11, 2020 at 9:27 pm

    Class D samples the signal at the point of the edge. Nyquist theorem must be satisfied otherwise sound aliasing will be heard. But this is even worse than Nyquist because Nyquist theory is for uniform sampling. Here the sampling point varies with the signal content.

  43. Francesco Scinico on August 11, 2020 at 9:27 pm

    Can you be my grandpa? 🙂

  44. Jazz Haze on August 11, 2020 at 9:29 pm

    Sounded a lot like an ad for your products…. Am I the only one that noticed?

  45. Thad ward on August 11, 2020 at 9:30 pm

    You were doing so well explaining class d right up till you said @3:20 "these longer and shorter pulses then have to have there edges taken off", implying that the lc filter somehow rounds every edge off of the carrier signal and recreates the music. The lc filter is just a low pass filter set somewhere below the carrier frequency and above 20k which removes the carrier signal almost completely, leaving the sliced up and amplified copy of your jam behind. No rounding takes place, lol. I would agree that the lc filter can cause some impedance mismatch issues but more important to noise is deadtime/shoot through timing errors, and maybe even more important are quantization/modulation scheme errors. This is where the bulk of the work goes not the humble lc filter.

  46. Toad Stool on August 11, 2020 at 9:30 pm

    Class D amps, though not digital, due to its high-speed power switching module will induce a bi-directional digital-like hash or noise. Superior forms of line filtering / conditioning with bi-directional filtering capabilities either minimizes or negates this problem. The problem being that this bi-directional digital-like noise goes back out the AC and then impacts other components like a little hash or harsh sounding cancer primarily from the other components inpacted by this digital-like noise. A stereo chassic Class D amp with a single AC inlet guarantees that this digital-like noise will be shared between both L & R channels. An integrated Class D amp is far worse than a stereo Class D amp since the active line-stage section of the int. amp must borrow AC power from one of the channels. Since both channels are already sharing this bi-directional noise, the active line-stage is now getting a double-dose of this same noise. Not good. What’s even worse about an int. Class D amp is that this double-dose of digital-like noise is then amplified as it goes through the active gain stage. Stereo Class D amp with separate AC inlets or better yet, mono block Class D amps are the only way to go and even then it’s best to attach dedicated bi-directional line conditioners to them. Under these conditions I reckon a superior Class D designed amp can easily compete or exceed many a superior designed Class A or A/B amp.

  47. panelman64 on August 11, 2020 at 9:30 pm

    I use a Leema Elements integrated amp which is class D……..it’s like Jesus coming in your ears.

  48. mzondi1970 on August 11, 2020 at 9:32 pm

    So what do you use in the Sprout? I’ve been interested in looking at purchasing that one

  49. Anders Forsgren on August 11, 2020 at 9:33 pm

    Ok, perhaps I am set in my ways, and remember the horribly sounding class D too well.
    I take your advice Paul and give them a listen again, and see if that improvement have happened. 🙂

  50. Dave R on August 11, 2020 at 9:35 pm

    My bands use a Yamaha class D and a Yorkville class D powered mixers and they both sound very good, with power to spare to run both mains and monitors (8 ohm speakers). You can literally pick them up with a pinky finger. You can’t beat that for live music compared to breaking your back to move 80 pounds and more mixers and separate power amps.

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