Why would anyone want class AB amp when class A always sounds better ?

the listener has final word. 
My amps will stand up to many class A amps. 
So will my Sunfire 600 sig at class H. 

"The difference you hear with more/higher Class-A bias, is an easier, smoother, richer presentation to the sound, that’s no less dynamic and yet makes the speakers disappear, even as the music goes louder. And as a result the sound washes over you rather than being fired at you from the drivers, and that is the result of the lessening of the class-B xover distortion when you engage more and more Class-A bias."

That has been my experience as well. I experimented with various bias currents in my Integrated Amp and the sound quality improved considerably with higher values. The music had more body with a richer midrange, which was quite noticeable at low (SPL) listening levels. Nelson Pass talks about this in his "Leaving Class A" article.

Im not sure what I'm missing, as in, who cares how efficient an amp is.  Are any of us concerned with how much power we consume while listening to music.?? We spend zillions to achieve the best sound on components speaker etc,  power is pennies compared to what i spent on speakers.  Same with heat . So What.   Ive got 4 tons of ac so bust out the marshmellows.  ive never understood why people bring those up when what we are going for is sound.

Class A runs very hot and very inefficient , big watts in pure class A is big bucks

~~~~~~~~~
And when one's listening room is located in say Here in New Orleans, or Phoenix, or  South Florida, , the heat factor of a  class A amplifier is a  important consideration.
 The  Defy7 is like, I think Richard Gray says more like class B,  throws off  less that I had anticipated/with 12 tubes. 
, Richard also prefers Class A.
 But as you mention, Big Bucks. 
Did you say very inefficient?
Oh I see , requires plenty of power current = heat.
Glad the Defy is not class A. the heat  radiation would be too much to deal with in my 10x12 listening room. 

People with blood type A are always better than ones with blood type AB. What???? A nonsensical statement but assured to arouse a response.

Ralph - Let me know if you need a Beta tester, I can pay the freight both ways. My systems are visible in the virtual systems page. I appreciate your balance of the theory and practical application ( the hard work of design ) I also appreciate that you understand the ear / brain sensitivity to and preference for certain types / orders of distortion. A deep understanding of that can greatly inform the design objectives for any amplifier.
jim

Once again

You can prove this for your self by listening to an amp with user switchable bias while listening. EG Parasound JC1(low/high bias), Gryphon Antillion (low/high/higher bias) etc etc.

The difference you hear with more/higher Class-A bias, is an easier, smoother, richer presentation to the sound, that’s no less dynamic and yet makes the speakers disappear, even as the music goes louder. And as a result the sound washes over you rather than being fired at you from the drivers, and that is the result of the lessening of the class-B xover distortion when you engage more and more Class-A bias.

Cheers George

This statement is false.

You are false, and have no idea about the BS you spread sometimes, eg Zeroformers, OTL’s drive capabilities etc etc

Do your homework before posting this **** you spread.

I’ve built many Class-A’s from 20watters to 150watters, including massive 2 man lift self contained water cooled ones

Get off your horse, stop the BS and concentrate on your own "so called patented Class-D" I can link to on another forum, because it will be left behind and over taken with cheaper ones coming out the rate your going.

For the same given amp that is comfortable within all it’s design aspects either at 100w Class-A bias or at 5w Class-A, the 100w Class-A bias will ALWAYS!! sound better. Unless you are listening to 110db horns

Just to add to the end of that.
"Unless you are listening to >110db horns, then they will sound the same" because it only take 5w to get >110db horns going.

Cheers George

Wrong info to those reading this.
When listening at normal to loud levels "or" on hard to drive speakers,  Class-B xover distortion is just as prevalent in low bias Class-AB amps when pushed past the low Class-A bias point. And thats fact.
 
And I'll say it again.
For the same given amp that is comfortable within all it's design aspects either at 100w Class-A bias or at 5w Class-A, the 100w Class-A bias will ALWAYS!! sound better. unless you are listening to 110db horns
You can prove this for your self by listening to an amp with user switchable bias while listening. EG Parasound JC1 Gryphon Antillion etc etc.

Cheers George   

As no one in their right mind would prefer the sound of class-B xover distortion no matter how little.

There aren't any class B amps available in the consumer market, so this is no worries.

Anytime I see the word 'always' in statements like this..... next! 

yes I that was said before "I might be off here" and I replied to him.
Yes way off!!

And gave the explanations why.

https://forum.audiogon.com/posts/2130814

https://forum.audiogon.com/posts/2132377

As no one in their right mind would prefer the sound of class-B xover distortion no matter how little.
To the same amp in Class-A (unstressed) with no xover distortion.

The doubters, should do themselves and those here a favor and listen to a Gryphon Antillion that can be switched from 10w Class-A to 50w Class-A to 100w Class-A on the run while listening. And there are others like the Parasound JC1’s etc etc

Then the persistent doubters can hang their head in shame for even suggesting Class-B can sound better than Class-A if all is equal.

