Sounds like the "chopper" is a PFC (Power Factor Correction) boost topology SMPS before the normal voltage transform stage, it essentially (usually) makes a 400V DC stage from 230V AC (in Europe) supply and that can then be switched at higher frequencies with smaller transformer size for a given power for the wanted output voltage stage.
Hi Poul Thanks for your videos, i guess i have seen them all. I understand why only a small tranformator i needed, but why are the filter caps so small on a Smpt compared with a linear PSU? Dosend the Smpt need a 'powerbank' like a linear PSU?
I recently went from a Class D amp to a conventional Class A-B power amp. Upon my first listen to the new conventional amp, I noticed that it had a very clear, unsmeared midrange and lower midrange. I was happy to be back on a conventional amp. Years ago, I built a pair of SWTPC Tiger B power amps... still among the BEST sounding amps that I've ever heard... very warm with a high level of fidelity. Nice video, Paul! Thanks!!
@@jasonkillsformomy I knew this material very well and listened to it on the same set of speakers. The clarity of the class AB amp was emotionally moving compared to that of the class D amp. With the class D amp, music was not nearly as moving as it had been.
@@jimrogers7425 And how did you remove bias, placebo and or other mental states from the test? What was it that was moving. Prostate, bowels or perhaps the cardiovascular system?
@@jasonkillsformomy This was a subjective analysis, but one based on my dissatisfaction with the quality of sound that I'd been experiencing with class D amps. My background is in the recording studio, so I've been exposed over long periods of time to very high quality, high fidelity studio monitors. So I back this opinion with high levels of experience over many years. If you want a scientifically supported study, I'm not even attempting to do this. Thanks for your comments.
@@jimrogers7425 Well at least you admit that the test wasn't scientific. What studio monitors do you use? As you don't use class D then I presume you don't use DSP ether. You probably think that DSP is even more blasphemy. Yamaha NS-10 or Augspurger? Maybe Neumann. But you seem like an old school guy who doesn't like active speakers.
Thanks Paul for your very informative information on Class d amps. I am currently experimenting with a ganfet class d stereo amp. (Peachtree). My speakers are an Electrostatic Kaya by Innersound. I find that the Ganfets are quite impressive but at high listening levels it can not supply the needed current that electrostatics require and begins to poop out. To get the 400w/ch at 8ohms these amps are already bridged. The switching power supply just can’t supply that needed current. The company said the only way I might be able to get more current is to use only 1 channel of the stereo amp and purchase another stereo ganfet and use 1 channel from it. Does that sound to you a reasonable solution? I would like to know could a ganfet amp be modded with a traditional power supply that could supply more current? I know one of the earliest class d amps from John Ulrick of Spectron had large transformer based power supplies. Lastly, have you experimented with ganfets and do you ever plan to manufacture an ganfet amp? Hopefully, you could have some options to purchase with a ganfet amp such as a high current power supply and other options. Thanks if you have time to answer and sorry this is 🙄so long.
It keeps both the shipping weight and the monetary costs overhead factor down. For the companies manufacturing them. ie. Offshore somewhere in some back lane located in Taiwan.
I most cases replacing a "switch mode supply" with a well designed "linear" supply in a class-D Amp will improve the sound. The "switch mode" supplies are just used to keep the weight and the price point down. It's more about marketing than audio quality. Of course Paul did NOT mention why you NEVER see "chopper-switch-mode" power supplies in Class A/A-B amps.
@Douglas Blake We are watching Pauls channel....which talks hifi...not AV. You can't name one hifi manufacturer??? That's about what I expected. I see you willing to reply to many people's comments. That's great, but at least pass on the correct information before you write something
@Douglas Blake Doug...you are diverging. I'll ask again. Name five manufacturers and the models that use a switching power supply in their class AB power amplifier. You are the one that spoke nonsense and now you can't answer the question. And even though I shouldn't have to go down your rabbit hole because you can't answer my direct question and you are diverging, AV manufacturers are still using a very good amount of linear power supplies. You are wrong with that comment also. You're acting as if 80% of Manufacturers are now using a switching power supply in their AV receivers. Wrong again.
