ATI Battle Class AB vs Class D Amplifier Shootout

[Irvrobinson]

Me too, in fact if waf was not a factor, I would have pulled the trigger just for the sake of owning one amp that has seemingly the lowest distortions money can buy.

As soon as the ABH2 was released I was tempted by it, mainly because it is so small and runs so cool (and has awesome specs). But I'm not convinced ~200 watts/ch into 4 ohms is enough for the Salon2s in my >8000cuft room in the bass, so I'd probably be talking about a pair of bridged amplifiers, so I'd be dropping $6K on a pair. Of course, what I would mostly likely do is just order one, play some Telarc classic bass show-off CDs (1812 Overture, Bach Toccata and Fugue in D minor) and see if it clips, and if it does, order the second one.

I'm also very skeptical that it would sound detectably better than my current AT3000 amp.

And then there's the marketing statements on their website. Calling amplifiers "the weakest link". Uh huh.

 

[Verdinut]

And then there's the marketing statements on their website. Calling amplifiers "the weakest link". Uh huh.

What a marketing bullshit again to attract more buyers and make them spend more money!

 

[Out-Of-Phase]

What a marketing bullshit again to attract more buyers and make them spend more money!

"new...."
"revolutionary...."
"extraordinary...."
"giant-killer...."
"high-resolution...."
"radically different...."
"radical...."
"ultimate...."
"emotion...."
"game-changer...."
"head and shoulders above the competition...."
"overlooked nuances, dynamics, and detail...."

"No other audio amplifier comes close to delivering the clean, quiet, and robust power of the AHB2."

"Power amplifiers are a weak link in most audio systems."

"Benchmark has raised the bar by introducing a new and revolutionary amplifier!"

The Barnum & Bailey Audiophile Circus - The Greatest Show on Earth! - Don't miss it!

 

[PENG]

As soon as the ABH2 was released I was tempted by it, mainly because it is so small and runs so cool (and has awesome specs). But I'm not convinced ~200 watts/ch into 4 ohms is enough for the Salon2s in my >8000cuft room in the bass, so I'd probably be talking about a pair of bridged amplifiers, so I'd be dropping $6K on a pair. Of course, what I would mostly likely do is just order one, play some Telarc classic bass show-off CDs (1812 Overture, Bach Toccata and Fugue in D minor) and see if it clips, and if it does, order the second one.

I'm also very skeptical that it would sound detectably better than my current AT3000 amp.

And then there's the marketing statements on their website. Calling amplifiers "the weakest link". Uh huh.

Yep, it is practically a $6000 amp if you have large 4 ohms speakers with sensitivity below 93 dB/2.83v/1m. Not only it is limited to 100 W 8 ohms, it's fantastic distortions also shot up rapidly from a touch over 100 W.

 

[PENG]

What a marketing bullshit again to attract more buyers and make them spend more money!

Most real engineers wouldn't do that even if they are VP sales/marketing, what a pity.., otherwise there are lots of good information on that website.

 

[Irvrobinson]

Not only it is limited to 100 W 8 ohms, it's fantastic distortions also shot up rapidly from a touch over 100 W.

Good point. But it's size and specs tempt me. Of course, with RichB offering to ship me his Hypex-based ATI class D amp for comparison, that would be another alternative should I decide to switch out the AT3000. If the AT3000 breaks again that'll probably push me into a change.

 

[PLE]

This post is so dumb I should ignore it, but I can't resist asking you to explain these silly statements.

Exactly what do you think, electrically, happens in a push-pull output transistor pair? What does "pushing" and "pulling" electrically consist of? Extra credit question - does a push-pull amplifier have a phase splitter prior to the gain stage?

Having a Bad day? I guess you couldn't resist neither using these rude words right? Your question is not clear, but I can try. what happens electrically? You mean to explain how a transistor amplify a small signal? It would take many pages to explain the behavior of semi conductors, not sure what you mean by that. an audio signal has a negative part and a positive part and yes there is a phase splitter at the front, this is correct, but that is simply not what defines the class of operation. Class D amps with differential inputs are common, they are not push pull. And yes historically there was a connection between class A operation and a "Single ended triode" but it's not the only way to achieve Class A these days. I'm open to debate this but not if you will be using the dumb word, and yes I'm an electronic engineer working in audio development.

 

[Irvrobinson]

Having a Bad day? I guess you couldn't resist neither using these rude words right? Your question is not clear, but I can try. what happens electrically? You mean to explain how a transistor amplify a small signal? It would take many pages to explain the behavior of semi conductors, not sure what you mean by that. an audio signal has a negative part and a positive part and yes there is a phase splitter at the front, this is correct, but that is simply not what defines the class of operation. Class D amps with differential inputs are common, they are not push pull. And yes historically there was a connection between class A operation and a "Single ended triode" but it's not the only way to achieve Class A these days. I'm open to debate this but not if you will be using the dumb word, and yes I'm an electronic engineer working in audio development.

