I am not saying that Class A sounds 'bad', just that exactly with proper engineering, you can get just as good sound, and with added benefits regarding size, power consumption etc.
We going from bad to worse here, just looking at 3 sentences of the theory concerning amplifier classes will tell you straight away why its impossible for any other class in existance till this presant day to be better than Class A for sound quality, there is heavy price to be paid for this quality.
Class D still have a very long way to go before they can even compete on sonic quality of class AB in my honest opinion, I ve auditioned some class D amps costing an arm and a leg and they cant even match a linsey hood lin type amp I built as a teenager even less so a modern design. They make great subwoofer amps for cars though, ive got a 2000 watter in my car that can make the number plates fall off but thats for spl competions not high end. With time they will improve Im sure.
Greetings Andre, nice to see some South Africans here, from ex South African.
Class D still have a very long way to go before they can even compete on sonic quality of class AB in my honest opinion, I ve auditioned some class D amps costing an arm and a leg and they cant even match a linsey hood lin type amp I built as a teenager even less so a modern design. They make great subwoofer amps for cars though, ive got a 2000 watter in my car that can make the number plates fall off but thats for spl competions not high end. With time they will improve Im sure.
Greetings Andre, nice to see some South Africans here, from ex South African.
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"just looking at 3 sentences of the theory concerning amplifier classes will tell you straight away why its impossible for any other class in existance till this presant day to be better than Class A"
I'm not so sure about that. Class A depends on the output devices themselves being linear input to output. None really are. But timing in switching points (which is what determines class D linearity) can be very linear, the output devices just have to go off and on at the optimum junctures, not try to keep a linear transfer characteristic. If the output devices are where the action is (and that's sort of the unspoken assumption with class A power amplifier glorification, isn't it?) then I think class D wins.
I've also heard and built class A amplifiers, once thought that was the best way to go. I got my first class D amps to laugh at them. So I learned. You can keep your class A output stuff. Really. Have you REALLY heard a good class D amp (one made in the last 5 years or so)?
I'm not so sure about that. Class A depends on the output devices themselves being linear input to output. None really are. But timing in switching points (which is what determines class D linearity) can be very linear, the output devices just have to go off and on at the optimum junctures, not try to keep a linear transfer characteristic. If the output devices are where the action is (and that's sort of the unspoken assumption with class A power amplifier glorification, isn't it?) then I think class D wins.
I've also heard and built class A amplifiers, once thought that was the best way to go. I got my first class D amps to laugh at them. So I learned. You can keep your class A output stuff. Really. Have you REALLY heard a good class D amp (one made in the last 5 years or so)?
And I dont plan wasting my time listening to more for high end use, theyre fine for my cars subwoofers.
Im not prepared to to name a manufacturer openly on the net, last time I did I got hate mail and mail from the company in question but lets just say this amp falls in the more than 5000 euros category and the company has been very long in the industry.
I dont like getting into these kind of discussions, transistors arent perfectly linear but they arent perfect switches either and then there are other pitfalls such as the filters and we can go on , maybe you design them and would better know what they are, in future I plan to get into their design and build one or two to do some tests but I have no fear that class D will actually be able to top Class A design for very high end design. They will become mainstream but not because of sound quality but energy efficiency.
When I look at the high end companies product lineups nowadays I always see class D amps and the very fact that they are usually only offered as either subwoofer amps or home theather amps tells me all I need to know, they are sticking with Class A and AB amps for their critical listening amps, now why would that be ?? I dont think I need to answer this.
Exactly, if there is another amplifier with better SQ than class A, then look for the problem in the design of the class A amp. On the other hand, if you are not a SQ nut, forget about class A.
At this stage it seems like there are more ex South Africans than South Africans in the world. 🙂
We'll be seeing more and more ex South Africans methinks 🙂
Has anyone from the "mufled trebles" club done a proper audition by biasing a class A amp lower or are all the anecdotes based on comparing completely different amps?
Any evidence that reducing the bias of a class A amp improves the sound in any way?