@Douglas Blake the Yamaha is w years and the power supply hasn't changed in the newest models - be quite when you have no clue how! The power supply is one of the marketing points for Yamaha Aventage AVRs
Do the output devices on Class D amps exhibit crossover distortion? The solid-state, Class A amps I used to build, employed MOSFET's, in TO-3 packages, operated at 90 C, at 2 Amps of bias Current to achieve, Class A operation, by the designer's topology. AudioAmateur/Old Colony would sell the boards for 25 bucks/channel. I built the linear PS to easily deliver 4 Amps of bias Current, for more power. By building my own linear PS, 800KVA toroidal transformers were 90 bucks/channel, HEXFRED diodes, a couple of bucks a piece, large filter capacitance, from a surplus House, CHEAP, double bypassed those for less Inductance, as per J. Peter Moncreiff's instruction, in His Journals. Heat sinks relatively inexpensive too. I wouldn't pay the price, compared to someone else designing, building, marketing, etc for retail. I'm just too cheap, plus the learning experience is enriching. Yet the difference between operating the amps at 0 Amps bias current and 4 Amps bias current was amazing. Eliminating the amp of crossover distortion from the Transistors was ,"Magical", vis a vis sound quality. Today, my kit built, EL 509 based, Single Ended, Valve OTL I use, is 3% efficient, delivering 7 watts at 16 Ohms, 4 watts at 8 Ohms, so I use Lowthers at 15 Ohms and Raals at 16 Ohms, plus Stax ear speakers. I'm addicted.
@Douglas Blake Thanks for the reply. I've never listened to a Class D, but maybe I will look at some of the kits, where the boards are already stuffed and all that's required is to also purchase the PS and chassis.
@Douglas Blake I've read about the NCORE line from Hypex, situated in Maylasia, although not sure they'll sell to an individual. I'll check out the Aiyima. But as of now, I'm in the middle of a Transcendent Sound," Slider", preamp, which employs zero feedback and the venerable, although now JJ Electronics manufactured 6386 compressor tube for variable gain AND a phono stage is included. I really don't like point to point wiring though. My eyes aren't what they used to be. I appreciate your advice, again thanks.
Back in the mid "70's as a Kenwood Rep, I was travelling with the Kenwood High Speed Clinic. I would go to HiFi stores and set up a test rig with a signal generator sending a 10Khz squarewave into any amp anyone brought in, crank the amp to stated power out into an 8ohm load and measure slew rate and rise time while reviewing the look of the squarewave out on the scope. The Kenwood was lab perfect with a 10Khz squarewave at full power. Very few others even came close! e.g. Yamaha tended to use quasy-complimentary outputs and even a sinewave looked bad! Sony had just come out with switching power supplies in their amps. After 3 in a row literally went up in smoke, I refused to test anymore switching supply amps. Fortunately they had signed wavers and the units were under warranty. I hope the design has come far enough since then! My concern being claims of a tiny class D amp at maybe 500W @ 4ohms from a wall wort supply?
I'm not sure why the industry still toys with the idea of switch mode. It should stick to phone and laptop chargers etc and stay FAR away from audio or RF circuits.
@Douglas Blake i’m a class A fan boy from linear power supply through preamp through amplifier. I build my own from scratch But I will say with these new GaN FETS once they have them dialed in and they perfect them I think we will have some petition where might be difficult to tell the difference between a class A and a class D. And it will be a good thing for conserving power in people who live in hot desert climates and don’t have air conditioning in their room
I'm sorry but all this technical stuff confuses me. I'm not into Hi Fi for the tech I'm in it for the music. Does Class D sound as good as Class A or AB? Seems some think so and others say it doesn't, and then there is the debate about solid-state verses Valves (tubes). Tubes sound better seems to be the prevailing opinion (that's why SS designers always aspire to sound Tube-like). To me if its hot and inefficient but sounds great then that't the way to go. If it can be efficient and lightweight and sound as good then that would be the way to go. From what I understand Class D is getting closer to AB and AB is getting closer to A but if you want the most pleasurable/natural audio sound (and isn't that the goal of High Fidelity Audio) Class A with Tubes seems to be the gold standard at this point in time.
