Atma-Sphere Class D… Amazing

The OP has not been very clear as to whether Ralph suggested that he post his impressions. Ralph has a new product and he needs to get some attention over it. Even if not, it is pretty abundantly clear that the OP is already a fan of Atma-Sphere and is far from neutral. It is exceedingly rare for someone to go nuts over the sound of an amp. Amps have a subtle affect on overall sound, and there has never been an amp and likely will never be an amp that "bowls one over" immediately with sound from the heavens. I believe that amps are critically important to overall SQ but it takes months of living with an amp to assess it's character and attributes. So despite the silliness in this thread over non-related matters the circumspection is not surprising. 

And then we come to digital amps as a category. They are insanely cheap to manufacture as has been pointed out elsewhere in this thread. To my mind, a digital amp is a switching power supply built to drive loudspeakers. If there is a simpler way to harness power from the wall directly to the pre-recorded sound signal it has not yet been invented. Ralph has acknowledged that the box-a plain vanilla box at that-is the major parts cost of this product. When the best switching power supplies sound better than the best linear power supplies I will likewise believe that the best digital amps sound better than the best conventional Class A/Class A/B ss and tubed amps. 

Ironically enough, the discussion is still about distortion-that this digital amp has less of it. Here we go again-the old fallacy that the lack of distortion means more faithful sound reproduction. Loudspeakers are the number one producer of distortion. Distortion needs to be embraced, not made the focus of elimination. Even the power in the wall contains distortion. Harnessing raw power from the wall is not the answer. I wish Charles Hansen and Tim De Paravicini were alive to lend their voices to this discussion. I wish Nelson Pass would join. 

In summary, I have no doubt this amp sounds fine. Very fine. Just the same, it is bound to have sonic virtues and faults like any other amp. It won't make your grass greener, your hair thicker, or give you greater stamina in the bedroom. 

@atmasphere 

If it walks like a duck and sounds like a duck, it is probably a duck. 

From Wiki;

Class-D amplifiers work by generating a train of rectangular pulses of fixed amplitude but varying width and separation, or varying number per unit time, representing the amplitude variations of the analog audio input signal. The modulator clock can synchronize with an incoming digital audio signal, thus removing the necessity to convert the signal to analog. The output of the modulator is then used to gate the output transistors on and off alternately. Great care is taken to ensure that the pair of transistors are never allowed to conduct together, as this would cause a short circuit between the supply rails through the transistors. 

So yes, Class D is more accurately referred to as a "switching amplifier" rather than a "digital amplifier" but things get blurred when binary quantization is involved as binary quantization is at the heart of digital too. 

I find it interesting that in order to "cut me down to size" you chose to seize upon my bad choice of nomenclature (when I in fact used BOTH within the same paragraph!) rather than comment upon the bigger points made in my post.

I will say it again also-I have no doubt that this is a very fine sounding amp. I would expect nothing less from a man of your immense experience, intellect, and knowledge. I just get my hackles up a bit when someone like our OP posts a sensationalistic thread title and then waxes on and on. You don't want to be equated with Tekton do you?

I have only voiced one concern-the image put out by the OP that he did not expect to like this amp but it is "amazing". 

Here is the OP way back in 2019 saying he was excited to try it once it came out;   https://forum.audiogon.com/discussions/congratulations-atmasphere/post?postid=1840574#1840574

http://www.stereophile.com/content/benchmark-media-systems-ahb2-power-amplifier

Anybody remember this review? Look at JA's measurements and his concluding comment, "Benchmark Media Systems' AHB2 is an extraordinary amplifier. Not only does its performance lie at the limits of what is possible for me to reliably test, it packs high power into a very small package, especially when used in bridged-mono mode. It is truly a high-resolution amplifier"

And so I ask any of you, even in October of 2015 was this really an "extraordinary amplifier". In the literal sense of the word, not ordinary, maybe. In the intended sense of the word as something superlative in terms of measurements, maybe. A "high resolution amplifier"? BS. This is where JA gets caught up as an engineer in sound floors aka distortion masking. He falsely equates resolution with bits (in his flawed DAC reviews and measurement methodology) and distortion sound levels. But my recollection is that the unwilling innocent suckers who bought the amp back in 2015-2017 based in the superlative review were by and large not thrilled. KR never could formulate reliable subjective listening impressions imho. And KR's tin ear notwithstanding, humans can not assess amplifier performance the way they can assess transducer performance-it  takes long periods of time before the attributes of an amp are reliably evident. 

I have no axe to grind. When I find out that there is a switching amp that thrills listeners whom I trust, I will be glad to audition one. History has shown that switching amps can ace measurement testing and bore the death out of the listener. No meat to the bones. No there there. 

@jerryg123 

Call it Class A-G if it makes you happy but at it's core, the Benchmark was based on a switching power supply which is why it weighs 12.5 lbs. 