I never said that output stage topology had anything to do with the class of operation.

Now you've completely convinced me I should ignore you.

 

[PENG]

Having a Bad day? I guess you couldn't resist neither using these rude words right? Your question is not clear, but I can try. what happens electrically? You mean to explain how a transistor amplify a small signal? It would take many pages to explain the behavior of semi conductors, not sure what you mean by that. an audio signal has a negative part and a positive part and yes there is a phase splitter at the front, this is correct, but that is simply not what defines the class of operation. Class D amps with differential inputs are common, they are not push pull. And yes historically there was a connection between class A operation and a "Single ended triode" but it's not the only way to achieve Class A these days. I'm open to debate this but not if you will be using the dumb word, and yes I'm an electronic engineer working in audio development.

I don't doubt you know something, or a lot about audio electronics but if I am not mistaken, your post#118 seems to reference @Irvrobinson 's post#102 that obviously was written to point out the incorrect information presented in @Verdinut 's post#101. Knowing Verdinut I am sure he does not have issue with anyone letting him know of an error in his post. If you read both posts #101 and 102 again carefully you will (hope so anyway) know what I am trying to say.

 

[PLE]

I never said that output stage topology had anything to do with the class of operation.

Now you've completely convinced me I should ignore you.

Please do Mr Robinson, I don't even know anymore what you are arguing about, the only thing I disagreed about what you've put forward was when you said: "Differential (sometimes called push-pull)" that's all I was trying to say, differential and push pull are 2 different concepts, and you can't call differential push pull, no need to get upset... Bye now

 

[Andrein]

Please do Mr Robinson, I don't even know anymore what you are arguing about, the only thing I disagreed about what you've put forward was when you said: "Differential (sometimes called push-pull)" that's all I was trying to say, differential and push pull are 2 different concepts, and you can't call differential push pull, no need to get upset... Bye now

I bet he does not know himself...

 

[AcuDefTechGuy]

"new...."
"revolutionary...."
"extraordinary...."
"giant-killer...."
"high-resolution...."
"radically different...."
"radical...."
"ultimate...."
"emotion...."
"game-changer...."
"head and shoulders above the competition...."
"overlooked nuances, dynamics, and detail...."

"No other audio amplifier comes close to delivering the clean, quiet, and robust power of the AHB2."

"Power amplifiers are a weak link in most audio systems."

"Benchmark has raised the bar by introducing a new and revolutionary amplifier!"

The Barnum & Bailey Audiophile Circus - The Greatest Show on Earth! - Don't miss it!

As my little daughter would say, “Exaggeration much?” Haha.

 

[AcuDefTechGuy]

If the AT3000 breaks again that'll probably push me into a change.

Oh, I must have missed this. I didn’t know it broke once already?

 

[Irvrobinson]

Please do Mr Robinson, I don't even know anymore what you are arguing about, the only thing I disagreed about what you've put forward was when you said: "Differential (sometimes called push-pull)" that's all I was trying to say, differential and push pull are 2 different concepts, and you can't call differential push pull, no need to get upset... Bye now

You are being obtuse. They are two different concepts, but all push-pull output stages are electrically differential. At least in the US, push-pull output stages are usually just called "differential". That's why they have phase splitters before the output stage when the line-level inputs are single-ended; each of the two transistors in the pair are fed with only 180 degrees of a wave's duration. If the the amplifier has a differential signal path from the inputs to the output stage, no phase-splitter is required for that path.

 

[Irvrobinson]

Oh, I must have missed this. I didn’t know it broke once already?

One channel module of the five had multiple capacitors fail, and a power supply fuse blow. ATI repaired the failed channel module at no cost to me except for shipping it to them. Since I was only using four of the five channels anyway, I haven't even reinstalled it.

 

[PLE]

You are being obtuse. They are two different concepts, but all push-pull output stages are electrically differential. At least in the US, push-pull output stages are usually just called "differential". That's why they have phase splitters before the output stage when the line-level inputs are single-ended; each of the two transistors in the pair are fed with only 180 degrees of a wave's duration. If the the amplifier has a differential signal path from the inputs to the output stage, no phase-splitter is required for that path.