@Douglas Blake Thank you for your response. I agree with you that Class D amplification is good and is useful and the quality of audio reproduction is getting better but if it really sounded as good as Class A or even Class AB why do all the high-end designers (like the Late B. H. King or Nelson Pass) still design Class A or AB and why would PS Audio promote their BHK series as their top-of-the-line amplifiers over their own Class D amplifiers? As I said in my original post for me it's about the sound (and I don't listen to the class D amp in my TV, I run my TV through my outboard DAC and through my Class AB amplifier because it sounds better. Class D is good but isn't as good as A or AB, maybe in another 30 years it might get close.
Tubes and transistors can sound alike - depends upon the circuit design. Tubes, alas, degrade with use - they do not "break-in" and sound better, contrary to what the "golden ear" crowd claims!
@@terryjefferylee6314 Like anything else there are good and bad sounding Class D amps just like good and bad sounding Class A AB. It comes down to being a religious war where newer designs threaten old school thinking and egos. I've owned many SS Class A AB as well as tube amps, and a few Class D amps. Some are excellent while some are over priced for audiophools because higher price equates to better sound. You can see it for yourself in the audio rags. The higher priced gear is always ranked higher. As a business PS Audio is smart for catering to both crowds - old school traditional and open minded adopters of newer tech.
A second reason that Class D amps have small power supplies: They don't waste half of the power supply's output by turning it into heat. A Class AB amp that makes 100 watts into the load will need a roughly 200 watt power supply. A 100 watt Class D amp may only need a 115-120 watt power supply to do the same thing.
Thanks for the explanation,but honestly, I'm more confused now than I was at the outset...lol...with all of the gains we have seen in class D over the last few years, some are saying that class D is the future. Anyone here in the comment section have an opinion on this?
GaN technology is going to change all this, allowing a Class D to sound just as good as Class A It's not cheap, but it's relatively inexpensive for what you're getting
@Douglas Blake and your point in some comment I had to scroll for? I for one like the geek stuff. Paul did not go to the geek side, imo, on this topic. I’m confused in your reply.
Keep switch mode FAR... So VERY far away from my audio. My listening room is segregated to it's own circuit in the house, with it's own db box. You are not allowed to even plug in a phone to charge here. All equipment was home made, so power supplies also have 47nf caps over the diodes (BY229) in the rectifier to assist with cleaning off crap that comes from mains and are translated to the 30 or 50v path. Satan himself invented switch mode psu just to mess with us purists. Switch mode is a terrible solution to a world wide design flaw. Mains should have been 200hz globally. No way to recover from that now, unless you are willing to make all current electronics obsolete and start again.
Sounds like the "chopper" is a PFC (Power Factor Correction) boost topology SMPS before the normal voltage transform stage, it essentially (usually) makes a 400V DC stage from 230V AC (in Europe) supply and that can then be switched at higher frequencies with smaller transformer size for a given power for the wanted output voltage stage.
Thanks , Paul ! I knew much of this , but never heard of a chopper ( other than a Harley-Davidson) .
Very informative, i learned something new.
Thank You!
I am still amazed when I compare the size of my M1200’s against new BHK 600’s.
Both rated at 1200 watts at 4 ohms.
What's amazing is how PS audio had their monster discounting on the Stellar line which shows the margin is astronomical
🤗👍THANKS PAUL…. 🤗AND I USUALLY UNDERSTAND …does this make me one of the chosen few 🤔😁💚💚💚
I have both classes, and although my Class D sounds good, it gives me ear fatigue whereas Class A/B does not.
Hi Poul
Thanks for your videos, i guess i have seen them all.
I understand why only a small tranformator i needed, but why are the filter caps so small on a Smpt compared with a linear PSU? Dosend the Smpt need a 'powerbank' like a linear PSU?
That massive toroid on the shelf! 🤤
I recently went from a Class D amp to a conventional Class A-B power amp. Upon my first listen to the new conventional amp, I noticed that it had a very clear, unsmeared midrange and lower midrange. I was happy to be back on a conventional amp. Years ago, I built a pair of SWTPC Tiger B power amps... still among the BEST sounding amps that I've ever heard... very warm with a high level of fidelity. Nice video, Paul! Thanks!!
You did a double blind ABX test?
@@jasonkillsformomy I knew this material very well and listened to it on the same set of speakers. The clarity of the class AB amp was emotionally moving compared to that of the class D amp. With the class D amp, music was not nearly as moving as it had been.
@@jimrogers7425 And how did you remove bias, placebo and or other mental states from the test? What was it that was moving. Prostate, bowels or perhaps the cardiovascular system?