Cheers George

"I might be off here, but class A amps don’t drive lower impedance speakers very well either. Most class A amps aren’t stable into 2 ohm loads. Krell being one Of the exceptions."


Yes, you're way off. Ever hear of a well known audio company called Plinius?

Hmm, I don’t get it. When I owned a Plinius SA100 mkiii amp the difference from class A listening to A/B was like night and day. The amp of course does both Class A and Class A/B. It’s as if the lights were turned on. I’ve owned lots of Class A from Threshold T400, T200, Coda, Pass Labs, Plinius, and it wasn’t until I switched to tubes did I begin to here something different.


But SS Class A is as good as it gets to my ears. To those that can’t hear a difference I feel a bit sorry for you for you don’t know what you’re missing. Class A is where it’s at. Whomever suggested Class D was better than Class A suggests they’re in Audio training and haven’t had their training wheels removed.

Like I said, once again.

"There no such thing as a "good sounding" class-B xover distortion!"
Because Class-B xover distortion it’s NOT a "nice/colored" sounding distortion like many tubes give, and to eliminate if possible (without sterilizing the sound it with large amounts of feedback) is ALWAYS better than having it.

And those that continue to profess that a Class-B amps xover distortion can sound as good if not better than no xover distortion in Class-A amp are seriously kidding themselves, and worse are charlatans.

Cheers George

The sound of ANY amplifier is better without ANY distortions whatsoever. (Sure some distortions are not AS bad as others.)
So long as very little distortion is NOT attained by using means that create other problems areas EG: like masses of feedback global or local, global especially!

Of course, this being planet Earth, there are no amplifiers with no distortion.


Feedback is problematic in insufficient amounts- it can cause brightness and harshness as it introduces distortions of its own (mostly higher ordered harmonics). But if you are able to apply enough feedback then this phenomena does not occur. That amount seems to be north of 35dB. This also has to be consistent at all frequencies. Most amps have sufficient feedback at 100Hz (which is why they are usually measured at only 100Hz and not higher), but at 1KHz and 10KHz is where amps get into trouble. As a result most of the amps using feedback made in the last 60 years have increasing distortion as frequency goes up, because the amount of feedback is falling off, due to insufficient Gain Bandwidth Product.


This is why solid state in particular has gotten a reputation for being bright and harsh (and it does not matter what class of operation is being used) because the ear is very sensitive to those harmonics! This is literally why tube amps are still around since they can mask the higher ordered harmonics they make.

The sound of any amplifier is always about what distortion it makes

The sound of ANY amplifier is better without ANY distortions whatsoever. (Sure some distortions are not AS bad as others.)
So long as very little distortion is NOT attained by using means that create other problems areas EG: like masses of feedback global or local, global especially!
And there no such thing as "good" sounding class-B xover distortion!

So, with less than capable speakers and headphones class AB can sound better ?

It can sound better even with great speakers! The sound of any amplifier is always about what distortion it makes, and what distortion it doesn't. You can prevent crossover distortion in any AB circuit, since its a function of push-pull rather than whether its class A or not. The only exception is if the amp is operating class B but I don't know of a single example of a class B amp in high end audio.

So, with less than capable speakers and headphones class AB can sound better ? Even if we are talking about excellent class A amp ?

Who’s saying this rubbish, you get rid of transistor Class-B xover distortion when you bias higher into Class-A so long as everything else is unstressed.
Unless xover distortion is liked🤦‍♂️🤦‍♂️🤦‍♂️🤦‍♂️

Cheers George

No, this is not going green at all. I would personally compensate with other things, and others could too.
So, with less than capable speakers and headphones class AB can sound better ? Even if we are talking about excellent class A amp ?

You're not going to operate Class A on solar panels and it is the opposite of going green. What it can be when properly designed is a fabulous sound that's very involving, Hey folks all Class A aren't created equal, just like Class D or Class AB for that matter.

I recently added a Gustard X26 Pro to my Benchmark HPA4 | AHB2 mono. It replaced the Benchmark DAC3B (still keeping it). The sound of my system was transformed to that of the Gustard. The HPA4 and AHB2 do not seem to add any flavor.

It’s the ultimate chameleon. What the source puts in is exactly what the AHB2 dishes out. 

Class A amplifiers don’t always sound better. It depends on the headphones or speakers you’re using. Headphones and speakers with superior transient response (able to keep up with and resolve complex music) tend to sound better with Class A. But not all are made equal. This means you could have a Class A amp that performs worse than a Class AB - although, if designed well and without compromises, Class A is the gold standard.

