Adam S3a Class AB Vs Class D Amps???

[kingofswing]

Hi people,

I would like Adam users to comment on thier experiences with the two types of amps.

All i know is that the older class AB amps were 100 watts and the new class D amps are 150 watts.

I also know that the class D amps have no heat sinks like the s3a's do, and also that the class d amps keep cooler than the AB.

What i would like to know from users, is how they feel about the two amps...

how do they differ sound wise? Is the change for the better? Which versions of the s3a's do most users own?

cheers in advance.

[Solunaris]

I had the old ones and got the new ones. Can't really tell the difference between the two amps in sound. I just like that there's no heat sink.

[DaveH]

Have S3As here.

I ask the question awhile back:
How can you tell one version from another?
Never got an answer.

If external heatsink is the clue I must have the AB amps.

Does anyone know why the change was made?

So to answer at least one of your questions:

I believe I have the class AB amps.
But I have never heard both types side by side.

[lordmiguel]

hmmm, i have heatsinks and 150W amps. so does the pair reviewed in '04 in sound on sound. confuzzzed.

[Bryce]

Originally Posted by kingofswing

All i know is that the older class AB amps were 100 watts and the new class D amps are 150 watts.

I believe the older Class A/B amps were 150 W, and the new ICE Power amps are 250 W.

dB
ADAM Audio USA

[kingofswing]

Originally Posted by Bryce

I believe the older Class A/B amps were 150 W, and the new ICE Power amps are 250 W.

dB
ADAM Audio USA

Maybe i got my facts wrong. But im sure i read somewhere that the older amps were 100 watters. oh well.

Bryce, what are the sonic differences between the two amps? Are the class AB amps the better option over the new ones?

im asking because im about to upgrade from my p33's. I just dont wanna shoot myself on the foot by making the wrong choice.

[Killahurts]

Originally Posted by Bryce

I believe the older Class A/B amps were 150 W, and the new ICE Power amps are 250 W.

dB
ADAM Audio USA

250 W ?

You mean in each amp?

So each S3A has 750 Watts?

[aapee]

Originally Posted by kingofswing

Maybe i got my facts wrong. But im sure i read somewhere that the older amps were 100 watters. oh well.

Bryce, what are the sonic differences between the two amps? Are the class AB amps the better option over the new ones?

im asking because im about to upgrade from my p33's. I just dont wanna shoot myself on the foot by making the wrong choice.

Wait till I go home. I got mail from ADAM audio concerning these amps... Tonight I will post an answer.

AaPee

[Bryce]

Originally Posted by kingofswing

Maybe i got my facts wrong. But im sure i read somewhere that the older amps were 100 watters. oh well.

The reeason for your confusion is that there have actually been three generations of S3As...the first ones had 100W TDA chip amps, the second ones (the ones that most folks have ) were the 150W Class A/B discretes. The current batch has the 250W ICE power amps.

Mine actually have the old TDA chips. I haven't felt the need to change them...

Bryce, what are the sonic differences between the two amps? Are the class AB amps the better option over the new ones?

Better is relative, of course.

Sonically, the ICE power amps sound very much like the Class A/B discretes - we took a long time choosing the new amps specifically because we didn't want to change the sound of the S series. We've found that we can put one Class A/B on one side and one ICE power on the other side, and (unless you know you're supposed to be looking for something) it's very difficult to tell that something is not what it should be.

Originally Posted by Killahurts

250 W ?

You mean in each amp?

So each S3A has 750 Watts?

Well, each one currently has 3 x 250W, yes...

As I understand it, that doss not mean that they combine to produce 750W - but then again, I'm not the world's most technical guy when it comes to power amps and their applications, so I could be wrong...

dB
ADAM Audio USA

Originally Posted by DaveH

Have S3As here.

If external heatsink is the clue I must have the AB amps.

Does anyone know why the change was made?

Well for one thing, Class AB is sonically more pure than Class D.