@@jasonkillsformomy This was a subjective analysis, but one based on my dissatisfaction with the quality of sound that I'd been experiencing with class D amps. My background is in the recording studio, so I've been exposed over long periods of time to very high quality, high fidelity studio monitors. So I back this opinion with high levels of experience over many years. If you want a scientifically supported study, I'm not even attempting to do this. Thanks for your comments.
@@jimrogers7425 Well at least you admit that the test wasn't scientific. What studio monitors do you use? As you don't use class D then I presume you don't use DSP ether. You probably think that DSP is even more blasphemy. Yamaha NS-10 or Augspurger? Maybe Neumann. But you seem like an old school guy who doesn't like active speakers.
I've always wondered that myself so this was eye opening!! I
Thanks Paul for your very informative information on Class d amps. I am currently experimenting with a ganfet class d stereo amp. (Peachtree). My speakers are an Electrostatic Kaya by Innersound. I find that the Ganfets are quite impressive but at high listening levels it can not supply the needed current that electrostatics require and begins to poop out. To get the 400w/ch at 8ohms these amps are already bridged. The switching power supply just can’t supply that needed current. The company said the only way I might be able to get more current is to use only 1 channel of the stereo amp and purchase another stereo ganfet and use 1 channel from it. Does that sound to you a reasonable solution? I would like to know could a ganfet amp be modded with a traditional power supply that could supply more current? I know one of the earliest class d amps from John Ulrick of Spectron had large transformer based power supplies. Lastly, have you experimented with ganfets and do you ever plan to manufacture an ganfet amp? Hopefully, you could have some options to purchase with a ganfet amp such as a high current power supply and other options. Thanks if you have time to answer and sorry this is 🙄so long.
Switch mode poser supplies have just destroyed the old standard for judging amplifiers. Namely, the heavier the better. Such is progress.
It keeps both the shipping weight and the monetary costs overhead factor down. For the companies manufacturing them. ie. Offshore somewhere in some back lane located in Taiwan.
Thanks!
I bought a Aiyima A07 pro and upgraded the power supply to 48v 5a and the AMP gets warm to the touch. Is this normal?
Paul, would a switching power supply benefit from an AC to DC to AC regeneration power source, like PS Audio’s PowerPlant?
Nah, you need to go from AC to DC to AC to DC fourteen iterations to see the real improvements.
Sir which is best for professional home audio system? Is it active crossover or passive crossover..?
I guess the active ones would be much more accurate and stable over time.
Hey Paul are Linn Chakra amplifiers class D?
Novato was the original home of Wilson Audio
I most cases replacing a "switch mode supply" with a well designed "linear" supply in a class-D Amp will improve the sound. The "switch mode" supplies are just used to keep the weight and the price point down. It's more about marketing than audio quality. Of course Paul did NOT mention why you NEVER see "chopper-switch-mode" power supplies in Class A/A-B amps.
@Douglas Blake name five manufacturers that are using a switching power supply in a class AB amplifier.
@Douglas Blake We are watching Pauls channel....which talks hifi...not AV. You can't name one hifi manufacturer??? That's about what I expected. I see you willing to reply to many people's comments. That's great, but at least pass on the correct information before you write something
@Douglas Blake bullshit - Yamaha AVRs don't and my last Denon also had none
@Douglas Blake Doug...you are diverging. I'll ask again. Name five manufacturers and the models that use a switching power supply in their class AB power amplifier. You are the one that spoke nonsense and now you can't answer the question. And even though I shouldn't have to go down your rabbit hole because you can't answer my direct question and you are diverging, AV manufacturers are still using a very good amount of linear power supplies. You are wrong with that comment also. You're acting as if 80% of Manufacturers are now using a switching power supply in their AV receivers. Wrong again.
