Review: Acoustic Imagery Atsah Power Amplifiers ...

joeinid

joeinid

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Has anyone heard these amps?

The reviewer bought them. I like his reviews and wonder how good these N-core amps really sound.

Acoustic Imagery Atsah Power Amplifiers | 10 Audio

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They probably sound the same as any Ncore 1200 based amp out there.

Personally, I think I would go with the Theta Prometheus monos, as they look better and will be easier to resale down the road. Thay also come with a linear PSU, which may upset the rest of your system less than a switcher.
 
Elberoth said:
They probably sound the same as any Ncore 1200 based amp out there.

Personally, I think I would go with the Theta Prometheus monos, as they look better and will be easier to resale down the road. Thay also come with a linear PSU, which may upset the rest of your system less than a switcher.
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Adam, I just finished reading Stereophile's review of the Theta Promethius. He is recommending that it be placed in their Class A ratings. Sounds like someone has figured how to make the N core sound great.

And JA said they measured "Superb" in his tests. That's something that most Class D amps can't do.
 
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I'm surprised that NC400 and NC1200 based amps aren't much cheaper than what people are charging. Even though NC1200 modules are only supposed to be sold to manufacturers, brand new ones do show up on Ebay and sell for around $700 the pair with their SMPSs. Building a Class D amp using the assembled SMPS and the NC400/NC1200 modules takes about the same or less skill as assembling a computer from all the parts. Actually, assembling a computer from scratch and loading all of the software is much more complex. There is simply not much to a Ncore based Class D amp. Of course what we are seeing now is manufacturers machining their chassis from billet aluminum so you have a $1000 amp with a $6000 chassis that sells for many multiples of that number. The new Theta Class D amps are a bargain by comparison and they have linear power supplies to boot.
 
Elberoth said:
They probably sound the same as any Ncore 1200 based amp out there.

Personally, I think I would go with the Theta Prometheus monos, as they look better and will be easier to resale down the road. Thay also come with a linear PSU, which may upset the rest of your system less than a switcher.
Click to expand...

When I asked the designer about them at 2014 RMAF and why he was able to sell them so inexpensively, he said it was because the internals were stock NCore and a simple case.
 
mep said:
I'm surprised that NC400 and NC1200 based amps aren't much cheaper than what people are charging. Even though NC1200 modules are only supposed to be sold to manufacturers, brand new ones do show up on Ebay and sell for around $700 the pair with their SMPSs. Building a Class D amp using the assembled SMPS and the NC400/NC1200 modules takes about the same or less skill as assembling a computer from all the parts. Actually, assembling a computer from scratch and loading all of the software is much more complex. There is simply not much to a Ncore based Class D amp. Of course what we are seeing now is manufacturers machining their chassis from billet aluminum so you have a $1000 amp with a $6000 chassis that sells for many multiples of that number. The new Theta Class D amps are a bargain by comparison and they have linear power supplies to boot.
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In the 6moons review of the Atsah they have extended quotes from Bruno Putzeys who indicates that Class D amps are actually harder to design. An excerpt:

"Designing a class D amplifier, you start with an enormous handicap because it's trying to do everything but amplify audio. Where people get it utterly wrong is believing that these problems can't be solved. It simply takes much more dedication, theoretical study and attention to detail than it takes to making a good-sounding class A amplifier.

"With an amplifier like Ncore, getting the placement of a part or trace wrong by one millimeter is the difference between top performance and not getting the thing to work at all. If you want good performance, you can't use industry-standard Mosfet driver chips. You have to roll your own discrete drivers. The same for comparators which are either too slow or too noisy. Integrated op-amps are a favorite topic amongst audiophiles but they distort more than this entire class D amplifier. The truth is, a background in class A design is unhelpful for class D."
 
Welcome to the forum, thank you for joining.
 
joeinid said:
Welcome to the forum, thank you for joining.
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Thanks -- my first post here.
At any rate, I recently bought an Acoustic Imagery 'set' of the Jay Sho preamp and the Atsah amps. I should be posting some reactions after they've settled into their new home....
 
Correct me if I may be wrong, it's interesting to me how many new companies are popping up offering Class D type amps. Of course, more well known brands are coming on board, probably see the success or demand, I've never heard of this company before, there's Red Dragon who had a bit of a buzz going. Wyred4Sound has been fairly successful, there's others like Digital Audio Co., Channel Island, the guys from Nuforce have a new line, aw, I forget the name, all I'm getting are Cherry names. Merrill Audio started with just Class D amps. There's a host of these companies selling direct and showing on forums etc.

It just seems Class D really became popular when all these unknown companies began to bring the amps to market. Many of which contributed to Class D's bad rep and others showing the potential. Maybe it has something to do with the point made about Class D really being a new direction opposed to just another branch off Class A or A/B.
 
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