And the only reason I can think of for the switch between Class AB and then to D is profit margin for the company. Class D is very cheap to produce, also notice it does not need a big extruded aluminum heat sink. But Class D will take a shit on you eventually, just a matter of time. There basically switching power supplies but utilize pulse width modulation so as to be able to reproduce and amplify an alternating current. There ok for subwoofers, but I honestly think thats ridiculous to use a class D amplifier in a high end studio monitor.

[Rufuss Sewell]

Originally Posted by Bryce

As I understand it, that doss not mean that they combine to produce 750W - but then again, I'm not the world's most technical guy when it comes to power amps and their applications, so I could be wrong...

dB
ADAM Audio USA

I am VERY ignorant when it comes to electronics, so I'm probably misunderstanding the concept. But I was under the impression that a watt is measure of how much power a unit uses over a period of time. A kilowatt hour and so forth. This is how the electric company bills you for consumption. Therefore if each speaker has 3x 250 watt amps, it is indeed using 750 watts per speaker.

That's not a measurement of amplitude like db's, just a measurement of power consumption per unit. If you have 2x s3a's you are using 1500 watts to power your speakers. If you are using the s3a's for 5.1 then it's 3750 watts plus a sub. That's like having 62x 60 watt lightbulbs on. No wonder my electricity bill is so high.

Not that I have 5x s3a's... just 2x s2.5a's.

It would seem to me that ADAM has replaced the more efficient 150 watt amps with less efficient 250 watt amps that, as Bryce said, sound the same. They just result in a higher energy bill. I'd stick to the AB 150 watt amps.

[ghellquist]

Originally Posted by Rufuss Sewell

I am VERY ignorant when it comes to electronics, so I'm probably misunderstanding the concept. But I was under the impression that a watt is measure of how much power a unit uses over a period of time. A kilowatt hour and so forth. This is how the electric company bills you for consumption. Therefore if each speaker has 3x 250 watt amps, it is indeed using 750 watts per speaker.

Not quite right.

Typically power amps are measured on how much they can OUTPUT to the speaker. (sorry for the capital letters).
- a 150 W can output that much
- a 250 W can output more and could create a stronger sound, possibly.

What that measurement does not say is how much the the amplifier requires as INPUT. Typically a class A/B amp takes in quite a bit more power than is output. The rest goes away as heat. Hence the heat sink. A D-class amplifier is generally much more efficient, much less is wasted as heat and they may live quite happily without a heat sink.

So in effect at the same loudness level (ie same wattage to the speaker) the D-class amplifier draws less input power and creates less heat.

G.

[ghellquist]

Originally Posted by WHITEAUDIOLABs

Well for one thing, Class AB is sonically more pure than Class D.

And the only reason I can think of for the switch between Class AB and then to D is profit margin for the company. Class D is very cheap to produce, also notice it does not need a big extruded aluminum heat sink. But Class D will take a shit on you eventually, just a matter of time. There basically switching power supplies but utilize pulse width modulation so as to be able to reproduce and amplify an alternating current. There ok for subwoofers, but I honestly think thats ridiculous to use a class D amplifier in a high end studio monitor.

Well, I think you should stick to tube amplifiers and stay away from everything solid state. After all "everyone" (never met him in person though) knows that tubes are far superior in every respect to solid state.

Now, if you have carefully in a blind test evaluated the AB version against the D version and was able to select it more than 8 times out of 10 and thought the sound to be much worse then you will have no problem in knowing what to select.

For the rest of us, if it sounds good it is good.

Gunnar

[Bryce]

Originally Posted by WHITEAUDIOLABs

There ok for subwoofers, but I honestly think thats ridiculous to use a class D amplifier in a high end studio monitor.

That may have been true at one point, but Class D technology has way improved since it was introduced (over 20 years ago, I believe).

There are a bunch of folks using switching amps right now. For example, ICE power amps (I don't know if it's the same ones we use) are also used by Focal and Dynaudio.

We've been pretty lucky to have developed a pretty good reputation - it'd be kind of silly for us to risk compromising it by using a crappy sounding amp.

dB
ADAM Audio USA

[kingofswing]

Originally Posted by Bryce

That may have been true at one point, but Class D technology has way improved since it was introduced (over 20 years ago, I believe).