@Douglas Blake the Yamaha is w years and the power supply hasn't changed in the newest models - be quite when you have no clue how! The power supply is one of the marketing points for Yamaha Aventage AVRs
You could just as easily put a switching power supply in a class AB amp and it would be fine.
nice
Do the output devices on Class D amps exhibit crossover distortion? The solid-state, Class A amps I used to build, employed MOSFET's, in TO-3 packages, operated at 90 C, at 2 Amps of bias Current to achieve, Class A operation, by the designer's topology. AudioAmateur/Old Colony would sell the boards for 25 bucks/channel. I built the linear PS to easily deliver 4 Amps of bias Current, for more power. By building my own linear PS, 800KVA toroidal transformers were 90 bucks/channel, HEXFRED diodes, a couple of bucks a piece, large filter capacitance, from a surplus House, CHEAP, double bypassed those for less Inductance, as per J. Peter Moncreiff's instruction, in His Journals. Heat sinks relatively inexpensive too. I wouldn't pay the price, compared to someone else designing, building, marketing, etc for retail. I'm just too cheap, plus the learning experience is enriching. Yet the difference between operating the amps at 0 Amps bias current and 4 Amps bias current was amazing. Eliminating the amp of crossover distortion from the Transistors was ,"Magical", vis a vis sound quality. Today, my kit built, EL 509 based, Single Ended, Valve OTL I use, is 3% efficient, delivering 7 watts at 16 Ohms, 4 watts at 8 Ohms, so I use Lowthers at 15 Ohms and Raals at 16 Ohms, plus Stax ear speakers. I'm addicted.
@Douglas Blake Thanks for the reply. I've never listened to a Class D, but maybe I will look at some of the kits, where the boards are already stuffed and all that's required is to also purchase the PS and chassis.
@Douglas Blake I've read about the NCORE line from Hypex, situated in Maylasia, although not sure they'll sell to an individual. I'll check out the Aiyima. But as of now, I'm in the middle of a Transcendent Sound," Slider", preamp, which employs zero feedback and the venerable, although now JJ Electronics manufactured 6386 compressor tube for variable gain AND a phono stage is included. I really don't like point to point wiring though. My eyes aren't what they used to be. I appreciate your advice, again thanks.
Peavey IPR2 all the way up baby !.!.!.
Back in the mid "70's as a Kenwood Rep, I was travelling with the Kenwood High Speed Clinic. I would go to HiFi stores and set up a test rig with a signal generator sending a 10Khz squarewave into any amp anyone brought in, crank the amp to stated power out into an 8ohm load and measure slew rate and rise time while reviewing the look of the squarewave out on the scope. The Kenwood was lab perfect with a 10Khz squarewave at full power. Very few others even came close! e.g. Yamaha tended to use quasy-complimentary outputs and even a sinewave looked bad!
Sony had just come out with switching power supplies in their amps. After 3 in a row literally went up in smoke, I refused to test anymore switching supply amps. Fortunately they had signed wavers and the units were under warranty. I hope the design has come far enough since then! My concern being claims of a tiny class D amp at maybe 500W @ 4ohms from a wall wort supply?
I'm not sure why the industry still toys with the idea of switch mode. It should stick to phone and laptop chargers etc and stay FAR away from audio or RF circuits.
"Kenwood High Speed Clinic" This has to be a joke.
@Douglas Blake i’m a class A fan boy from linear power supply through preamp through amplifier. I build my own from scratch
But I will say with these new GaN FETS once they have them dialed in and they perfect them I think we will have some petition where might be difficult to tell the difference between a class A and a class D. And it will be a good thing for conserving power in people who live in hot desert climates and don’t have air conditioning in their room
@Douglas Blake The chip may be capable but the designer and the implication
Still does not quite come out sounding like class A
@Douglas Blake 👍
I have 11 Peavey IPR2 7500 on my rack, Jesus Christ.!.!.! We talking power
I'm sorry but all this technical stuff confuses me. I'm not into Hi Fi for the tech I'm in it for the music. Does Class D sound as good as Class A or AB? Seems some think so and others say it doesn't, and then there is the debate about solid-state verses Valves (tubes). Tubes sound better seems to be the prevailing opinion (that's why SS designers always aspire to sound Tube-like).
To me if its hot and inefficient but sounds great then that't the way to go. If it can be efficient and lightweight and sound as good then that would be the way to go. From what I understand Class D is getting closer to AB and AB is getting closer to A but if you want the most pleasurable/natural audio sound (and isn't that the goal of High Fidelity Audio) Class A with Tubes seems to be the gold standard at this point in time.
