@@terrycain1811 Class A has no advantages sound wise either, but the famous (class A) Musical fidelity A1 was class AB really. Still warms the room though.
In 1965 Clive Sinclair in the UK marketed a Pulse Width Modulation audio amplifier (class D). Sold ready built or in kit form, it had several problems such as low power and interference to radio and TV. Clive invented pocket radios, pocket TVs and electronic watches as well as Britain's best selling home computer. As a youngster I built his Micro Radio kit the size of a matchbox.
While Sir Clive was definitely an innovator, most of his creations were let down by poor build quality. The Black Watch was a famously epic disaster, and certainly wasn’t the worlds first electronic watch.
I recently bought one of those popular Class D amplifiers from Amazon, the Fosi V3, along with a 48V/5A switching power supply. Without getting into how the V3 sounds (brutally bright and in your face, almost shouty, compared to the typically warmer sound of Class AB. Suffice to say, I prefer Class AB over D), I've noticed that the Fosi amp does get rather warm, especially when idle, so it's clearly drawing a significant amount current when idle, otherwise the amp wouldn't get so warm. what gives? the Fosi V3 uses the popular TPA3255 chip from Texas Instruments, which you'll find in a lot of these lower-end Class D amplifiers.
New AB amps don't run hot like the vintage stuff did - my recent model Yamaha A-S1200 barely gets warm at all, even when run hard. The NAD M23 is Class D, and what I would pick if buying today, that is one Hell of a sweet amp.
@Paulmcgowanpsaudio - do you anticipate that at some point in future class A/AB will become completely redundant/obsolete and class D will be able to match all the sonic characteristics of Class A/AB? If yes - any guesses as to when that might happen?
I know your question is directed to Paul, but if I may but in for a second... My answer would be that it already has. PSAudio's Stellar amps demonstrate that very nicely. A growing number of dirt cheap "chip-amps" are producing power and sound right in step with the "big boys". Those based on the TPA3255 power chip are especially impressive. The truth is that better audio is getting cheaper and cheap audio is getting better ... all the time.
There are people that have multiple systems they listen to in their homes. Tubes, A/B, vintage and Digital systems. Along with different types of speakers. They all have different characteristics along with the different types of music they listen to and what they want to focus on, different genres. Think of as different flavors of ice cream and what you are in mood for. Match the system to what they are listening to. There are many different genres and sub genres of music. Vocals etc etc. etc. Paul is a good example. He has numerous audio systems in his house he listens to including his iPhone and car stereo.
@@davidfromamerica1871 I knew a guy like that. In order to play modern music, he would make us wait for most of an hour while he hooked up his class AB amp then did REW sweeps to ensure it was set properly... then he would play 2 or 3 songs, and the cycle would repeat with different gear for his next selections. Never did know why anyone would do that, but yeah, some people are that far out there... Me, I have a system that serves me well enough in every case. Want to hear some music... grab the keyboard, open the Playlists, pick one that catches your fancy and press Enter... never more than a few seconds to get to the fun part.
@@Douglas_Blake_579 we meet again 🙂that's very re-assuring for me - already have an Aiyima A07 (TPA3255-based) - put in Burson v5i op-amps and greatly enjoying the set. Ordered a Fosi Audio V3 (same chip, can op-amp roll as well) - which is supposed to have better components as per the video you shared 👍
@@dipanjanbiswas6580 I wish I had more time with the V3 sonically it's like the A07 with what I thought was a bit more oomph in the very low end ... The one I measured was a customer's unit and the actual task was to check the Op-Amps for fakes (They weren't) so I only had about 2 hours with it. .
Class AB doesn’t have all that FILTERING on the output section. Class D require large filtering capacitors (Mylar or polyester type) along with large big inductors.
I would not call a 10uh inductor "large big". Most are about the size of a $1.00 coin. The filter caps are typically 1uf or less ... about the size of a tic-tac (candy). The filtering removes the 300k to 500k switching from the PWM driver. At those frequencies the parts get pretty small.