There are a bunch of folks using switching amps right now. For example, ICE power amps (I don't know if it's the same ones we use) are also used by Focal and Dynaudio.

We've been pretty lucky to have developed a pretty good reputation - it'd be kind of silly for us to risk compromising it by using a crappy sounding amp.

dB
ADAM Audio USA

thats right, but it seems that Focal use the the Class D amps for the bass driver and class AB for the tweeter.

[makoto]

"the first ones had 100W TDA chip amps, the second ones (the ones that most folks have ) were the 150W Class A/B discretes."

Is there an absolute way to determine what model I have, s/n cut off #, physical indications, etc?

Thanks,

Makoto

[Bryce]

Originally Posted by kingofswing

thats right, but it seems that Focal use the the Class D amps for the bass driver and class AB for the tweeter.

Depends on the model. I believe the SM11 uses the ICE power amps for the midrange driver as well.

Originally Posted by makoto

"the first ones had 100W TDA chip amps, the second ones (the ones that most folks have ) were the 150W Class A/B discretes."

Is there an absolute way to determine what model I have, s/n cut off #, physical indications, etc?

The heat sink is the key. I forget the exact cutoff, but IIRC anything under P4000 without a heat sink is a TDA unit.

dB
ADAM Audio USA

[kingofswing]

Originally Posted by Bryce

Depends on the model. I believe the SM11 uses the ICE power amps for the midrange driver as well.

The heat sink is the key. I forget the exact cutoff, but IIRC anything under P4000 without a heat sink is a TDA unit.

dB
ADAM Audio USA

looks like your right about the midrange amps Bryce. this is what i picked up from focals website on their flagship model.


'the SM11 uses class "D" power stages for low and mid-frequencies channels to allow high power together with the purest sound quality.

the SM11 utilises two class-D power stages, one for the woofer amplification and one for the midrange. But only two years ago, this would not have been compatible with the performance level demanded by a high-end monitoring system such as the SM11.

Class-D amplifiers achieve very high efficiency (typically over 90%, compared to -at most- 65% fot conventional amplification stages) by using a high frequency switching scheme of the output transistors, with those operating only in two extreme states: "full speed" or "zero speed".

The benefit being that in either of these two states the losses in the transistors (generating heat) is minimal. Since the theory has been introduced, the penalty has for long been a high level of distortion, making it unsuitable for high quality audio.

The breakthrough only occurred a couple of years ago, and the class-D modules used in the SM11 (under patent by a third party) can match or exceed the performance, both sonically and on objective tests, of the best conventional designs. Having said that, the best class-D stages still suffer from some bandwidth limitation inherent to the switching frequency: to put it simply they can cope well up to 20kHz, but no so well beyond. Hence the choice, on the SM11, of a conventional, high quality, class AB power stage for the high frequency channel, allowing extended bandwitdh at the expense of lower efficiency: but this was a rational choice knowing that the effective r.m.s. power dissipated on this channel is relatively small when compared to those of the woofer and midrange'.

[Bryce]

the class-D modules used in the SM11 (under patent by a third party) can match or exceed the performance, both sonically and on objective tests, of the best conventional designs.

That's my understanding as well....

Having said that, the best class-D stages still suffer from some bandwidth limitation inherent to the switching frequency: to put it simply they can cope well up to 20kHz, but no so well beyond.

We disagree.

The ADAMs go quite a bit above 20kHz, and our tests have revealed no such limitations...or we wouldn't have used the ICE power amps.

As I mentioned earlier - it'd be somewhat short-sighted for us to have put inferior amps into our top of the line products (especially driving the folded ribbons that put us on the map) just to save a few dollars.

dB
ADAM Audio USA

Originally Posted by ghellquist

Well, I think you should stick to tube amplifiers and stay away from everything solid state. After all "everyone" (never met him in person though) knows that tubes are far superior in every respect to solid state.

Now, if you have carefully in a blind test evaluated the AB version against the D version and was able to select it more than 8 times out of 10 and thought the sound to be much worse then you will have no problem in knowing what to select.

For the rest of us, if it sounds good it is good.

