Part 3 of the "Introduction to Audio Amplifier Classes" series. Support this channel on Patreon www.patreon.co... Email: johnaudiotech@gmail.com Thank You!
Class E and F were cursed! Only amplifying the screams of the damned! You design and build Class E/F to the detriment *of your SOUL* usually by gently biasing a matched pair of 2N666’s and running them push/pull through a series/parallel resistor network in the shape of an inverted pentagram. But be prepared, while it *pushes your sanity* it will *pull you down to HELL* but all that said, it sounds alright, not as pure as a Class A, more powerful than A/B but again, you have to use protection spells which sorta negates the additional power of the Dark Path. It’s probably not worth it, but give it a shot *if you dare* and have some parts laying around.
@@silverXnoise I made an amp once that picked up a really powerful AM radio station. It was clear as a bell. That was a bit cursed. She had a bad oscillation to her.
Thanks a lot! I didn't know anything about the physics of amplifiers but got interested after I had bought a very small one to replace my 20 year old hi-fi amp. Fascinating technology.
I'm a fan of class D amps, they sound as good as class A if you layout the board well and use proper ground planes, you also do not need a big power supply to achieve high volume.
I recently purchased an HDMI microscope for micro soldering, but I also use it for through hole soldering as my eyesight is extremely poor. So far I have actually SMD to be easier to work with ... now that I have the proper tools. But my point is, if your eyes are like mine, using a tool like an HDMI scope not only gives me better vision but also always me to sit away from the circuit in comfort. :) I guess the downside is I am now dependent on it ...
What sucks about SMD is prototyping and rework. None of that is easier compared to through hole. SMD is fine for making finished products. When one is experimenting getting to the finished design is not always a linear process. I am not a pick and place machine!
Hmmm, nice explanation but where does the gain come from ? And how is the PWM signal converted back at thevoutput. Low pass filter seems a bit simplistic.
My experience is that good Class D amps can have a lovely sound for less cost than a comparably performing class A or class AB amplifier. However, one option I considered for a speaker crossover I'm designing had an impedance up around 20 ohms at 20kHz. I discarded that option because I suspect the class D amp I want to use may not function well with such a high impedance at the top of the audio band. On the other hand, my mediocre class AB amplifiers would handle any impedance greater than about 2 ohms, regardless of the phase of that impedance.
Class AB doesn't need filtering on the output. They can safely use global feedback to ensure the output is flat regardless of the impedance of the speaker. Global feedback isn't so easy with Class D, since the inductor to filter the audio causes too much delay. I have never seen a class D power amp that was flat on a wide range of impedances. Usually just 4/8.(The inductor is matched for a 6 ohm load)
@@rich1051414 while not always necessary for class AB, a suitable RLC network on the output definitely aids stability by ensuring the output has a functional load at rf. Such an RLC network also ensures reduction in any rf from the amplifier reaching the speaker (for example during clipping), and also prevents rf resonance in the speaker lead (for example, where the speaker neutral is disconnected at the amplifier, leaving only the "active" wire going to the speaker, which I foolishly found out the hard way might destroy the output transistors of at least one amplifier) .
Clive Sinclair (of ZX80/81 fame) first sold his "X-10" Class D amplifier module in 1964. They were very unreliable though, early germanium transistors, no output filter and some bad quality control issues.
Today there are class D amplifier modules available, which can outperform class AB amplifiers without problems. F.i. the 80AM2 from ICEPower is a dual channel class D audio module with 2 x 80 Wrms with a THD+N of 0.003% a TIM of 0.0035% and a S/N of 110 dB. These parameters are also hard to achieve for class AB amplifiers. These modules work with a different PWM technology. They sum the triangle signal with the audio input signal and use a zero detector to switch the pulse on and off. Very interesting.
The greatest disadvantage is the sound, that is straight, and you have to like it, I have Class ABs and Class Ds and the ABs does sound more colored, more HIFI. I have also speakers that are straight, and you must like that sound, these are Phase Linear speakers. But if you hear my high-end B&W speakers, it's much more colored. But if you listen in my studio where I use Focal big monitors, that is totally different, also the price does.
Hifi is abbreviation of high-fidelity, so technically the "straight", transparent sound from Class D amps matches the original definition of "hifi" better 😀Genelec studio monitors, acknowledged as "standard reference speaker" in the industry, have Class-D amps inside
Seeing the sine wave output from class D amplifier , I would rather stick to class AB amplifier and lose some efficiency. 😊 Thank you for the best lecture .