This is a great resource:
https://circuitdigest.com/tutorial/classes-of-power-amplifier-explained

The only thing that matters to me is the interaction with the speaker I'm connecting it to. Over the years I always seem to gravitate back to class A. It's a finer more complete presentation to my ears. The whole notion of everything on audio being black and white across the board is what makes the used market ripe with choices.   

New Class Ds (e.g.NAD etc)..it's the future, like it or not. Have a listen, go on.I've had a range of A, A/B and early Ds over the last 50 years. Not going back away from D now - sound, size, heat, weight, WAF - all ticked.

Comparing company X’s class A amp with company B’s class AB amp may not mean much. I bet even there are many class D amps that sound better than class A amps at the same price point.
I cannot think of apple to apple comparison, but how about these?

• Between a class A amp with another class AB amp at the same price point: if you find a class AB amp sounds better than or equal to any class A amp at the same price, why would you go for class A?
• Between class A setting and class AB setting from the same amp: if class A setting does not sound any better than class AB setting, what’s the point for the extra cost of class A setting?

For my Plinius SA102, I cannot hear any difference between class A and AB settings in most music. Only when the music is very demanding (more bass and dynamics) I can tell some difference, but still the difference is not day and night difference.

Agree with the Benchmark stack being smooth, It is a smoothness that also has the most clarity that I ever heard.

I recently added a Gustard X26 Pro to my Benchmark HPA4 | AHB2 mono. It replaced the Benchmark DAC3B (still keeping it). The sound of my system was transformed to that of the Gustard. The HPA4 and AHB2 do not seem to add any flavor.

The Benchmark is as smooth or smoother than any class A amp I’ve heard...IF it’s paired with a good class A preamp. There is no point in owning a low distortion amplifier if the preamp is a weak link.

In my mind there are absolutely no reasons to own any other amp unless you either want a very colored sound or your speakers require more than 100/200 WPC, 8/4 ohm. You get an AHB2 then tailor the sound with your choice of preamp. Class A tube preamp paired with an AHB2 is that cliche “match made in heaven.”

https://youtu.be/abdmZbQPQtY
This guy has a very good channel, in one of the videos he talks about amp design and how many watts we really need, just bare in mind he is talking about European midsize room not US cathedrals 😜
I must say I totally agree with his viewpoint, when ever I go over 80db it starts to get seriously loud and often uncomfortable very soon.
Anyway, I thought his views on the matter would interest most audiophiles, also he has a very good way of presenting his views.
Enjoy!

@michaelc2020
If you are eve in the NYC area let me know  I can should you a pure 1 watt amp on a pair of Klipschorns that sound simple beautiful.

Happy Listening.

@audioman58That being said , inside the Quality of the parts have much more to do with the final result of the sound.

I would have normally agreed with your statement but last night hearing an OK to good parts preamp it was so close in sound to the better parts model we build I began to wonder if paying for custom transformers, resistors, capacitors, separate chassis, etc. was worth it.  So close it was confusing to us and made me think that we have now come full circle.  Still point-to-point wired and good parts but so close.

Happy Listening.   

Anyone in the NYC area - Northern NJ area who would like to hear the differences, send me a PM.  I would be more than happy to show you differences in equipment - Class A tube, Class A SS, Hybrid amplifiers, Direct Heated Triode components, etc.  I'll even supply the pizza.  Bring your amp if you like!

Happy Listening.  

Audio Research amps run A/B and top of the line ARC are the best I've heard. I'm sure there are better, but they are the best I've heard.

I think balanced and unbalanced is also significant because balanced interconnects are not affected by long runs.

Orpheus10, I don't have such a hearing as you imply, but my ear is quite sensitive to some aspects of a sound. 
Let's not transform this thread into tubes/transistors debate. Sure, ultimately tubes rule.
That's what we are trying to talk about - designs without compromises or almost without compromises. Heat, space, cost, look - this is all BS, just certain side effects. Done right it should always be full Class A design. And since Class A requires high level power supply, that's an additional advantage, that's where it all starts - with a power supply.

Lower power consumption with most A/B amplifier designs. They tend to be popular in devices like DACs. Due to the nature of the Class A topology, they are very inefficient with electricity and typically generate a lot of heat. My Class A systems can only be run once or twice a week...otherwise my power bill will go up! 

Class A has a conduction angle of 360 degrees, whereas A/B is less.

In theory, this should translate to a more controlled and linear amplification of the signal. In most cases, Class A amps have more of a "grip" on the signal and can be "straight wires with gain." Everyone hear probably knows what I mean (see what I did with that spelling mistake) lol 

yep. So class A is superior if it is designed well without compromises.

The Plinius amps of yesteryear allowed users to utilize an A or A/B button on the front of the amplifier to allow for Class A critical listening. The amp generally sounded its best in Class A, but A/B was very close.

I don't know if the current generation of Plinius amps allow for such user friendly options. 