Gunnar

Ah man, I can't have anything to do with solid state. That sucks donkey dick.
Tubes really are not "Far Superior" to semiconductors. You like how tube equipment sounds, and most goobers call it "Warmth or Tone" which is a good way to describe it I guess, but what you really are hearing that you like are harmonics. Plain n' simple.

Well another good thing about your 'all' tube gear with no silicon components in it, though Im sure no one has a piece of studio gear which meets that qualification. Is that it could withstand a nuclear war. the electro-magnetic pulse will not destroy tubes, but is will sure as shit kill anything considered solid state, no questions asked.

That is the one reason why the U.S. Military still wharehouses the largest collection of tube configured communications equipment in the world. The only ******** thing is, after a hail mary tit for tat greats dragoon, is the ionosphere will be so horribly ionized that radio waves would have a better chance of propagating through the earths molten core than through the atmosphere.

But back to what you were doubting. Class D does suck, I mean sure, a company can dress the turd up like a hot dog if they want, but after you eat it, it's still going to be a turd.

You pay a price for efficiency. High efficiency, low something else. You can decide.

But hey all that really matters is that it looks pretty........ Right... Right..



^^^^That was a good burn. You have to give me credit for that.^^^^

[sysexguy]

in the hopefully unlikely event of a nuclear war, having Ice powered monitors may not be my greatest concern.

Comparing the B&O Ice power amps to class D car audio from the early nineties is not a fair, accurate or scientific comparison in any way.

Btw, we've done some extensive listening with all three generations of S*A amps and the hifi Adams using everything from Vtl and McIntosh through Jeff Rowland amps (which coincidentally, are ICE power as well) and the new ADAM Ice power amps sound just fine.

my $0.02

Andy

[synthetic]

Raise your hand if you've A/Bed ADAM monitors with both amps installed.

[kingofswing]

Originally Posted by synthetic

Raise your hand if you've A/Bed ADAM monitors with both amps installed.

I have demoed the S3a's with the class AB amps (not the new ones), but also own a pair of P33a's with the new class D amps (impressive for the money).

But i cannot compared the above models, not like for like.

[Solunaris]

I think the new class D power amps sound better. Just a little tighter and crisper. Not as loose. It's a very miniscule difference at best.

[kingofswing]

Originally Posted by arrogantbastard

I think the new class D power amps sound better. Just a little tighter and crisper. Not as loose. It's a very miniscule difference at best.

If you dont mind me asking, which Adam speakers do you use / own?

[aapee]

Originally Posted by synthetic

Raise your hand if you've A/Bed ADAM monitors with both amps installed.

Me too.

But they were P11A's. First I got P11A's with AB for demo use. I used them for a week and liked them. Then I got D amped ones and kept them. Just matter of taste...

AaPee

[Golden Ears]

I'm also wondering about this.... I did a/b the A7 vs the A7x and am currently looking for some A7's. I found I preferred the sound of the A7 and felt that the additional db of the A7x was not worth the trade off in price or sound. If I were using them as DJ monitors ONLY I might go for the A7x..but realistically they would not be loud enough for most sound booths and I would need another model.

It wasn't a great comparison bewteen them (different rooms but same music- but I paid close attention to the sound nearfield) - I have a very good memory for sound, and was looking forward to the A7x and its increased power. I also used to work for Bang and Olufsen, and to me I can clearly hear the issues of some ICE power amps and their limitiations. I worked for B & O from 2005- 2007. I listened to the Beolab 3's and the Beolab 5's (now $23,000 per pair) all day long. I could also easily hear the HF of one of their older models the BeoLab 1 was cleaner with less grit and more air and smoothness on upper piano the Beolab 1 unit has A/B for the top and ICE power (class D) for the low frequencies. I do not know what Jeff Rowland is doing with ICE - but I have wanted a pair of his Model 7 Amplifiers (class A) for years. I have not gone through the trouble to listen to his ICE powered amp- but if anyone could get Class D full range right... its likely Jeff. Bang and Olufsen simply missed the mark. Bang and Olufsen still makes a hybrid in the BeoLab 9- a model recently released, and the fact that they decided to make it a hybrid A/B top and Ice bottom instead of all ICE power is worth investigating.