@Douglas Blake Thank you for your response. I agree with you that Class D amplification is good and is useful and the quality of audio reproduction is getting better but if it really sounded as good as Class A or even Class AB why do all the high-end designers (like the Late B. H. King or Nelson Pass) still design Class A or AB and why would PS Audio promote their BHK series as their top-of-the-line amplifiers over their own Class D amplifiers?
As I said in my original post for me it's about the sound (and I don't listen to the class D amp in my TV, I run my TV through my outboard DAC and through my Class AB amplifier because it sounds better. Class D is good but isn't as good as A or AB, maybe in another 30 years it might get close.
Tubes and transistors can sound alike - depends upon the circuit design. Tubes, alas, degrade with use - they do not "break-in" and sound better, contrary to what the "golden ear" crowd claims!
@@terryjefferylee6314 Like anything else there are good and bad sounding Class D amps just like good and bad sounding Class A AB. It comes down to being a religious war where newer designs threaten old school thinking and egos. I've owned many SS Class A AB as well as tube amps, and a few Class D amps. Some are excellent while some are over priced for audiophools because higher price equates to better sound. You can see it for yourself in the audio rags. The higher priced gear is always ranked higher.
As a business PS Audio is smart for catering to both crowds - old school traditional and open minded adopters of newer tech.
In audio World super teacher, professor is sir you❤❤❤
A second reason that Class D amps have small power supplies: They don't waste half of the power supply's output by turning it into heat. A Class AB amp that makes 100 watts into the load will need a roughly 200 watt power supply. A 100 watt Class D amp may only need a 115-120 watt power supply to do the same thing.
I was surprised that he didn't mention this factor.
Modern class d is excellent! I just switched and won't be going back.
Watch out for scammers on this channel! They want you to believe that you have been selected as one of Paul’s winners. Don’t dm them!
Right; for the sake of others, these can be reported with the ellipses on the right of these comments.
Damn, I was hoping they were giving away class d amps
@@geddylee501 With linear or switching power supplies?
More interesting meetings at ps audio, then.
Thanks for the explanation,but honestly, I'm more confused now than I was at the outset...lol...with all of the gains we have seen in class D over the last few years, some are saying that class D is the future. Anyone here in the comment section have an opinion on this?
I want to know how sharp the knife has to be for that chop chop.
@Douglas Blake Paul is not so good at explaining technical stuff.
@Douglas Blake Amen. More money than brains in some cases. There is only so much you can brag on.
@Douglas Blake My point was that he fails on that account as the OP wrote.
I guess I came right in time. 3 hours after released of this video.
In time for what?
GaN technology is going to change all this, allowing a Class D to sound just as good as Class A
It's not cheap, but it's relatively inexpensive for what you're getting
The GaN 1 is only $1299 right now. Pretty good for 200w x2
Yeah right. New tech of the month ;-)
Just for the record, Class D is not digital. The D stands for somerhing else. Hey Paul, what does the D stands for?
It doesn't stand for anything. It was the next available letter.
Class D is blasphemy! Every morning I fry my bacon and eggs on my mini fridge sized Class A amp.
Why do your high-end crap get that warm?
@@Harald_Reindl I hope you didn't actually think I was being serious. I'm all for class D.
@Douglas Blake tell me something new - don't change the fact that my Yamaha is colder then my f**k cable modem
@@jasonkillsformomy well, audiophiles are known as general dumb and so everything is possible
@@Harald_Reindl That's because your cable modem has to do a ton of woke censoring.
Paul you were all over the place in this one. You never answered the question. It was a very direct one.
i dont want my music chopped up. Thankyou very much
I just want it now...chop chop!
I would like a more detailed explanation please.
@Douglas Blake and your point in some comment I had to scroll for? I for one like the geek stuff. Paul did not go to the geek side, imo, on this topic. I’m confused in your reply.
Half of your head is missing
Keep switch mode FAR... So VERY far away from my audio. My listening room is segregated to it's own circuit in the house, with it's own db box.
You are not allowed to even plug in a phone to charge here.
All equipment was home made, so power supplies also have 47nf caps over the diodes (BY229) in the rectifier to assist with cleaning off crap that comes from mains and are translated to the 30 or 50v path.
Satan himself invented switch mode psu just to mess with us purists.
Switch mode is a terrible solution to a world wide design flaw. Mains should have been 200hz globally. No way to recover from that now, unless you are willing to make all current electronics obsolete and start again.