If you bought it and you don't know what it is, it's not class A. So if it's old, it is probably A/B and if it's newer it might be class D. You'd have to specifically ask for a class A, or if the seller is suggesting a class A he will tell you right away
While it did exist in PA and various self-powered speakers Class-D didn't really get a consumer foothold until the Chinese manufacturers picked up on the Tripath chips and began marketing them as "desktop amplifiers" in the early 2000s. Since then Class-D has progressed rapidly to the point where most recently end-users are actually surprised to discover their own equipment is Class-D and they didn't even suspect. PSAudio's Stellar and Sprout lines are Class D as are many from other well esteemed manufacturers such as Marantz, Cambridge and Crown.
The simplest test? Pick it up. With the monster heat sinks and transformers most AB amplifiers are very heavy. Class-D needs none of that and often weighs considerably less.
Obviously a question for PS Audio... FWIW, depending on the tube and how it is biased, it may run for 20 years without issue. Small signal tubes that are not moving much current last a very long time. Also, likely not expensive to replace, so you can keep a fresh one and after 5 years pop it in and see if you notice a difference. If not try again in a few years.
You could try sticking it in a EMC (Electromagnetic Compatability) chamber and just look at the massive radiated noise and hash from the Class D compared to the stony silence of the Class A / AB amplifier. Class D brings two things. Its cheaper to make overall, and it's "New" in a market starved of anything worthwhile for over two decades, where New is always better....only it isn't.
1980’s Carver “magnetic field” power amps were not class AB, correct? Weren’t they class D? Stayed cool virtually all the time, only slightly warm at or near max power. Weighed next to nothing.
@@gotham61 So what class did they operate? Or were they some sort of hybrid or something else given the unique switching power supply? Hard to believe they ran even a few watts under class A as cool as they were. AB from the get go?
I had a H/K PA5800 amp. 5 channels rated at a laughable 90 watts per channel. Was head and shoulders above the amp in the old Onkyo/Integra receiver’s built in 100 watts. Still have it in a closet as a back up spare in case my Outlaw (ATI) amp ever goes out. The H/K was a great sounding amp that punched above its weight but never got warm unlike the Outlaw. I always wanted a few H/K Citation amps. Too bad Harmon pretty much eliminated the Harmon/Kardon line. They were the best bang for the buck amps ever.
Class D: another opportunity for prejudice among audiophiles. Some people joke about Class D. You just know there's a brand or 2 out there of Class D amps that would erase the smirk on those people's faces forever. I'm still into Class AB or preferably Class A, but like the compact disc thrust upon us; in 8 or 9 years, you can pretty much count on Class D being our main choice and maybe even virtually our only choice, except for vintage equip. and some esoteric brands. If the Class D amps are lightweight that will be good news for the incredible amount of 70 year olds by then. They will represent the biggest age group of our population. Expect cds or digital something to be the popularity king. Older people need brighter sound with their upper frequency hearing decline. Maybe if vinyl is still popular, those moving coil cartridges from the 1980s with their extreme rising high end will come back. 30 years ago, it was hard to find a moving coil cartridge that didn't have a distinctly rising high end. Maybe bright CBS Mastersond half speed master lps will become legendary and huge collectors items. Vintage reel to reel tapes might be nostalgia value only with its duller sound. Quite a few companies throughout the world are currently offering prerecorded reel tapes dubbed directly in real time from studio masters. Kind Of Blue and Blue Trane are available in Europe. Other titles are available right here, as you may know from the audio shows. What sound does a tape deck make before and after Dolby Noise Reduction? Answer: Shhh....Quiet.
So we all know at least the basics of how each class works and some here will run circles around the rest of us. That said, to what do you attribute the lack of presence in a class D amp? The reason I bring this up is because something like presence is usually spoken of as a function of frequency response that could be EQ'd away but intuitively I just know there's more to it than that. My take is about a balancing act between the modulating technique and the output filtering. I have opinions about that but I still want folks to think I'm from this planet.
