It seems that class ab was the standard. Then there's the amp camp that's pushing towards class a for lowered distortion that is supposed to be sweet with sensitive speakers. Then there's the camp that is pushing towards class d for cheap efficient watts and saying the quality is the same. Is this just one of those things that everyone has agreed to disagree upon whether class a makes a difference or not? It seems like it should make a difference but then if it did, why would so many people be fine and dandy with their class d's?
there is a ton of variables to take in consideration here.
about the same as the question: why do most people buy crapy micro hifi that sound like a drunk monkey in a glass store.
about the same as the question: why do most people buy crapy micro hifi that sound like a drunk monkey in a glass store.
Lol good point. I figured as much. I have a midbass I want to run from about 80-300hz that I think I'm going to class d for and just see how it sounds to me. I just don't have enough amps to be able to switch back and forth and see what my preference is :/
Newbie opinion alert!
I think some of us take this hobby too seriously. NASA have been landing people on the moon since the 60's and here we are debating the sound difference between power cables and capacitors and throw excuses when asked to do blind test. We have outgrown the thresholds of a decent sounding amp decades ago.
You can build an amp that boasts 0.000001% THD at 5,000W with 10,000V/uS slew rate but honestly what matters is your loudspeakers and how your amp interacts with them. Those (obviously exaggerated) numbers are pretty but really our ears are not that sensitive. The fact that 3-5% THD SE triode tube amps are still popular should be a good hint. Even if you say people love them because of the look, they must sound decent enough that people can stand to hear them for hours. More proof? The original Gaincard sold for thousands of dollars with cheap class AB LM3875 chipamp inside it. Surely it sounds decent enough for people to justify paying for it.
Invest most of your money on loudspeakers, not the amp.
This should be in the Lounge, by the way.
I think some of us take this hobby too seriously. NASA have been landing people on the moon since the 60's and here we are debating the sound difference between power cables and capacitors and throw excuses when asked to do blind test. We have outgrown the thresholds of a decent sounding amp decades ago.
You can build an amp that boasts 0.000001% THD at 5,000W with 10,000V/uS slew rate but honestly what matters is your loudspeakers and how your amp interacts with them. Those (obviously exaggerated) numbers are pretty but really our ears are not that sensitive. The fact that 3-5% THD SE triode tube amps are still popular should be a good hint. Even if you say people love them because of the look, they must sound decent enough that people can stand to hear them for hours. More proof? The original Gaincard sold for thousands of dollars with cheap class AB LM3875 chipamp inside it. Surely it sounds decent enough for people to justify paying for it.
Invest most of your money on loudspeakers, not the amp.
This should be in the Lounge, by the way.
there is one more thing. its not all about the EARs. its also about ow the brain decode the sound that the ears pick up. so no wounder there will never be an agreement about this subject.
I haven't any preference between A and AB, as far as sound goes they can be identical. I'm not a fan of class-D for audio range use yet, for my own reasons. AB offers the lowest noise and distortion, can be designed to drive a wide range of loads, doesn't cause EMI interference, and is inexpensive to build. They were more or less perfected for audio use 30 years ago by the big Japanese players and those designs are still in use. The tech has been implemented in a few of the best designs right on this site.
Class A has a definite advantage - the PS currents of the output stages are linear - so common impedance or magnetic loop coupling are only gain errors
where in a stage operating in Class B the supply currents are half wave rectified versions with lots of nonlinear content and can cause distortion by coupling to earlier signal stages even if the output transition smoothly
so you have to be much better at layout, signal integrity with Class B
where in a stage operating in Class B the supply currents are half wave rectified versions with lots of nonlinear content and can cause distortion by coupling to earlier signal stages even if the output transition smoothly
so you have to be much better at layout, signal integrity with Class B
I have been in audio for about 35 years.
In that time I have had class A, AB and D amplifiers.
To be honest I cant tell the difference between them.
It could be they don't vary much or my ears are so shot from mobile DJ-ing and playing electric guitar.
In that time I have had class A, AB and D amplifiers.
To be honest I cant tell the difference between them.
It could be they don't vary much or my ears are so shot from mobile DJ-ing and playing electric guitar.
i think there's no point in comparing; since what is preferred by others EARs and what my EARs wanted to hear by the way..
its like comparing different scoops of sugar and trying to figure out which tastes sweet...
its like comparing different scoops of sugar and trying to figure out which tastes sweet...
I guess I should have realized that everyone would have their own opinion on whether it's audible or not(as is everything in hi-fi audio lol) I guess the better question is have there been any blind or double blind tests testing class a or ab or d amps?
My ears are different. I can hear higher frequencies in my right ear better than I can in my left ear.
I'd be surprised if you couldn't get well-engineered and similarly-powered examples of various architectures and biasing regimes to fall under the threshold of audibility or at least get a null ABX.
When you hear a piano being played, yes you hear it with your ears and your brain. But I can't see how "what is preferred" or "how the brain decodes" has any effect on the actual sound produced by the piano.
I do agree any of the audio amp classes can be reasonably accurate.
in fact there was a long standing US$10k challenge for blind ABX detection of any amp you wanted to specify if it met a few technical requirements:
https://www.google.com/#q=clark+amplifier+challenge
and Stereophile's reviewers couldn't tell Bob Carver's $600 SS amp from their own choice of "SOTA" tube amp and idiosyncratic speakers in their own listening rooms with their choice of music when the test was Blind, after Bob nulled the electrical terminal response of his amp vs their tube amp with a handful of parts to trim output Z, frequency response...
https://www.google.com/#q=clark+amplifier+challenge
and Stereophile's reviewers couldn't tell Bob Carver's $600 SS amp from their own choice of "SOTA" tube amp and idiosyncratic speakers in their own listening rooms with their choice of music when the test was Blind, after Bob nulled the electrical terminal response of his amp vs their tube amp with a handful of parts to trim output Z, frequency response...