Hello Sir, would you know how to find "common Ground" on those cheap Class D amplifiers e.g. Wuzhi TB21? I would like to connect VU meter board which needs common ground on ( - )
This sent me into a tailspin when I learned these use PWM. Its digital? But it looks like it's a matter of some debate. Is the audio converted to 1/0s?
5 місяців тому
I understood the PWM but didn’t get how low pass reconstructs the waveform. Can somebody explain?
Sir have you designed any circuit like 433 mhz transmitter and receiver module used in RC toys to control dc motors , or can you explain the data transmission in the 433 mhz transmitter and receiver module
Dear John, what can I do to use the whole 20 kHz frequency range (and not only 10) in 4 ohms load? Eg. change the capacitor or the inductor value? (Increase or decrease, and which one?) I have 2x160W board used TDA7498E chip, and unfortunately it has up to 10 db loss at 4 ohms, above 10-12 kHz. A big thank you in advance for your answer, and wishing you a great week
Dear John thanks for your videos you are really great ❤
Good summary of Class D, will Share!
Very nice informative video about class d .hopefully we see a practical circuit on your working bench soon
I think we need a video about what ever happened to Class E and F amplifiers.
Class g bro
Class E and F were cursed! Only amplifying the screams of the damned! You design and build Class E/F to the detriment *of your SOUL* usually by gently biasing a matched pair of 2N666’s and running them push/pull through a series/parallel resistor network in the shape of an inverted pentagram. But be prepared, while it *pushes your sanity* it will *pull you down to HELL* but all that said, it sounds alright, not as pure as a Class A, more powerful than A/B but again, you have to use protection spells which sorta negates the additional power of the Dark Path. It’s probably not worth it, but give it a shot *if you dare* and have some parts laying around.
@@silverXnoise I made an amp once that picked up a really powerful AM radio station. It was clear as a bell. That was a bit cursed. She had a bad oscillation to her.
I was just learning about class h so the next video will be really useful for me Thanks for all the information you put in these videos.
excellent explanation of class D
Your instruction vids are great. I really enjoyed your long tailed pair / differential pair one a while back
You can't put it better than that !...cheers.
Thanks a lot! I didn't know anything about the physics of amplifiers but got interested after I had bought a very small one to replace my 20 year old hi-fi amp. Fascinating technology.
Nice
Easy to understand your explanation for Class-D
Amazingly well explained.
A confusing subject for me. Thanks for lifting the fog. Cheers!
Clear explanation. Thank you very much.
Another great educational video!!
Very nice and simple explanation. thank you
Nice explanation.
Very good explanation of class D
I'm a fan of class D amps, they sound as good as class A if you layout the board well and use proper ground planes, you also do not need a big power supply to achieve high volume.
I recently purchased an HDMI microscope for micro soldering, but I also use it for through hole soldering as my eyesight is extremely poor. So far I have actually SMD to be easier to work with ... now that I have the proper tools. But my point is, if your eyes are like mine, using a tool like an HDMI scope not only gives me better vision but also always me to sit away from the circuit in comfort. :) I guess the downside is I am now dependent on it ...
What sucks about SMD is prototyping and rework. None of that is easier compared to through hole. SMD is fine for making finished products. When one is experimenting getting to the finished design is not always a linear process. I am not a pick and place machine!
Hmmm, nice explanation but where does the gain come from ? And how is the PWM signal converted back at thevoutput. Low pass filter seems a bit simplistic.
My experience is that good Class D amps can have a lovely sound for less cost than a comparably performing class A or class AB amplifier. However, one option I considered for a speaker crossover I'm designing had an impedance up around 20 ohms at 20kHz. I discarded that option because I suspect the class D amp I want to use may not function well with such a high impedance at the top of the audio band. On the other hand, my mediocre class AB amplifiers would handle any impedance greater than about 2 ohms, regardless of the phase of that impedance.
Class AB doesn't need filtering on the output. They can safely use global feedback to ensure the output is flat regardless of the impedance of the speaker.