While not trying to argue with people's perceptions, is it not possible the "mufled trebles" are just coincidental? Class A amps often use huge amount of PS capacitance, not necessarily of the highest quality and massively parallel output stages. Both IME can contribute towards relative lack of focus and immediacy in the highs and an overpowering quality of the bass. The massive mechanical construction and by necessity, equally massive support structures, can also have an effect on sound.
It is quite amusing to try and do the "green" thing at the precise time when mother nature is making such an overwhelming display of its futility. How many class A amps does it take to power a volcano?
If 1 percent of brain energy waste to dennie the obvious was used
to search and research for the solution, then amplifiers would sound better.
People waste too much time being stubborn... this is what makes the "status quo", the stablishment goes on..nothing changes. folks just goes trying to convince others without asking to themselves, if they, really, in their intimate thinkings, if really believe in the theories they espouse, if was really tested or if is only "thinking".... based in "i think so"....not a scientific thing.
More interesting, also strange, people use science, theories science based, to support non scientific behavior... have not listened, have not tested, do not know the real things and goes discussing.
I know, to survive happy we need to fool ourselves...to believe, for instance, the wife is good, the work is fine, the money is good, the future will be better..we go fooling...but i do not understand why people fool themselves even in their most precious hobby, something is passion, as audio amplifiers is to me and for others..why they do that with themselves.
Have only to listen and to compare with an AB amplifier..what is the trouble or hard work to do that... doing will realise...if not..call other to evaluate..as we use to be biased...call a children... play a bell....make recording and reproduce in the class A and reproduce in the Class AB..then ask if one of them is sounding alike playing below a pillow.
Talk, talk, talk, and not too much suggestions.. all this effort to dennie the obvious....much more interested in " I am rigth and you wrong " then to really know the truth.... when the truth means we all are winners..as we remove our feet from the sticky and smelling lame of ignorance.
regards,
Carlos
to search and research for the solution, then amplifiers would sound better.
People waste too much time being stubborn... this is what makes the "status quo", the stablishment goes on..nothing changes. folks just goes trying to convince others without asking to themselves, if they, really, in their intimate thinkings, if really believe in the theories they espouse, if was really tested or if is only "thinking".... based in "i think so"....not a scientific thing.
More interesting, also strange, people use science, theories science based, to support non scientific behavior... have not listened, have not tested, do not know the real things and goes discussing.
I know, to survive happy we need to fool ourselves...to believe, for instance, the wife is good, the work is fine, the money is good, the future will be better..we go fooling...but i do not understand why people fool themselves even in their most precious hobby, something is passion, as audio amplifiers is to me and for others..why they do that with themselves.
Have only to listen and to compare with an AB amplifier..what is the trouble or hard work to do that... doing will realise...if not..call other to evaluate..as we use to be biased...call a children... play a bell....make recording and reproduce in the class A and reproduce in the Class AB..then ask if one of them is sounding alike playing below a pillow.
Talk, talk, talk, and not too much suggestions.. all this effort to dennie the obvious....much more interested in " I am rigth and you wrong " then to really know the truth.... when the truth means we all are winners..as we remove our feet from the sticky and smelling lame of ignorance.
regards,
Carlos
Well, I've started with class B, tried AB and every time the closer I've got to class A, the better the sound. My current amplifiers can switch between AB and A, I use class B for AV and classA for serious listening.
It takes huge amounts of capacitance with a Class A amplifier to reduce PSU ripple to an acceptable level.
Using good quality separate regulated PSUs, and even better, with decent front end regulation as well,
will take a well designed Class A amplifier to an even higher level of performance.
You are then likely to find that even very low level ambience sounds so much more natural, and recognisable,
than with even the better Class AB amplifiers.Of course, this also improves focus and reveals detail that you
may not have noticed previously, AND with no added sibilance or harshness.
SandyK
Using good quality separate regulated PSUs, and even better, with decent front end regulation as well,
will take a well designed Class A amplifier to an even higher level of performance.
You are then likely to find that even very low level ambience sounds so much more natural, and recognisable,
than with even the better Class AB amplifiers.Of course, this also improves focus and reveals detail that you
may not have noticed previously, AND with no added sibilance or harshness.
SandyK
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