ABX tests lean toward a null result of 50/50, which obscures results where differences are closer to the thresholds of detection rather than obvious. Part of the problem is that ABX methodology commonly uses 30 seconds for each DUT, which is approximately three times auditory memory. More specifically, dynamic variances, which accounted for the remainder of measured and identifiable differences between stimulus, were the most difficult to test since iconic memory recollection is less than 1000ms.
For the test results to have any statistic relevance the outcome must be greater than 92% on 25 sets. Having to switch twice for three samples (two identical) draws the test out too long for subjects in the control groups. We found that subjects were forgetting A by the time DUT X was summoned, due to auditory backward recognition masking and short iconic recollection.
Sometimes the results seemed favorable and progress was being made. That wasn't the case; the other problem that took some time to uncover was subjects where spoofing the tests by learning to identify the switching transient if X returned to component A.
Double blind tests only required 2 samples and we never used the same for 1 and 2, so there was no way to spoof the test. However, samples had to be long enough for the listener to gather enough sonic information to make a decision. DBT remains the scientific standard referenced in formal research.
For the test results to have any statistic relevance the outcome must be greater than 92% on 25 sets. Having to switch twice for three samples (two identical) draws the test out too long for subjects in the control groups. We found that subjects were forgetting A by the time DUT X was summoned, due to auditory backward recognition masking and short iconic recollection.
Sometimes the results seemed favorable and progress was being made. That wasn't the case; the other problem that took some time to uncover was subjects where spoofing the tests by learning to identify the switching transient if X returned to component A.
Double blind tests only required 2 samples and we never used the same for 1 and 2, so there was no way to spoof the test. However, samples had to be long enough for the listener to gather enough sonic information to make a decision. DBT remains the scientific standard referenced in formal research.
Kouiky--may you perhaps elucidate what sort of protocols you are commenting on? ABX can be one form of a DBT, but it seems you are using them to define different things.
Audio amplifier is not everything, when we talk about a sound system. In this sound system, the quality loudspeakers have a very hard word to say. Of course, every element in the system has its importance and for this reason is not well to focus only on amplifier or only on loudspeakers.
From first appearance audio amplifier in the world until now, engineers have tried to find the audio amplifier schematic that sound good and be efficient at the same time. So, were born the working classes of transistors that were later applied to audio amplifiers, with advantages and disadvantages.
After so many years, I might say, I think, without making a mistake, as in the world has not yet designed audio amplifier that sounded good, be inexpensive and easy to build, and to dissipate very little (or be very efficient). There are various solutions but still not 100% meet this goal. Perhaps the 21st century will bring to the fore a "super audio amplifier" !!!! Let's hope.
From first appearance audio amplifier in the world until now, engineers have tried to find the audio amplifier schematic that sound good and be efficient at the same time. So, were born the working classes of transistors that were later applied to audio amplifiers, with advantages and disadvantages.
After so many years, I might say, I think, without making a mistake, as in the world has not yet designed audio amplifier that sounded good, be inexpensive and easy to build, and to dissipate very little (or be very efficient). There are various solutions but still not 100% meet this goal. Perhaps the 21st century will bring to the fore a "super audio amplifier" !!!! Let's hope.
Here is my take ... I used to run a sound board for live venues. I have a lot of experience with hearing live instruments, vocals, etc. I have built and owned several amplifiers both tube and solid-state.
One day I went to the AKFest in Detroit and heard a set of 300B Class-A Audio Note monoblocks that melted my heart. I kept going back to that room and just listening. I came home and built a Class-A EL84 amp and recently finished an entire Class-A Nelson Pass setup with Pearl 2, Mezmerize and Aleph J.
I will NEVER go back to Class-AB, D, etc.!
I am just starting a Tubelab SE 300B amplifier and can't wait to get it finished!
My system is Klipschorns at 102dB sensitivity and with Class-A and it's even harmonics, it sounds like the instruments and musicians are in the room with you. To me, that was always missing with Class-AB comparing it to sitting beside a cymbal that was just struck or the tone of a Class-A guitar amp. My "theory" is that when you listen to live sound there is no invisible filter removing the even harmonics, so I want my system to produce odds AND evens! 😀
One day I went to the AKFest in Detroit and heard a set of 300B Class-A Audio Note monoblocks that melted my heart. I kept going back to that room and just listening. I came home and built a Class-A EL84 amp and recently finished an entire Class-A Nelson Pass setup with Pearl 2, Mezmerize and Aleph J.
I will NEVER go back to Class-AB, D, etc.!
I am just starting a Tubelab SE 300B amplifier and can't wait to get it finished!
My system is Klipschorns at 102dB sensitivity and with Class-A and it's even harmonics, it sounds like the instruments and musicians are in the room with you. To me, that was always missing with Class-AB comparing it to sitting beside a cymbal that was just struck or the tone of a Class-A guitar amp. My "theory" is that when you listen to live sound there is no invisible filter removing the even harmonics, so I want my system to produce odds AND evens! 😀
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