Sorry but this is just bull crap and old world stuff. I just got the Marantz PM KI Ruby.. it weighs more than many hyped klass AB stuff(Hegel). And sound far warmer and has a much better soundstage and presence than any class AB stuff that has been here. It’s not the class that decides the sound.. it is the circuit around it and implementation:)
@@donpayne1040 Usually with switching supplies, giving the advantage of putting the amplifier's outputs on a tightly regulated voltage. Older linear supplies can be used if they don't rebound or sag after transients.
Easy - if it keeps you warm in the winter..it's Class A/B
Depends on the biasing.
Or your electric bills high suddenly
All of u are misspoken. Class A is the only one which heats up. To such a degree that it actually heat up a room.
@@terrycain1811 Class A has no advantages sound wise either, but the famous (class A) Musical fidelity A1 was class AB really. Still warms the room though.
In 1965 Clive Sinclair in the UK marketed a Pulse Width Modulation audio amplifier (class D). Sold ready built or in kit form, it had several problems such as low power and interference to radio and TV.
Clive invented pocket radios, pocket TVs and electronic watches as well as Britain's best selling home computer. As a youngster I built his Micro Radio kit the size of a matchbox.
Bare in mind that the spectrum still looks modern today. That's good design.
While Sir Clive was definitely an innovator, most of his creations were let down by poor build quality. The Black Watch was a famously epic disaster, and certainly wasn’t the worlds first electronic watch.
Didn’t Bob Carver make a class D amp in the late 1979s? If I recall it was a small silver “cube” shaped amp with LED indicators on the face
Sorry, late 1970s..
I enjoyed having one of his programmable pocket calculators in the mid-1970s.
The first class D amps I recall were the TacT Millennium in 1998, and the Sharp SM-SX100 around the same time
No ordinary-looking amplifier from the 1970s or 1980s is class D.
All 1970s Harman/Kardon amplifiers are class A/B --- and damm good ones at that.
If you have a good quality
A/B, keep it, don’t get rid of it.
You can always buy a Class D anytime.
The Sony TA-N88b introduced in 1977 is a PWM amplifier, which imho can be considered class D
Sony sold class D-amps in the late 70's. But they didn't catch on and become common until much later.
I recently bought one of those popular Class D amplifiers from Amazon, the Fosi V3, along with a 48V/5A switching power supply. Without getting into how the V3 sounds (brutally bright and in your face, almost shouty, compared to the typically warmer sound of Class AB. Suffice to say, I prefer Class AB over D), I've noticed that the Fosi amp does get rather warm, especially when idle, so it's clearly drawing a significant amount current when idle, otherwise the amp wouldn't get so warm. what gives? the Fosi V3 uses the popular TPA3255 chip from Texas Instruments, which you'll find in a lot of these lower-end Class D amplifiers.
New AB amps don't run hot like the vintage stuff did - my recent model Yamaha A-S1200 barely gets warm at all, even when run hard. The NAD M23 is Class D, and what I would pick if buying today, that is one Hell of a sweet amp.
The power supply will have giant transformer inside for class A or AB The amp weights a ton if it's class A, or AB.
@Paulmcgowanpsaudio - do you anticipate that at some point in future class A/AB will become completely redundant/obsolete and class D will be able to match all the sonic characteristics of Class A/AB? If yes - any guesses as to when that might happen?
I know your question is directed to Paul, but if I may but in for a second... My answer would be that it already has.
PSAudio's Stellar amps demonstrate that very nicely.
A growing number of dirt cheap "chip-amps" are producing power and sound right in step with the "big boys". Those based on the TPA3255 power chip are especially impressive.
The truth is that better audio is getting cheaper and cheap audio is getting better ... all the time.
There are people that have multiple systems they listen to in their homes. Tubes, A/B, vintage and Digital systems. Along with different types of speakers.
They all have different characteristics along with the different types of music they listen to and what they want to focus on, different genres.
Think of as different flavors of ice cream and what you are in mood for. Match the system to what they are listening to.
There are many different genres and sub genres of music. Vocals etc etc. etc.
Paul is a good example. He has numerous audio systems in his house he listens to including his iPhone and car stereo.