There is an instance where class D was more musical and superior to anything else I have heard... Damian Martin (formerly of Spectral and Entec, now with Constellation Audio) had designed subwoofers for Entec using class D. They IMHO were the most musical sounding Subs I have ever heard. Its a pity that company is now defunct. The subs worked form 100hz down and have 500 watts of class D amplification and were servo controlled. Martin - however , is a skilled guy with amplification, more so than the Pro industry- and if anyone at the time could make class D sound good.. it was him. I was completely fooled by the Class D in his subwoofers and hadn't a clue that it wasn't class A/B- it was a turning point for me in accepting Class D as viable if used properly.

So I have heard class D sound exceptionally good- though it was an old 1980's- 1990's design that was restricted LF. So if you are personally historically adverse to buying class D - you may want to check the crossover frequency of hybrid speakers to make sure the Class D is operating at low frequencies only (check the crossover slopes too). Moore's Law states everything gets faster- so switching technology should get quicker..... but I am not an engineer to determine if faster switching is directly proportional to less audible switching distortion- or even if we are measuring the right kind of audible distortion or can measure it with current gear.. I am sure we remember cheap Japanese 1970's solid state that tested really really well but sounded dreadful.

It helps to know what your are listening for when selecting speakers with particular technologies... for instance metal dome tweeters may ring, electrostats may have bass issues and beaming, multi way systems with differing drivers may have lobing issues, two ways can suffer from compression...etc.etc.etc....

If "YOU" can't tell the difference.... personally between A/B and ICE then logic might dictate it will unlikely affect your mixes (but what you hear and what others hear may be different YMMV). If you can hear the difference- then likely one will be superior to the other depending on how your mixes translate. More and More OEM car Audio uses class D so if you were mixing hip hop, class D might be a good choice to negate pumping up any negative sound that might be amplified by people boosting the treble in their cars and increasing the likelihood of hearing Class D distortion artifacts and harmonics. (You might be able hear that with class D amplified monitors)

If you were mixing classical music, or piano string or woodwinds, and could hear the difference between class D and A/B perhaps you should look at A/B designs - as more of your mixes would be played back on class A/B amps (few homes systems are Class D and would suffer from Class D issues and so you want to maximize your sound for class A/B).

Hint: Try a extreme in car treble boost with a class D based car system (as many car owners tend to do- there are many ICE powered cars as Bang and Olufsen is the OEM now for many autos- see their website) after your mix and see how that translates....does it get flat and gritty?

I hope this makes some sort of logical sense to people. Please don't think I am an expert on this- as I am not a professional sound engineer like Bryce I jsut remix for myself for fun and am an extreme audiophile that likes full range true to life sounding systems- not an audiophile that likes unrealistically bass light systems with a BBC Midrange suckout.

[Golden Ears]

Originally Posted by makoto

"the first ones had 100W TDA chip amps, the second ones (the ones that most folks have ) were the 150W Class A/B discretes."

Is there an absolute way to determine what model I have, s/n cut off #, physical indications, etc?

Thanks,

Makoto

I'd like to know for the s3a's...

[Golden Ears]

Originally Posted by Rufuss Sewell

I am VERY ignorant when it comes to electronics, so I'm probably misunderstanding the concept. But I was under the impression that a watt is measure of how much power a unit uses over a period of time. A kilowatt hour and so forth. This is how the electric company bills you for consumption. Therefore if each speaker has 3x 250 watt amps, it is indeed using 750 watts per speaker.

That's not a measurement of amplitude like db's, just a measurement of power consumption per unit. If you have 2x s3a's you are using 1500 watts to power your speakers. If you are using the s3a's for 5.1 then it's 3750 watts plus a sub. That's like having 62x 60 watt lightbulbs on. No wonder my electricity bill is so high.

Not that I have 5x s3a's... just 2x s2.5a's.

It would seem to me that ADAM has replaced the more efficient 150 watt amps with less efficient 250 watt amps that, as Bryce said, sound the same. They just result in a higher energy bill. I'd stick to the AB 150 watt amps.

FWIW At idle the Ice would use a lot less power.