Clarification on the above post; SS is OK for power amps; that's because tube power is very expensive when one needs a high powered amp, but tubes are still the ultimate. Here again is the question; can one actually hear "the ultimate".

Inna, I believe you to be quite sincere in your threads and posts which is why I'm responding now.

Whether it's class AB or A, or tubes or SS; the purpose of the equipment is to reproduce "music". As I previously stated, utilizing high quality parts, one would need the hearing of an "Irish Wolfhound" to tell the difference between A and AB. If you have it, fine, maybe it's worth the additional expense; I don't.

The reason for this post is to separate equipment lovers from music lovers. First, in order to qualify for that distinction, (The ability to separate the two) one must be an Audiophile with at least 30 years of experience, and I'll explain why that's  necessary.

In the beginning, we started with our favorite music on the radio. And then we advanced to our own fundamental rigs. They were SS rigs because tubes were too expensive. Those who are still into SS are there because they simply followed along that path to better SS without comparing that to tubes. Or, they decided tubes create distortion.

If you compare the reproduction of a 1K hertz tone, using SS and tubes; SS would win, but that's not music. Music has a certain "Essence" that can only be reproduced by tubes. People who are exclusively into SS are not even aware of that "Essence"; that's because they're not true music lovers. They buy music to hear their equipment, while music lovers buy equipment to hear their music.

Above link is wrong and was deleted this is the new one
https://forum.audiogon.com/discussions/stereophile-s-2021-products-of-the-year/post?postid=2135101#2...

Cheers George

Schiit Audio 20w Class-A Aegir stereo poweramp made it into the A rating in 2021 Stereophile’s Products of the Year.
https://forum.audiogon.com/discussions/stereophile-s-2012-products-of-the-year
Cheers George

"I don't think that liking good sound and liking good music are always in conflict."

Agreed

I average approx. 4 hours a day of listening to music through my system when life is "normal" for me. I have not been able to do that for the last couple months due to other priorities, but plan on getting back to it again soon. My amp is an AB (Magnus Audio MA400) & I love it. I've had class A's, other AB's, Triodes, Pentodes, SET's (both tube & SS), & class D. They all sound different & have their plus & minus's. This one connects best with me & my system.    

I like equipment that gives me good sound, other than that I only like tape decks. I don't think that liking good sound and liking good music are always in conflict. They can be but not necessarily so.
Old Levinson ML-2 class A amp is a dream piece.

The most difficult thing to discern is who listens to equipment, and who listens to music?

Ages ago when there were stereo stores all over the place, I fell in love with new speakers everyday. It's for certain I was an equipment lover then, but that's before I got into "The high end". My favorite tuner was "Sansui", it had a most beguiling sound that was quite soothing, and many people still prefer them to more accurate tuners.

My favorite speaker was first JBL, and next it was the Amazing Carver Speakers;
        https://www.stereophile.com/floorloudspeakers/290carver/index.html
The music had an other worldly quality; "ephemeral", I guess would be the one word description, but at one time I liked "reverb" in my car, that made your automobile sound like you were in a cave.

When I got into the high end, I finally discovered how good the music sounded unadorned without any tricks. Since most speakers have some kind of "sound", I had mine custom built to have no sound of their own, but to deliver the music, the same as a Class A amplifier delivers it to them; without anything added or subtracted from the music, only what the artist wanted you to hear, his music, with each and every individual nuance.

While I mentioned Class A because it is "Theoretically perfect", I can not audibly distinguish it from AB.

One of the problems of differentiating music lovers from equipment lovers, is that equipment lovers will almost never come clean and admit it (maybe they don't know themselves) consequently, right or wrong, I discern who is an equipment lover, and who is a music lover. This is very important when reading Posts.

Clearly, there are lovely examples of amps of all description. That said, I still occasionally hear old low watt Levinsen and Krell class A devices which move me to tears. There is something there. Options exist at my house but a Pass XA-30.5 remains an object of my most ardent affection.

Strange noboby is complaining about weight and dimensions of class A serious equipment.
I just gave away two clones of class A Pass Labs and I'm looking for a good traditional A/B amplifier, because I'm tired of turning on two blocks each time, having double waste of space (one block on floor and the other in the rack), having to move 38kg (83lbs) for each operation on every block for cables, cleaning floors, etc. The difference in sound is evident, as well as the inconvenience.
Just my experience.

Yet another fine example of a tempest in a teacup.

Hey, y'all.  Let's visit each others' homes and argue about the color selections of wall paint, furnishings, each others' shoes....

...that dumb aze Porsche vs. a nice Cadillac SUV.....with all the options...

The latter strikes me as the most blatant offering of a pointless ego toy that will NEVER see muddy roads....perhaps a deep puddle @ the mall....the bumpy RR Xing that gets 'tippy-toed' over...

Give it a break....:(