@@davidfromamerica1871
I knew a guy like that. In order to play modern music, he would make us wait for most of an hour while he hooked up his class AB amp then did REW sweeps to ensure it was set properly... then he would play 2 or 3 songs, and the cycle would repeat with different gear for his next selections. Never did know why anyone would do that, but yeah, some people are that far out there...
Me, I have a system that serves me well enough in every case. Want to hear some music... grab the keyboard, open the Playlists, pick one that catches your fancy and press Enter... never more than a few seconds to get to the fun part.
@@Douglas_Blake_579 we meet again 🙂that's very re-assuring for me - already have an Aiyima A07 (TPA3255-based) - put in Burson v5i op-amps and greatly enjoying the set. Ordered a Fosi Audio V3 (same chip, can op-amp roll as well) - which is supposed to have better components as per the video you shared 👍
@@dipanjanbiswas6580
I wish I had more time with the V3 sonically it's like the A07 with what I thought was a bit more oomph in the very low end ... The one I measured was a customer's unit and the actual task was to check the Op-Amps for fakes (They weren't) so I only had about 2 hours with it. .
Class AB doesn’t have all that FILTERING on the output section. Class D require large filtering capacitors (Mylar or polyester type) along with large big inductors.
I would not call a 10uh inductor "large big". Most are about the size of a $1.00 coin.
The filter caps are typically 1uf or less ... about the size of a tic-tac (candy).
The filtering removes the 300k to 500k switching from the PWM driver. At those frequencies the parts get pretty small.
Horn speakers, integrated amp, all American made. $4K budget. What are your suggestions?
Can't find an owner's manual online?
If you bought it and you don't know what it is, it's not class A. So if it's old, it is probably A/B and if it's newer it might be class D.
You'd have to specifically ask for a class A, or if the seller is suggesting a class A he will tell you right away
PS Audio Elves & Pixies your new Direct Stream DAC has just had a blistering review In Stereophile Well done to everyone!
Class D wasn't a thing in the 70s and early 80s?
While it did exist in PA and various self-powered speakers Class-D didn't really get a consumer foothold until the Chinese manufacturers picked up on the Tripath chips and began marketing them as "desktop amplifiers" in the early 2000s.
Since then Class-D has progressed rapidly to the point where most recently end-users are actually surprised to discover their own equipment is Class-D and they didn't even suspect.
PSAudio's Stellar and Sprout lines are Class D as are many from other well esteemed manufacturers such as Marantz, Cambridge and Crown.
Mackie HR824 active studio monitor used class D amp back in 1997
Paul - any chance you are going to update the M1200 with newer modules that are available now?
Or you could drink a glass of refreshing, chilled lemonade while you look up the model number and specs online???
I think Sony experimented with PWM/PCM amlifiers around 1980. Don't know whether they qualify as class D.
Yes they are and yes they sold them commercially.
The simplest test?
Pick it up.
With the monster heat sinks and transformers most AB amplifiers are very heavy.
Class-D needs none of that and often weighs considerably less.
Lightness only tells you that the power supply is switch mode. Class AB amplifiers can be light.
@@MrsZambezi
But the odds are that an AB amp is going to weigh more. Finding a rare exception does not disprove the rule.
That tube front end brings up a question. How often do you have to change the tubes?
Input tubes I assume ? If so, most likely almost never.... Output power tubes are the ones that can take its toll over time.
Obviously a question for PS Audio... FWIW, depending on the tube and how it is biased, it may run for 20 years without issue. Small signal tubes that are not moving much current last a very long time. Also, likely not expensive to replace, so you can keep a fresh one and after 5 years pop it in and see if you notice a difference. If not try again in a few years.
You could try sticking it in a EMC (Electromagnetic Compatability) chamber and just look at the massive radiated noise and hash from the Class D compared to the stony silence of the Class A / AB amplifier. Class D brings two things. Its cheaper to make overall, and it's "New" in a market starved of anything worthwhile for over two decades, where New is always better....only it isn't.
Panasonic SA XR series from the early 2000's.
1980’s Carver “magnetic field” power amps were not class AB, correct? Weren’t they class D? Stayed cool virtually all the time, only slightly warm at or near max power. Weighed next to nothing.