From S'Phile's coverage of RMAF 2013;

The Benchmark AHB2 amplifier, named in honor of the company's founder, Allen H. Burdick, who passed away just before the show, has a dynamic range claimed to approach 130dB, and outputs 100Wpc into 8 ohms, 170Wpc into 4 ohms and can be bridge to produce 340W into 8 ohms. THD+noise is said to be <–108dB relative to full output at 1kHz. John Siau explained that the THX modules are operated in a mode that gave the lowest noise and distortion rather than the maximum efficiency I wrote about in 2012. A key to the low THD is the use of 0.01%-tolerance resistors at critical points in the circuit. A switching power supply is used, Siau feeling that this was optimal because all the power-supply spuriae will be out-of-band and therefore more readily filtered. 

Ralph-would you be willing to discuss your Class D amp in terms of being true balanced (or not)? Please explain the circuit topology in terms of inputting and amplifying the input signal fully true balanced throughout. And assuming it does not, isn't this a compromise?

I have always expressed my appreciation for Ralph's contributions on this Board. Don't believe me? Look at my previous posting history and you will see for yourself. But up until now I never saw such promotion-as here-of his own product. 

In time, the tube amps will be gone. Not because of a lack of tubes but because they've been eclipsed and people will wonder why they go through the hassle when subjectively better sound is available at less cost. That hasn't happened yet simply because class D has taken some terrible missteps in the last 20 years.

How much hubris can a man possibly have to make such a pronouncement! This man has solved the problems leading to 20 years of "terrible missteps" of all that came before him? 

How is this pronouncement any different than those of the dumb prognosticators who declared vinyl dead once Philips-Sony came out with CD players in 1982 or so? Vinyl is far more of a "hassle" than tubes. 

Who is Ralph to declare that his subjective opinion of the sound of his own product is absolute? Ralph will no doubt diplomatically respond that he is not just referencing his own Class D amp. If so, than tell us Ralph which other Class D amps are you declaring to be subjectively better than the best tube amps other than your own? 

Ralph, how can you possibly tell the thousands of us with tube amps and preamps that if we only gave your Class D amp a good audition we would come to the realization that your Class D amp is subjectively superior? How can you then, in good conscience, even offer your tube amps for sale? 

As I type this I am wearing a mechanical watch, a Carl Bucherer Scubatec that costs the same as Ralph's amp, needs an expensive cleaning and lube every six to eight years, does not have the accuracy of a five dollar cheap digital watch, and has to kept on a watch winder or re-set once the mainspring's power reserve runs out. By analogy this would be the same as someone like Ralph stating that I should or will eventually realize that my preference for mechanical watches is folly. 

And Ralph, you have responded to virtually everyone else's questions and statements including those of the bizarre troll, and yet you won't respond to mine asking-earnestly- whether your class D amp has true balanced topology and if not, the sonic compromises if any? 

Ralph, I think you missed your calling. You should have been the US Ambassador to North Korea, China, or Iran. You have side-stepped your bold declaration that tube amps, the entire category bar none, are on their way out. But that is fine. I will not say another word in this thread and I truly wish you the best. I am confident enough in my high-end audio world to not let a different opinion-even yours-bother me any more than it has (which was relatively minor). Perhaps you could be so kind as to look me up three, five, or ten years down the road and tell me when my ARC Ref 150SE and ARC Ref 80 power amps have been rendered value-less. on the market so I can inquire of my accountant if I can declare a depreciation deduction.

I agree with Ralph regarding future sales of tube amps. Sure, some will always want to own one, but sales will erode dramatically over the next 10 years. Seems like a rather reasonable statement. Innovation in Class D amplification will continue and magnificent sounding options will be introduced at ever increasing speed delivering sonic improvements many felt impossible just a year or two ago. 

I said I was done but this is such nonsense. Amplifier design and amplifier performance has been dictated by the limitations of loudspeakers. There is no perfect amplifier because there is no perfect loudspeaker.  "Magnificent sounding options" and "Sonic improvements many felt impossible just a year or two ago". What flowery and prosaic language! That's a good one. The euphonic nature of tubes happens to suit the limitations of many loudspeakers in a manner that solid state often fails. Charles Hansen wrote about this towards the end of his life. https://www.youtube.com/watch?v=9L0k3-cporQ&t=5s  Think of an amp as a complimentary solution to a problem elsewhere in the chain, not the source of the problem and impediment to sonic bliss.

I have been a member here for ten years and I have just had my first post ever removed by the mods.

I had a short quote from a S'Phile interview with Charles Hansen which I duly attributed by author and source so that could not be the reason. 

I had a photo of the inside of the amp that is the subject of this thread and commented that the parts could not justify the price. That could not be the reason. Oh, yes, I think it was. 

I was never remotely involved in the ugliness of a certain poster. I bring that up only because of this- Tinear123 has a very nice system and I would be most interested to hear his long term assessment of this amp. He says he won't be posting because of the aforementioned ugliness. That's a shame. I hope you, Tinear123, should you see this, will reconsider.