Global feedback isn't so easy with Class D, since the inductor to filter the audio causes too much delay. I have never seen a class D power amp that was flat on a wide range of impedances. Usually just 4/8.(The inductor is matched for a 6 ohm load)
@@rich1051414 while not always necessary for class AB, a suitable RLC network on the output definitely aids stability by ensuring the output has a functional load at rf. Such an RLC network also ensures reduction in any rf from the amplifier reaching the speaker (for example during clipping), and also prevents rf resonance in the speaker lead (for example, where the speaker neutral is disconnected at the amplifier, leaving only the "active" wire going to the speaker, which I foolishly found out the hard way might destroy the output transistors of at least one amplifier) .
Clive Sinclair (of ZX80/81 fame) first sold his "X-10" Class D amplifier module in 1964. They were very unreliable though, early germanium transistors, no output filter and some bad quality control issues.
Not a good start for class D!
Thanks bro👏now I can blast my skibidi toilet brainrot music with 95% energy efficiency😙and i feel like an engineering genius🔥
Today there are class D amplifier modules available, which can outperform class AB amplifiers without problems. F.i. the 80AM2 from ICEPower is a dual channel class D audio module with 2 x 80 Wrms with a THD+N of 0.003% a TIM of 0.0035% and a S/N of 110 dB. These parameters are also hard to achieve for class AB amplifiers. These modules work with a different PWM technology. They sum the triangle signal with the audio input signal and use a zero detector to switch the pulse on and off. Very interesting.
And only 60 or something I can't remember degrees of output swing haha what a joke class a is 360 degree output and class ab 180-220 I think
Have you worked at all with ICEpower modules? These seem to be widely available in a range of wattages.
We need another video showing what happened right at the end ..🤣😂🤣
The greatest disadvantage is the sound, that is straight, and you have to like it, I have Class ABs and Class Ds and the ABs does sound more colored, more HIFI. I have also speakers that are straight, and you must like that sound, these are Phase Linear speakers. But if you hear my high-end B&W speakers, it's much more colored. But if you listen in my studio where I use Focal big monitors, that is totally different, also the price does.
Hifi is abbreviation of high-fidelity, so technically the "straight", transparent sound from Class D amps matches the original definition of "hifi" better 😀Genelec studio monitors, acknowledged as "standard reference speaker" in the industry, have Class-D amps inside
Seeing the sine wave output from class D amplifier , I would rather stick to class AB amplifier and lose some efficiency. 😊
Thank you for the best lecture .
Some people complain of Class D sounding thin or sterile (Neurochrome and Hypex), but the Cheap, TPA3116 can sound great.
Hello Sir, would you know how to find "common Ground" on those cheap Class D amplifiers e.g. Wuzhi TB21? I would like to connect VU meter board which needs common ground on ( - )
Thanks ❤❤
This sent me into a tailspin when I learned these use PWM. Its digital? But it looks like it's a matter of some debate. Is the audio converted to 1/0s?
I understood the PWM but didn’t get how low pass reconstructs the waveform. Can somebody explain?
Sir have you designed any circuit like 433 mhz transmitter and receiver module used in RC toys to control dc motors , or can you explain the data transmission in the 433 mhz transmitter and receiver module
What is producing the triangle wave input and what is the typical frequency used?
It is generated internally in the amplifier IC or the control chip. Check the datasheet for the frequency used on a particular part #.
Class D rules in car subwoofer amps!
Class D is great for the low frequency sounds
What can't an op amp alone or paired with circuitry make a good music amp? not enough gain?
Dear John, what can I do to use the whole 20 kHz frequency range (and not only 10) in 4 ohms load? Eg. change the capacitor or the inductor value? (Increase or decrease, and which one?)
I have 2x160W board used TDA7498E chip, and unfortunately it has up to 10 db loss at 4 ohms, above 10-12 kHz.
A big thank you in advance for your answer, and wishing you a great week
Check the datasheet for that chip. It should list the recommended values.
Good luck sir
Verry nice loving video
i will stick to my late 80s Aiwa Stereo Amplifier for as long as it lasts.
You failed to mention its processor module, which has been evolving.
Most used class I would say these days in consumer goods. I could be wrong.
Congrats for didatics sir
I have 4 RPA-16 amps. from ROCKVILLE. They are NON-SWITCHING CLASS H AMPS. MODERN class H amps. are the way to go for the Audiophile..
PWM modulation, for some time now, began to be called Class-D
It's still not digital.
Bro every video nice bro explain 4440 ic sound iam indian this is more populer india
Like
Ac-dc inverters do something similar lol
this may be cool to some of you i just found it www.collectionscanada.gc.ca/obj/s4/f2/dsk1/tape4/PQDD_0017/MQ53437.pdf