It was not to be obtuse, just that clarity matters when discussing science... there are many applications to differential signals, this is one of them. You also know that in a push pull configuration the pair is not necessarily fed wit "only 180 degrees" It can and it should be more than that to avoid excessive crossover distortion. A "phase splitter" has no electronic meaning but I'll give you that I understand what you mean. There are many ways to bias the transistor to achieve their operation in the proper phase but I'll let this one go. You are right that a push pull amp has a differential output by design. I apologize if I was not used to this terminology and semantics, maybe it is a language and vocabulary difference and I don't doubt that you understand how it works. Where I'm from the "usual" meaning of a differential pair is not a signal splitted between in it's two phases, but rather the same signal, one having it's phase reversed, that's the "most" common use of the term differential, to me, but I see where you come from
Peace

 

[Erod]

Two cents from a non-engineer who wouldn't even think to wade into a debate on the physics involved with these amps.

Full disclosure, I have two separate A/B amps driving my 11 channels with D amps inside both my subs. As long as these continue to do the job, I'm staying put. 225 watts into the front 5 channels with 125 watts into the backs and overheads. 400 and 185, respectively, for 4 ohms. I'm set.

I don't have anything inherently against Class D amps. Sounds like they have made huge strides and are performing at or near A/B amp ability, and my ears probably couldn't tell the difference. That's awesome, and if my amps started to fail, I would absolutely consider them. Especially as we all get older, lugging around those A/B amps is tedious, and an equal performer at 25 pounds gets more and more attractive.

However, I do tend to be turned off by this cult-like militancy of many Class D proponents in my experiences.

Say one semi-disparaging word in any setting online, and they come raining down on you like an Antifa rally in Portland. Imbalanced and petulant. Completely pissed that anyone would have the nerve to use an A/B amp with less efficiency, let alone make a claim that they sound better than D.

Frankly, it makes me want to give my amps a big ole bear hug.

 

[AcuDefTechGuy]

I do tend to be turned off by this cult-like militancy of many Class D proponents in my experiences.

Say one semi-disparaging word in any setting online, and they come raining down on you like an Antifa rally in Portland. Imbalanced and petulant. Completely pissed that anyone would have the nerve to use an A/B amp with less efficiency, let alone make a claim that they sound better than D.

1. If you were to do a poll on AH, I bet most guys here own class A/B amps. I think class-D amp owners are in the minority on AH.

2. Not all Class-D amps are created equal. For example, when we look at the SNR, Crosstalk, FR, etc., specs, of the ATI class-D amps versus the class-D pro amps (Yamaha, Crown, QSC, etc.),we can see a big difference at least in the measurements and specs.

Until I saw the specs of the ATI class-D amps (SNR 123dB, Crosstalk 100dB, Damping Factor 5,000, Slew Rate > 60 V/microsec, THD 0.02%, etc.) , I thought that all Class-D amps were incapable of the same specs as the audiophile class-A/B amps.

The class-D ATI amps specs are actually better than some of the class-A/B ATI amps, which are already great.

Damping factor of 5,000 vs 400? Man I need to use these ATI class-D amps to power my 10 passive subwoofers.

 

[Out-Of-Phase]

Two cents from a non-engineer who wouldn't even think to wade into a debate on the physics involved with these amps.

Full disclosure, I have two separate A/B amps driving my 11 channels with D amps inside both my subs. As long as these continue to do the job, I'm staying put. 225 watts into the front 5 channels with 125 watts into the backs and overheads. 400 and 185, respectively, for 4 ohms. I'm set.

I don't have anything inherently against Class D amps. Sounds like they have made huge strides and are performing at or near A/B amp ability, and my ears probably couldn't tell the difference. That's awesome, and if my amps started to fail, I would absolutely consider them. Especially as we all get older, lugging around those A/B amps is tedious, and an equal performer at 25 pounds gets more and more attractive.

However, I do tend to be turned off by this cult-like militancy of many Class D proponents in my experiences.

Say one semi-disparaging word in any setting online, and they come raining down on you like an Antifa rally in Portland. Imbalanced and petulant. Completely pissed that anyone would have the nerve to use an A/B amp with less efficiency, let alone make a claim that they sound better than D.

Frankly, it makes me want to give my amps a big ole bear hug.

I've never run into that. For me, it's been just the opposite. Especially audiophiles.

"Say one semi-disparaging word in any setting online, and they come raining down on you like an Antifa rally in Portland. Imbalanced and petulant."

Who's they?

 

[lovinthehd]

I've never run into that. For me, it's been just the opposite. Especially audiophiles.

"Say one semi-disparaging word in any setting online, and they come raining down on you like an Antifa rally in Portland. Imbalanced and petulant."

Who's they?

LOL obviously those darn lefties. Yet it is the conservative/audiophile seemingly who gets panties in a bunch just from being challenged.