Not class D. They used a switched mode power supply to eliminate the heavy transformer.
@@gotham61 So what class did they operate? Or were they some sort of hybrid or something else given the unique switching power supply? Hard to believe they ran even a few watts under class A as cool as they were. AB from the get go?
@@36karpatoruski It used a sliding bias class A/B circuit.
Class D’s don’t get warm at idle* Apart from Pascal and some Powersoft which are 100% Class D and get roasting hot at idle.
Just lift it. if its light, its D, if its heavy, its AB :)
harman/kardon is the best.
I had a H/K PA5800 amp. 5 channels rated at a laughable 90 watts per channel. Was head and shoulders above the amp in the old Onkyo/Integra receiver’s built in 100 watts. Still have it in a closet as a back up spare in case my Outlaw (ATI) amp ever goes out. The H/K was a great sounding amp that punched above its weight but never got warm unlike the Outlaw. I always wanted a few H/K Citation amps. Too bad Harmon pretty much eliminated the Harmon/Kardon line. They were the best bang for the buck amps ever.
Pick it up? A/B will hurt your back, D won't!
Class D may not hurt my back but it sure hurts my ears 😬 Inefficient as they may be, it's got to be Class A or AB for me.
Yamaha did some class D 1990
Class D: another opportunity for prejudice among audiophiles. Some people joke about Class D. You just know there's a brand or 2 out there of Class D amps that would erase the smirk on those people's faces forever. I'm still into Class AB or preferably Class A, but like the compact disc thrust upon us; in 8 or 9 years, you can pretty much count on Class D being our main choice and maybe even virtually our only choice, except for vintage equip. and some esoteric brands. If the Class D amps are lightweight that will be good news for the incredible amount of 70 year olds by then. They will represent the biggest age group of our population. Expect cds or digital something to be the popularity king. Older people need brighter sound with their upper frequency hearing decline. Maybe if vinyl is still popular, those moving coil cartridges from the 1980s with their extreme rising high end will come back. 30 years ago, it was hard to find a moving coil cartridge that didn't have a distinctly rising high end. Maybe bright CBS Mastersond half speed master lps will become legendary and huge collectors items. Vintage reel to reel tapes might be nostalgia value only with its duller sound. Quite a few companies throughout the world are currently offering prerecorded reel tapes dubbed directly in real time from studio masters. Kind Of Blue and Blue Trane are available in Europe. Other titles are available right here, as you may know from the audio shows.
What sound does a tape deck make before and after Dolby Noise Reduction?
Answer: Shhh....Quiet.
Just lift the thing. No weight = class D. You will also hear, there is a lack of presence in class D.
My though exactly.
So we all know at least the basics of how each class works and some here will run circles around the rest of us. That said, to what do you attribute the lack of presence in a class D amp? The reason I bring this up is because something like presence is usually spoken of as a function of frequency response that could be EQ'd away but intuitively I just know there's more to it than that. My take is about a balancing act between the modulating technique and the output filtering. I have opinions about that but I still want folks to think I'm from this planet.
Sorry but this is just bull crap and old world stuff.
I just got the Marantz PM KI Ruby.. it weighs more than many hyped klass AB stuff(Hegel). And sound far warmer and has a much better soundstage and presence than any class AB stuff that has been here.
It’s not the class that decides the sound.. it is the circuit around it and implementation:)
I have 2 class A/B amps.
I am keeping them forever until I die. I might even have them buried with me..👍🤗
Can't you have conventional transformer powersupply while amp is class D? That thing would be also heavy.
For me the many world theory is in the same can as string theory. At least until someone can present some evidence otherwise
Can you lift it with one hand? Must be class D. LOL.
Eigentakt purify, Hypex Ncore are all class D. These are state of the art
More like state of the shart
How do YOU power these things?
@@donpayne1040
Usually with switching supplies, giving the advantage of putting the amplifier's outputs on a tightly regulated voltage. Older linear supplies can be used if they don't rebound or sag after transients.
@@Douglas_Blake_579 I see.
easy. if it sounds like sh* its class D
Hk was never class A