Atma-Sphere Class D… Amazing

@noske 


Figure 1 THD [dB] vs. Frequency @ 4Ω
Figure 2 THD+N [dB] vs. Power @ f=1kHz
Figure 3 Frequency Response @ Vi=2.83V
Figure 4 Frequency Spectrum (FFT) @ 1kHz, 1W, 4Ω
Figure 5 Intermodulation Distortion @ 18+19kHz, 1W, 4Ω
Figure 6 Frequency Spectrum (FFT) @ 1kHz, 10W, 4Ω
Figure 7 Intermodulation Distortion @ 18+19kHz, 10W, 4Ω
Figure 8 Frequency Spectrum (FFT) @ 1kHz, 100W, 4Ω
Figure 9 Intermodulation Distortion @ 18+19kHz, 100W, 4Ω
Figure 10 Output Power vs. VP @ 1% THD
Figure 11 Output Impedance vs. Frequency

@kuribo

I am not chasing my tail. If he measured all of the same things and showed them to you, what difference would it make? The better question would be, what measurement result would convince you it is a good value? You have already answered that question. The answer is, none.

You have your mind made up already. No homework necessary to come to that conclusion. According to you, the Hypex and Purifi measurements are already state of the art, which means they cannot be bested.

Just a little deductive reasoning would then show that you would proclaim it a poor value. You have your answer already and you know it. Quit playing the victim.

BTW, every amp I own is class D. I own a pair of speakers that use Hypex plate amps in them. Are they good? IMO yes. Is it a good value speaker system and do they sound really good? Yes and yes. Are they the best available? Uhhhh, no.

@kuribo That is quite a slab of tests. I think that someone who owns one will drop-ship one over to Amir at ASR. Probably a couple weeks turnaround.

I’d do it myself, but I can’t because I am on 50hz power.

Also, what I am thinking and I may be wrong, is that this is version 1 (that I know about). AGD are already into version 2, with version 3 probably next year.

This is unlike Purifi, which is settled and been in circulation for quite some years with its predecessor Hypex and variants.

They (Bruno and his silicon mates) are miles ahead in the abundance of research, and have the starters advantage compared to a new entrant in Class D - I think Ralph's amp have only been available this year?  

A couple of observations.

@kuribo has politely requested certain measurements be provided. He has the right to ask for those and @atmasphere also has the right to either provide those...or not. I’m not sure @kuribo would be a candidate to purchase in either case as @csmgolf has pointed out. Maybe Ralph would rather someone take the basic data he provides to make a broad decision to either go listen to them or not. Maybe Ralph could care less if the ASR crowd embraces what he has developed to even go hear them.

Here’s something that I’m sure Ralph would never do...but I suspect many others might. Why would I introduce a well made, well engineered excellent sounding amplifier at the $4-5k pricepoint rather than to exhaustively look for efficiencies and economies of scale in order to get the price down to $1k? Maybe I don’t want to build four times as many amplifiers? Maybe the money value of time to build an amplifier at the fit/finish I want to produce is X dollars and therefore I don’t want to compete in that space? My main reason to produce the more expensive product is that I simply don’t want to deal with the potential customer cross shopping Topping/Gustard/Hypex/Purifi while giving a reach-around to Amir and the other "if it costs more its a snakeoil ripoff" crowd. There are numerous examples that some potential customers simply aren’t worth the time it takes to turn them in to happy customers in order to head off the zero star Yelp review in their quiver.

I assume @kuribo is a sincere potential customer who has several measurement hurdles he wishes @atmasphere to clear before giving the amplifiers a listen. Give Ralph a little credit for reading between the lines that maybe, just maybe, the measurement police were unsuccessful in setting their trap.

@csmgolf

Um, the only one in this conversation that has their mind made up is you. What difference would it make if he published the measurements? How can I reasonably answer that unless he goes ahead and publishes them? As I said, if they are an improvement on the Hypex and Purifi designs, then arguably they have an added value that may justify the 3-4x great price. Why arguably? Because "value" is subjective and as I have also said repeatedly, the ultimate arbiter is how they would sound to me in my system in my room.

I have neither seen the measurements nor heard the amp, which would be the basis of any judgments. I have remarked that the amp, UNLESS it competes on an objective performance basis with its competitors (which we DO NOT KNOW), represents a poor value TO ME at its price point. This is called "a qualified opinion" and it is based on speculation, due to the lack of data.